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brian Rupnow
09-30-2015, 09:16 AM
I woke up this morning, thinking about an opposed twin i.c. engine. something along the layout of Jason's flat twin Boxter, only a bit cruder perhaps, with an open crankcase and exposed camshafts and crankshaft. I really like the knife and fork style con rod layout, and the fact that it lets the opposed cylinders set in line with each other. I haven't really sorted this through in my head yet, but this would probably mean two camshafts, one above the crank to run the right hand cylinder and one below the crank to run the left hand cylinder.-----Or perhaps both camshafts above the crankshaft, offset to each side. A single centrally located carburetor with long intake runners to each side---maybe. I have to think on this a while.---It feels interesting----Brian

brian Rupnow
09-30-2015, 11:07 AM
This is a new arrangement of connecting rod caps that I have just seen recently. I don't think it holds any real benefit except in a really small sealed crankcase, but it is certainly unique. The "knife and fork" arrangement of the rods lets you run two opposing cylinders in line with each other instead of having to offset them.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSY--OPPOSED%20TWIN_zpshzhkmq5q.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSY--OPPOSED%20TWIN_zpshzhkmq5q.jpg.html)

A.K. Boomer
09-30-2015, 11:47 AM
Hmmm - just wondering about the term "opposed twin" while still using the same crank pin...

it's hard for me to imagine having that configuration in front of you and not taking full advantage of it...

in some ways the shoe does not fit even though the cylinders are opposed and the pistons kinda are the pistons are following the same path back and forth and not in opposition from each other,,, this latter example is what makes a true 180 degree opposed twin so much smoother,,,

sure you can add one massive counterweight on the crank but we all know that's not a perfect solution due to the crank having to follow circular motion with it's weight and the pistons linear.

staggering the crank pins and offsetting 180 degree's is far better but will create a rocking motion of the block some as one cylinder will lead the front of the engine and crank and the other be behind it,,, typical boxer

using a fork rod for one piston on two crank journals 180 degrees opposed and off to each side of the center rod will alleviate this problem but you are still left with the the block wanting to torsionally rock with every compression and power stroke impulses esp. under load - also a most likely weaker connecting rod on the fork side that will also have a weight problem..

the only real perfect mechanical solution to an opposed twin is to utilize two crankshafts and gear them together --- now you have a perfect world,,, self cancelling 180 degree's and perfectly timed with no "weak links" ... make them straight cut gears and you will have one distinctive sounding engine esp. when that power stroke comes around and the engine is under load... even though the block will be internally stabilized put large enough flywheels on BOTH cranks and you have just stabilized the power output and in fact might have a small twin with a fairly low idle for a change...

ahidley
09-30-2015, 01:09 PM
Harley Davidson's have knife and fork. Vws, type1, aka bug engines, have flat four cylinders with one carb with long intakes. Perhaps combine the two and make your own?

TWiersma
09-30-2015, 01:17 PM
Maytag made a twin opposed that ran smooth as silk. You may want to look at one.

dp
09-30-2015, 01:23 PM
A master rod configuration as used in radial engines is another option and doesn't put threaded hardware in a shear force situation. The Harley pickle fork rod arrangement takes advantage of a split crank with a pressed in crank pin. This allows roller bearings because there's no rod cap joints.

brian Rupnow
09-30-2015, 01:45 PM
So---Perhaps we'll rethink this. I am being told that it's very bad juju to have opposed cylinders going to the same rod journal. I believe the folks who are telling me this. I wondered about it myself, but figured that if it wasn't a good idea somebody would speak up---and they did. I have enough problems with dynamic balance on my single cylinder engines without compounding it. So now--If the con rods go to seperate journals, 180 degrees apart, I can revert to the normal bolt on rod caps.

brian Rupnow
09-30-2015, 01:50 PM
Having been told that "Maytag engines run smooth as silk." I think I will take a page from Mr. Maytags book and start this over again. It appears that the Maytag was a 2 stroke, but having found that there is some serious Voodoo involved with 2 stroke engines, I will be going with 4 stroke, overhead valves.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/maytag%20engine_zpscq09nlo2.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/maytag%20engine_zpscq09nlo2.jpg.html)

A.K. Boomer
09-30-2015, 02:04 PM
Boy - talk about "back in the day"

"honey - if your heading into town pick up some fuel for me cuz I gotta wash some cloths tomorrow" ---- yes dear...

brian Rupnow
09-30-2015, 03:24 PM
Alright!! ---This is more like it. Thank you Malcolm Stride. Thank you Canadian Cub!!!---This is why we always save our 3D models. I have miles to go before I sleep, but I think I'm on the right track now.----Brian
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zps8scuvt6y.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zps8scuvt6y.jpg.html)

brian Rupnow
09-30-2015, 03:40 PM
Size looks about right!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE%20DRAWING_zpsydrftk7w.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE%20DRAWING_zpsydrftk7w.jpg.html)

A.K. Boomer
09-30-2015, 04:16 PM
Muchie better :)


important to note; and I know your illustration is just a rough draft, but take a look at the maytag in comparison your your sketch up, notice on the maytag all that is used to separate the journals is the most minimum of thin plates - just enough to keep the crank strong enough - very critical area here not just to keep the entire unit more compact but more so to reduce critical crank "rocking" esp. then the two cylinders are going through their TDC/BDC phase together,,, the less "leverage" in this area the better - the more minimal you can keep it the smoother the engine will be...


http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/maytag%20engine_zpscq09nlo2.jpg[/URL]

http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zps8scuvt6y.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zps8scuvt6y.jpg.html)

Guido
09-30-2015, 04:21 PM
Pull up McCulloch drone engine(s) of WWII. 2, 4 and 6 cylinders, what's yer pleasure. Aircooled jugs, flat crank, carburetor, 2 cycle, and-------contrarotateing props to boot.

--G

flylo
09-30-2015, 04:55 PM
I built a small aircraft engine from a french citroen engine, very smooth & works great. 4 stroke, oil cooled. Take a look at one. Put's out 45 HP now & 70 with the turbo I have to go on it.

rklopp
09-30-2015, 05:26 PM
I see a similarity to the Upshur Twin design, but the latter has a closed crankcase.

Yow Ling
09-30-2015, 05:55 PM
Is purple steel the best choice for a crankshaft?

J Tiers
09-30-2015, 06:18 PM
Do a 4.... it will balance better, if not 100% perfectly as far as internal balance is concerned.

For odd 2 cyl opposed, I believe the Johnson Waterbug has the connecting rods bent to clear each other.

A.K. Boomer
09-30-2015, 06:34 PM
the connecting throws on the old 40 hp VW's used to shoot craps every now and then but in general this was not due to normal "running" conditions,
the carbs lacked an idle shut-off solenoid and the engines liked to diesel like crazy once shut off, sometimes for minutes at a time if people let them - all kinds of strange forces at work

I remember ones that people would keep driving even with a broken crank, if it was in the middle the flywheel side would still start both individual pieces as the broken parts could not escape each other and would just rattle back and forth but still propel the other side, terrible sounds, but people would still try to drive them...

trick with the old bugs that did not have an idle shut off solenoid was to just put it in second gear with the parking brake on - load the clutch - turn ignition off... it was a must do - but not all people did it...


http://images.thesamba.com/vw/gallery/pix/1092392.jpg

dp
09-30-2015, 06:35 PM
Pull up McCulloch drone engine(s) of WWII. 2, 4 and 6 cylinders, what's yer pleasure. Aircooled jugs, flat crank, carburetor, 2 cycle, and-------contrarotateing props to boot.

--G

Those were awesome engines. Incredibly simple and nearly bullet-proof. The cylinders fired in opposed pairs.
http://www.pra.org/publicdl/engines/McCulloch%20Engine%20Manual/

The guy that zero-timed my Ercoupe engine had several in his shop in various states of repair, including the gear boxes for the props.

brian Rupnow
09-30-2015, 06:45 PM
Is purple steel the best choice for a crankshaft?

Purple steel is the strongest. Alloyed with Kryptonite!!!

Toolguy
09-30-2015, 06:46 PM
Is purple steel the best choice for a crankshaft?

That's for when you're going to use Royal Purple motor oil.

brian Rupnow
09-30-2015, 06:57 PM
I have found that by using a 36 tooth and an 18 tooth gear, I can avoid having to cut a jockey gear to fit between them since I don't have the same physical constraints as the original engine. I have to do a bit more modeling to decide whether I like them, or if they will look too big and "clunky".
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zps9y8ny0h0.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zps9y8ny0h0.jpg.html)

boaterri
09-30-2015, 07:02 PM
You might also look at the Onan generators used in RVs and TV live trucks. Horiz opposed twins firing at the same time.

Rick

dp
09-30-2015, 07:03 PM
Why the extra gear? You should be able to drive both cams from the same end, and can even use off the shelf belt drive hubs and a serpentine cog-belt. The cams don't care which way they turn so long as they're lobed and timed right.

Cuttings
09-30-2015, 07:04 PM
Brian - I noticed that the crank throws in the maytag engine are round discs. This would act like flywheels right in the middle of the engine and also probably contribute to balancing.

brian Rupnow
09-30-2015, 09:03 PM
Don't ask me what I'm doing----I'm not sure myself!! Just messing about, modeling, figuring out how I'm going to do this. Right now it's looking like two pieces of aluminum angle, right and left hand bolted together to form the main body, but that may change.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zpsu0o2xm2f.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zpsu0o2xm2f.jpg.html)

brian Rupnow
09-30-2015, 09:07 PM
Brian - I noticed that the crank throws in the maytag engine are round discs. This would act like flywheels right in the middle of the engine and also probably contribute to balancing.

Cuttings---you are right, but I think it was just the way they fabricated the crank. It would be a pig of a thing to machine from solid. Those engines had an external flywheel, and mine will too.

becksmachine
10-01-2015, 12:29 AM
the only real perfect mechanical solution to an opposed twin is to utilize two crankshafts and gear them together --- now you have a perfect world,,, self cancelling 180 degree's and perfectly timed with no "weak links" ... make them straight cut gears and you will have one distinctive sounding engine esp. when that power stroke comes around and the engine is under load...

Fairbanks Morse submarine diesels and some Junkers (?) aircraft diesels.

Dave

J Tiers
10-01-2015, 01:44 AM
Cuttings---you are right, but I think it was just the way they fabricated the crank. It would be a pig of a thing to machine from solid. Those engines had an external flywheel, and mine will too.

Absolutely.

Disks are not part of crankshaft, it's an assembly, 2 shafts, pin(s), disks. Lots of engines like that. Gravely, HD, that Maytag, etc.

thaiguzzi
10-01-2015, 05:57 AM
The most famous air cooled Boxer 2 cylinder motor of all time, BMW. I'm not sure, but they had a single crank journal with both rods side by side, and definetely a single cam. Keep stuff simple.

A.K. Boomer
10-01-2015, 09:06 AM
The most famous air cooled Boxer 2 cylinder motor of all time, BMW. I'm not sure, but they had a single crank journal with both rods side by side, and definetely a single cam. Keep stuff simple.


I am sure they did not have a single crank journal for both rods to share - if that was the case they would shake worse than a harley...


Depending on design there were both single cam push rod and twin cam SOHC --- there are also DOHC which makes for 4 total...
pic shown is gear to gear DOHC 4 cam, note the offset jugs and the crank design to keep the throws 180 degree's apart;


https://s.yimg.com/fz/api/res/1.2/hZK2rnLwN75iIDohj6cNJw--/YXBwaWQ9c3JjaGRkO2g9Njg2O3E9OTU7dz05NzE-/http://www.cpuhunter.com/wp-content/uploads/2013/02/2013-BMW-R1200GS-Liquid-cooled-1170cc-Boxer-Two-Cylinder-Engine_2.jpg

JCHannum
10-01-2015, 09:45 AM
Why take the easy way out? Here's an opposed twin aircraft engine circa 1910, essentially a four cylinder, using a scotch yoke.

http://www.billzilla.org/ffeng.gif

A.K. Boomer
10-01-2015, 10:06 AM
I don't think those things lasted too long --- I also know they had terrible balance - although the pistons don't have to have skirts and can be kept small how do you provide lubrication to them?

think of all that mass going from side to side like that and also having to take the scotch yoke with it...

might have had a good power to weight ratio for it's day - for a little while before it hand-grenaded :p

A.K. Boomer
10-01-2015, 10:14 AM
You know they just would have killed to get their hands on this,

4.5 hp per pound,,,

400 hp and just 8lbs heavier than a bag of cement...

http://www.motorauthority.com/news/1086869_nissan-reveals-zeod-rcs-400-hp-3-cylinder-engine-confirms-2015-lmp1-entry

flylo
10-01-2015, 10:29 AM
Those were awesome engines. Incredibly simple and nearly bullet-proof. The cylinders fired in opposed pairs.
http://www.pra.org/publicdl/engines/McCulloch%20Engine%20Manual/

The guy that zero-timed my Ercoupe engine had several in his shop in various states of repair, including the gear boxes for the props.

Did your Ercoupe have pedals?

J Tiers
10-01-2015, 10:43 AM
Why take the easy way out? Here's an opposed twin aircraft engine circa 1910, essentially a four cylinder, using a scotch yoke.

http://www.billzilla.org/ffeng.gif

Sheesh... look at that thang.....

Double-acting pistons, surface carbs, with fuel pre-heated on cylinder, scotch yoke and rod mass.... wild.....

brian Rupnow
10-01-2015, 11:53 AM
This is one of those rather unusual cases where, after massive amounts of cutting and carving and rearranging, everything seems to work just fine by bolting two pieces of 1/2" thick aluminum angle together toe to toe. Everything fits, clears, and seems to look surprisingly good. I did lengthen the connecting rods by 1/4" thereby moving the cylinders out 1/4" more from the center-line of the crankshaft to give myself a bit more room. I will make gear covers---Not so much as a safety factor, but as a noise dampner. Those meshing spur gears make a heck of a racket. It would be nice to machine the gear covers from clear Lexan so the gears remain visible but the racket is kept quieter. It appears that the two angles can be machined to finished size, bolted together and dowelled, then drilled and reamed thru both sides in one set-up for oilite bronze bushings for the crankshaft and both camshafts. The angles could then be unbolted to install the crankshaft and camshafts, then reassembled.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zpsag1rvb6o.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zpsag1rvb6o.jpg.html)

Toolguy
10-01-2015, 12:24 PM
Looks good. Simple is always the best. With an assembly like that, I like to make the dowel pin holes in the thru hole side a .001 press fit and the pin holes in the blind hole side .001 slip fit. You may want to rearrange the joints so the dowel pins are parallel to the shafts if possible, for ease of assembly and disassembly. You could put the joints on the corners away from the cylinders.

RWO
10-01-2015, 01:18 PM
Why two camshafts? A single cam with just two gears would be even simpler.

RWO

dp
10-01-2015, 01:33 PM
Did your Ercoupe have pedals?

It did. The nose gear was still coupled to the ailerons.

brian Rupnow
10-01-2015, 01:35 PM
My intent all along has been to run this thing open crankcase---no top on it. Drill oil galleries down thru from the top to the crankcase and camshaft bushings and just give the cams and con rods a squirt of oil on start up. This engine will never see long duration runs nor heavy service. I want it to run slowly and use a 6 inch diameter flywheel as shown with vanes cut into the outer inch to act as a fan to blow on the cylinders to cool them. This makes for a rather strange looking base but I need that much height in the base to get flywheel clearance.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zpsh3dukjha.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zpsh3dukjha.jpg.html)

A.K. Boomer
10-01-2015, 01:41 PM
Your a fast worker Brian --- looking good :-)

brian Rupnow
10-01-2015, 01:57 PM
Thanks boomer---I didn't like that first base---It looked too much like the clock my grandma had on her fireplace mantle!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zpsr7tjuodp.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zpsr7tjuodp.jpg.html)

The Artful Bodger
10-01-2015, 02:59 PM
Why take the easy way out? Here's an opposed twin aircraft engine circa 1910, essentially a four cylinder, using a scotch yoke.

http://www.billzilla.org/ffeng.gif

Thats Richard Pearse's engine which I think was about 1903 (there is some debate re the actual date!).

Willy
10-01-2015, 03:07 PM
Why the extra gear? You should be able to drive both cams from the same end, and can even use off the shelf belt drive hubs and a serpentine cog-belt. The cams don't care which way they turn so long as they're lobed and timed right.

This was my first thought as well, utilizing two camshafts makes only a little more engineering sense than incorporating the use of 4 individual cams when one will do.
Unless one is going to an overhead cam system the added complexity of using two separate camshafts and the related mounting, covers, and gear drives make no sense.
A single centrally positioned camshaft reduces redundancy. Give it some thought.

rythmnbls
10-01-2015, 03:12 PM
I am sure they did not have a single crank journal for both rods to share - if that was the case they would shake worse than a harley...


Depending on design there were both single cam push rod and twin cam SOHC --- there are also DOHC which makes for 4 total...
pic shown is gear to gear DOHC 4 cam, note the offset jugs and the crank design to keep the throws 180 degree's apart;


https://s.yimg.com/fz/api/res/1.2/hZK2rnLwN75iIDohj6cNJw--/YXBwaWQ9c3JjaGRkO2g9Njg2O3E9OTU7dz05NzE-/http://www.cpuhunter.com/wp-content/uploads/2013/02/2013-BMW-R1200GS-Liquid-cooled-1170cc-Boxer-Two-Cylinder-Engine_2.jpg

That's an interesting pic of the innards of a BMW boxer, the drive to the right hand crankshaft is a bit complex, I s'pose they were out of space on the main crank and had to drive it from somewhere else, but I can't make it out clearly in the pic.

Steve.

Toolguy
10-01-2015, 03:14 PM
One camshaft down the middle would make the pushrods long and flexible in a situation where they are getting a significant side load. As it is modeled they are very well supported in that area.

Willy
10-01-2015, 03:28 PM
One camshaft down the middle would make the pushrods long and flexible in a situation where they are getting a significant side load. As it is modeled they are very well supported in that area.

This simply is not an issue. Look at at just about any pushrod actuated opposed cylinder engine and you will see that a single centrally located camshaft is the design of choice.

VWs come to mind, as do Lycoming and Continental aircraft engines.

http://gnaircraft.com/wp-content/uploads/2011/01/aircraft-engine-products.jpg

http://www.aero-news.net/images/content/genav/2004/Superior-Vantage-0404c.jpg

brian Rupnow
10-01-2015, 03:46 PM
So---This is what I would like to do with the flywheel. The flywheel is 6" maximum outer diameter overall x 3/4" thick, made from either brass or mild steel or a combination of the two. The outer band is 1/8" thick The "blades" as I have shown them are 3/16" thick. The outer diameter of the main flywheel body is 4 1/4", and the bore is 3/8". The recess shown in the sides of the flywheel is somewhat irrelevant (I know how to do that.) Now remember--This is a "best case" scenario". I do not have the capacity to machine it from solid. I do have the capacity to cut 3/16" wide slots x 1/8" deep in the outer diameter of the main body to act as "positioners" for the 8 "blades", but the body would soak up so much heat that it would be a real bear to solder the blades in place as individual entities, and that leaves me having to solder or bolt the outer rim into place.--I want the flywheel to be concentric---I hate flywheels that look like they are "orbiting" the crankshaft. I could probably even use #2-56 s.h.c.s. to bolt the blades on, but that's a lot of tapping with a fairly fragile tap. (The head on a #2-56 shcs is small enough to bury in a counterbore in the 3/16" wide blades.) I'm open for suggestions!!--Brian
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zpsfgmsmccd.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINE_zpsfgmsmccd.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OPPOSED%20PISTON%20FAN%20FLYWHEEL_zpsbq6uh6y5.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OPPOSED%20PISTON%20FAN%20FLYWHEEL_zpsbq6uh6y5.jpg. html)

brian Rupnow
10-01-2015, 05:31 PM
I have one last piece of bronze left from the government scale checking weight that I was given a couple of years ago. It measures 5 3/4" diameter x 1 5/8" thick. I am so intrigued by the "flywheel with cooling vanes" that I may try to make the flywheel first. :eek::eek: I will have to cobble up some method of slicing it in half. The guy I buy my steel from has a giant bandsaw that he has been using to slice of 1" lengths of this thing for me to make flywheels from, at $10 per slice, but it is now to thin to hold in his saw vice.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/LAST%20PIECE%20OF%20BRASS%20002_zps4rwp6xge.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/LAST%20PIECE%20OF%20BRASS%20002_zps4rwp6xge.jpg.ht ml)

JSR
10-01-2015, 05:38 PM
Brian

Make the center of the flywheel and slot to insert the vanes. Use superglue to hold the vanes for the next portion of the assembly. Make the outer ring .001 or .002 under size, then heat it up and drop the center assembly into it, like putting tires on a steam locomotive. Might work!

John

CarlByrns
10-01-2015, 06:11 PM
The guy I buy my steel from has a giant bandsaw that he has been using to slice of 1" lengths of this thing for me to make flywheels from, at $10 per slice, but it is now to thin to hold in his saw vice.


You can fasten (bolt, screw or interference fit) the brass to a mandrel. Clamp the mandrel in the saw and take the cut.

CarlByrns
10-01-2015, 06:18 PM
So---This is what I would like to do with the flywheel. The flywheel is 6" maximum outer diameter overall x 3/4" thick, made from either brass or mild steel or a combination of the two. The outer band is 1/8" thick The "blades" as I have shown them are 3/16" thick. The outer diameter of the main flywheel body is 4 1/4", and the bore is 3/8". The recess shown in the sides of the flywheel is somewhat irrelevant (I know how to do that.) Now remember--This is a "best case" scenario". I do not have the capacity to machine it from solid. I do have the capacity to cut 3/16" wide slots x 1/8" deep in the outer diameter of the main body to act as "positioners" for the 8 "blades", but the body would soak up so much heat that it would be a real bear to solder the blades in place as individual entities, and that leaves me having to solder or bolt the outer rim into place.--I want the flywheel to be concentric---I hate flywheels that look like they are "orbiting" the crankshaft. I could probably even use #2-56 s.h.c.s. to bolt the blades on, but that's a lot of tapping with a fairly fragile tap. (The head on a #2-56 shcs is small enough to bury in a counterbore in the 3/16" wide blades.) I'm open for suggestions!!--Brian


Live Steam magazine ran an article where the author built up a spoked flywheel by turning the hub and rim out of one piece of brass stock, leaving a disc of material holding the rim and hub concentric. He then drilled the holes for the spokes and soldered them in. Then he faced of the remaining disc, leaving a spoked flywheel.

brian Rupnow
10-01-2015, 06:54 PM
Carl---the piece is solid. no center hole to go on a mandrel. Final center hole will be only 3/8" diameter----too small to mount blank on for cutting in a saw. JSR--I kind of like your idea and I might use a variation of it.

brian Rupnow
10-01-2015, 06:57 PM
Tomorrow I will take a closer look at a single, center mounted camshaft.

tc429
10-01-2015, 07:06 PM
So---Perhaps we'll rethink this. I am being told that it's very bad juju to have opposed cylinders going to the same rod journal. I believe the folks who are telling me this. I wondered about it myself, but figured that if it wasn't a good idea somebody would speak up---and they did. I have enough problems with dynamic balance on my single cylinder engines without compounding it. So now--If the con rods go to seperate journals, 180 degrees apart, I can revert to the normal bolt on rod caps.

didnt read the whole thread, but glad to hear rethinking single pin crank... I had a Saito FA-90T model airplane engine, twin opposed with a single pin crank, worst motor I ever had. opposed pistons on one crank pin= no crankcase pressure, combustion gasses build up in the case, on glow fuel, after burning its pretty acidic, ate bearings often. Saito went so far as to put a small vane pump in the case to help purge it, but didnt work all that well apparently... eventually, I put a small oil tank in it hooked to the vane pump, notched the vanes a little so it would take oil slowly, maybe a ounce on a 10 minute flight, that seemed to take care of the bearing issue. other problem was the exhaust pulses 90 degrees apart- both pipes tapped for fuel tank pressure, but never worked- partially closing one exhaust opening , only using that side to the tank helped, but didnt help power... later put a perry oscillating pump(uses torsional vibration to advantage- a 'slug' piston floats free in a case with checkvalves at either end- worked great) on it, and opened up the exhaust, ran pretty decent, but weak for a .90- last ditch effort, I took the cams out and hand ground(!) the base circle down .030" to increase valve lift (was careful not to hit the ramp/tops of the lobes, figured the base circle had clearance anyways- by not changing the ramps any, surely widened the overlap- but anyways, it ran awesome after that, had a harley-like little lope at idle, throttle response was instant, swung a 16-8 prop with no problem.
Saito DID use two carburetors- the 90 degree intake pulses would be a issue with a single carb... lots of reasons a two pin crank would be best, balance(both weight wise, and torsional vibration-wise), plenty of crankcase pressure/vacuum pulses to purge things, single carb wth twice the intake pulses, etc...

J Tiers
10-01-2015, 08:47 PM
My intent all along has been to run this thing open crankcase---no top on it.....

Keep some towels handy, it will likely sling oil out the top like crazy.

Stepside
10-01-2015, 09:22 PM
Brian

Layout your flywheel full size. There are places where you are going to waste the material between the vanes. Drill and tap some threads in the waste and drill the same hole pattern in some scrap so you can screw them together. Clamp on the scrap piece and slice off your part. If you use a taper tap and bottom tap you will not have any holes in the part you are not using. My favorite scrap for this operation is some large angle with the clamping holes in the upright leg.

thaiguzzi
10-02-2015, 01:27 AM
I am sure they did not have a single crank journal for both rods to share - if that was the case they would shake worse than a harley...


Depending on design there were both single cam push rod and twin cam SOHC --- there are also DOHC which makes for 4 total...
pic shown is gear to gear DOHC 4 cam, note the offset jugs and the crank design to keep the throws 180 degree's apart;


https://s.yimg.com/fz/api/res/1.2/hZK2rnLwN75iIDohj6cNJw--/YXBwaWQ9c3JjaGRkO2g9Njg2O3E9OTU7dz05NzE-/http://www.cpuhunter.com/wp-content/uploads/2013/02/2013-BMW-R1200GS-Liquid-cooled-1170cc-Boxer-Two-Cylinder-Engine_2.jpg

You are indeed correct. I just got my BMW OHV airhead book out by Bruce Peston, and yes, 180 degree apart seperate journal. My bad. I was getting confused with Moto Guzzi (God's gift to motorcycling) 90 degree v twin cranks.

AntonLargiader
10-02-2015, 02:58 AM
BMW motorcycle boxer engines have gone through a few major revisions over the years. You are more or less duplicating something from the 1940s with the twin camshafts, as found on the R51/2 model. Single, centrally mounted camshafts came in the 1950s and are as simple as it gets. R50, R60 sort of stuff.

Seems to me that for the size you are talking about, if you're going to have two camshafts you might as well go OHC and do away with the pushrods.

brian Rupnow
10-02-2015, 12:20 PM
I've spent the best part of this morning tweaking the model. I had the overlap in the main frame going the wrong direction, so I changed that so the bolts. dowel pins, and crank and camshafts were all in the same plane. I went to a centrally mounted single camshaft, which does indeed simplify things.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsydtzkbof.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsydtzkbof.jpg.html)

dp
10-02-2015, 12:55 PM
Sorry to see the twin-cam design go by the wayside. You were this >< close to a gearless overhead cam engine design :)

RWO
10-02-2015, 12:56 PM
Breaker points need to be on camshaft.

RWO

MinnesotaHSM
10-02-2015, 01:19 PM
Your flywheel design made me instantly think of the Maytag Twin Cylinder and single cylinder engines that used to power washing machines.
https://www.google.com/search?q=maytag+twin+cylinder+engine&ie=utf-8&oe=utf-8

- Tom

brian Rupnow
10-02-2015, 01:30 PM
Your flywheel design made me instantly think of the Maytag Twin Cylinder and single cylinder engines that used to power washing machines.
https://www.google.com/search?q=maytag+twin+cylinder+engine&ie=utf-8&oe=utf-8

- Tom

Perhaps you should look at the whole thread.

brian Rupnow
10-02-2015, 01:32 PM
Breaker points need to be on camshaft.

RWO

No--If the breaker points are on the crankshaft, they fire on every engine rotation. Ignition wire is split and goes to both cylinders.

old mart
10-02-2015, 02:11 PM
Breaker points on the crankshaft require an ht coil which has the secondary winding double ended. Each cylinder gets a wasted spark on the exhaust stroke which doesn't matter. The smaller Honda twins with 360 degree cranks had this arrangement. I had a Honda Benley 200cc twin with this arrangement. In theory, having the polarity of the spark different in each plug would be detrimental, but I never noticed any difference in plug erosion.

brian Rupnow
10-02-2015, 04:38 PM
This brings up a good point. I already have an "ignition box" containing a standard 12 volt automobile coil, which is wired appropriately with two leads and a high tension wire. It runs in conjunction with an extra 12 volt battery that I have had for years. Since I have 8 or 10 different engines, all single cylinder, with their own points and condensers, I can "plug and play" whatever engine I want into the "ignition box". I did this because coils are expensive at about $50 each. i don't want to buy an electronic ignition nor a special coil. I think I can probably make a "splitter box" out of non conductive material which has the coil wire connected to one port, with two separate ignition leads coming out of it, one going to each sparkplug. I see no reason that wouldn't work. Has anybody done that?

brian Rupnow
10-02-2015, 05:06 PM
Okay---now we're at the "what if" stage.--I'm not likely to do this, but IF I decided not to run the engine with an open crankcase, it would be simple to add a couple of gaskets and a top cover. If I ran a cover, then I would need to run some oil in the base for splash lubrication.--As Jason pointed out, this would lead to other issues, with the clockwise rotation flinging oil into the "down-wind" cylinder and loading it up with oil. Really, at this point I'm just "imagineering".
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpspzhmkpzf.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpspzhmkpzf.jpg.html)

tc429
10-02-2015, 05:15 PM
or... run premix, put reeds under the carb, feed the crankcase, 'vent' to intakes...if you 'pack' the case clearances, you could build in a 'free' 2:1 supercharger and keep the case clean/cool and lubed :) will need some seals added though, might be a good idea anyways to keep oil from slinging off your fan/flywheel.

Id keep the case cover/intake under carb, and intake tubes from crankcase made of clear materials, just so at low rpm you could see the 'puffing'- and add a blowout disc in case of a backfire :)

if you run glow fuel, no ignition needed, just a 1.5v battery- less volaile/dangerous than gas, and with fulltime plug heat, you could 'lug' the rpm way, way down for the cool visuals of all the little parts moving, intake uffing, etc... that Saito twin I had pulled enough at idle the piper cub wanted to float forever- put a battery on the plugs that switched on at idle, it would idle so slow it would just go tick-tick-tick...really helped it settle faster for landing :)

old mart
10-02-2015, 06:14 PM
Concerning getting two HT outputs from one coil, a car coil would not work, if you split the lead between two plugs, one would spark and the other not. Apart from the impossibility of matching plugs, the question of one cylinder having different temperatures and pressures to the other at the moment of ignition would make for poor or no running. Two car coils with their LT connections in series would work, preferably 6V coils for 12V, otherwise a 24V supply for 12V coils.

dp
10-03-2015, 12:33 AM
A Harley dual-fire coil is reasonably priced.

http://www.ebay.com/itm/DUAL-FIRE-IGNITION-COIL-FOR-HARLEY-DAVIDSON-BIG-TWIN-AND-SPORTSTER-MODELS-/121769975216?hash=item1c5a0e5db0&vxp=mtr

John Stevenson
10-03-2015, 01:10 AM
Is purple steel the best choice for a crankshaft?

Darker the colour the better the heat treatment :p

thaiguzzi
10-03-2015, 01:43 AM
I've spent the best part of this morning tweaking the model. I had the overlap in the main frame going the wrong direction, so I changed that so the bolts. dowel pins, and crank and camshafts were all in the same plane. I went to a centrally mounted single camshaft, which does indeed simplify things.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsydtzkbof.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsydtzkbof.jpg.html)

That's more like it! It is now an airhead OHV BMW. Proper. Now attach a clutch to the flywheel, transmission to the clutch, shaft drive coming out of the transmission to the rear wheel...

Paul Alciatore
10-03-2015, 03:52 AM
If you want the best balance, I think this would do it. The pistons are going in opposite directions, the crank shaft is perfectly balanced, the connecting rods are making opposite motions, and finally, there is no rotational imbalance about the axis perpendicular to the page of the drawing.

http://img.photobucket.com/albums/v55/EPAIII/Web%20Post%20Photos/EngineBnW_zpsi6flul0g.jpg (http://smg.photobucket.com/user/EPAIII/media/Web%20Post%20Photos/EngineBnW_zpsi6flul0g.jpg.html)

Unless I messed something, it should purr like a kitten.

Oh, I showed it with all pistons firing at the same time, but the two pairs could be 90 degrees apart for a two cycle (1&2 and 3&4) or fire on alternate rotations for a four cycle (1&4 and 2&3).

Lew Hartswick
10-03-2015, 08:35 AM
<. Two car coils with their LT connections in series would work, preferably 6V coils for 12V, otherwise a 24V supply for 12V coils. >

Exactly what my NSU Sport Prinz used. It was a two cyl in line and both plugs fired every rev. (between the exhaust and intake it doesn't matter)
...lew...

brian Rupnow
10-03-2015, 09:09 AM
A Harley dual-fire coil is reasonably priced.

http://www.ebay.com/itm/DUAL-FIRE-IGNITION-COIL-FOR-HARLEY-DAVIDSON-BIG-TWIN-AND-SPORTSTER-MODELS-/121769975216?hash=item1c5a0e5db0&vxp=mtr

Alright!!--I'm convinced. a dual Harley coil it will be. Thanks DP.

A.K. Boomer
10-03-2015, 09:33 AM
Before the big craze (and a good one) of individual ig. coils for every plug most typical in-line fours had two separate coils and each coil had two high voltage leads coming out of them and they just fired off one cylinder while it was on compression stroke and one at the end of exhaust ---- dirt cheap at my local U pull and pay salvage yard for like 5 bucks a copy...

as you can guess this system wore spark plugs out at double the rate...

dp
10-03-2015, 10:49 AM
If you want the best balance, I think this would do it. The pistons are going in opposite directions, the crank shaft is perfectly balanced, the connecting rods are making opposite motions, and finally, there is no rotational imbalance about the axis perpendicular to the page of the drawing.

You can shorten the crankshaft by re-arranging the cylinders and crank throws.

http://metalworkingathome.com/images/shorter.png

J Tiers
10-03-2015, 11:01 AM
You can shorten the crankshaft by re-arranging the cylinders and crank throws.

http://metalworkingathome.com/images/shorter.png

If you do that you don't balance the masses quite as well. Paul's way is externally balanced as well as a 4 cyl can be. A 6 can be about perfect. But Mr Rupnow is doing a twin.

On that point, with bent rods, the cylinders could be directly opposite, and reduce the "couple" introduced by the pistons being offset.

dp
10-03-2015, 11:27 AM
If you do that you don't balance the masses quite as well. Paul's way is externally balanced as well as a 4 cyl can be. A 6 can be about perfect. But Mr Rupnow is doing a twin.

On that point, with bent rods, the cylinders could be directly opposite, and reduce the "couple" introduced by the pistons being offset.

It's not a contest. It is a demonstration of how configurations affect optimizations. Paul went for vibration, I went for compactness. With a desktop model engine I doubt the builder would experience a significant problem with either configuration. Using picklefork rods will also align the cylinders. Same with using master rods. Just depends on what you optimize for. I'm pretty sure we all know how many cylinders are in Brian's design not that it matters to the conversation.

brian Rupnow
10-03-2015, 04:19 PM
I shortened that base up as much as I could, and I flipped the toes of the angle frame to get my cylinder bases all on one surface. I like the proportions much better this way, although it will have to set up on a wooden base to get flywheel clearance. Dang, I like that flywheel!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsbemchhef.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsbemchhef.jpg.html)

Paul Alciatore
10-03-2015, 04:29 PM
Absolutely true. I was just trying to show that a complete balance was possible. And yes, it does require a longer crank shaft and crank case. That is probably why it is not used very much. The extra reduction in the vibration is probably not worth the extra expense and size in the real world. I searched for a drawing of my idea and could not find one. All the examples of four cylinder, opposed engines used the arrangement that dp rearranged my drawing to.

Just spit-balling.




It's not a contest. It is a demonstration of how configurations affect optimizations. Paul went for vibration, I went for compactness. With a desktop model engine I doubt the builder would experience a significant problem with either configuration. Using picklefork rods will also align the cylinders. Same with using master rods. Just depends on what you optimize for. I'm pretty sure we all know how many cylinders are in Brian's design not that it matters to the conversation.

J Tiers
10-03-2015, 05:03 PM
It's not a contest........... I'm pretty sure we all know how many cylinders are in Brian's design not that it matters to the conversation.

Well it wasn't until you brought it up. For no known reason in the universe.

We were discussing vibration, and the best balance is with the other setup, although most do seem to use the one you show. In that sense I suppose it IS a contest, seeking lower vibration. (but no need to be a smarty-pants about it) The single crankpin was already discarded on that basis.

The off set rods HAVE been used, and would improve a twin somewhat over offset cylinders. As I mentioned, the Johnson Waterbug boat motor used them. I expect they would improve this one as well, and strength won't likely be an issue.

Among 4cyl, even aircraft engines, like the Continental A-40, used the more compact setup, for various guessable reasons. The A-40 probably because it allowed both cylinder heads to be identical dual units, and simplified the cam.

But 4cyl practice is not germane to the issue here, as a twin is the object in question.

Using picklefork rods would put both rods on one pin, most likely, which was already discarded. Otherwise you would need two throws for one rod.

A.K. Boomer
10-03-2015, 06:28 PM
JT your talking to the wrong guy, you and Paul are trying to achieve good balance and therefore low vibration...

that does not compute to him... he does not know what that is...

in order to try and relate to people you have to know what they ride,,, try hitting him in the side of the head with a big rock lol
easy to sneak up on em cuz they can't see out of their side view mirrors :p

Paul Alciatore
10-03-2015, 06:48 PM
I was not trying to start a contest or anything, just putting up an idea for discussion.

Any mechanism is a bunch of compromises. An old saying in the engineering world says that; I can do it fast, I can do it cheap, I can do it well: pick ANY TWO. Everything is a compromise and you only need to look at our very diverse world to see that many choices are taken. None are necessarily, "The Best." That's what makes it fun.

As for the OP, yes I know he was discussing a two cylinder design. There have been other discussions on this. And I am sure he is going to stick to that two cylinder idea. I was just expanding some. I wondered if those two cylinders could be on the same axis with only the connecting rods being displaced to the sides of those pistons. Probably increase the wear on the knuckle pins.

A.K. Boomer
10-03-2015, 06:50 PM
Pauls drawing is interesting and does look mechanically balanced at a glance - but there's all kinds of different things to worry about with "balance" and there's all kinds of different meaning to the word itself as in mechanical and power delivery from the crank and such and the counter effects on said block it's "prying" off of...

Pauls drawing seems to put the crank through stresses very similar to an inline 4 banger,,, but they don't seem to have a problem holding together at over 16,000 rpms on the smaller ones...

here's a wiki link that does cover allot of the stuff that is not as obvious

https://en.wikipedia.org/wiki/Engine_balance

A.K. Boomer
10-03-2015, 06:55 PM
I wondered if those two cylinders could be on the same axis with only the connecting rods being displaced to the sides of those pistons. Probably increase the wear on the knuckle pins.

You could do that but it would have no effect on the crank/rocking effect that will still be evident at TDC and BDC - and also think for the most part create strange wear patterns on bearings and such along with creating "flexy" rods "sideways" and all kinds of unwanted problemo's

dp
10-03-2015, 07:32 PM
Well it wasn't until you brought it up. For no known reason in the universe.

It was a response to Paul's out of the blue post. I just showed a simple reconfiguration used by VW, Porche, Subaru, Lycoming, and Continental. They're not too concerned about vibration but are very worried about crank breakage. That was the curse of the Corvair. That, and cam shafts. Tell you what - make of list of things you think are on-topic in this thread so we don't have to go through this again.

Pickleforks can be on separate pins separated by a journal like any other kind of rod. It is easy to fabricate and assemble but can be something of a b*tch to align as anyone who has set up a Harley crank knows. Obviously not impossible, though, if you have a purpose-made jig.

Just so you know this is a design thread where ideas are introduced and discussed and the winners are applied to the OP's project. Nobody has the authority to dismiss anything.

A.K. Boomer
10-03-2015, 08:04 PM
this is why I was pushing Bri for the twin crank opposed twin,

that wiki link goes into the basic reason and the numbers give the meaning as to "why" in the link but this also explains the main reason too even without looking up what the numbers mean;

"A boxer engine is a type of flat engine in which each of a pair of opposing cylinders is on separate crank throws, offset at 180 to its partner, with 13. an evenly spaced firing. If the pistons could lie on the same crank rotational plane, then the design is inherently balanced for the momentum of the pistons. But since they cannot, the design, despite having a perfect 3. phase balance largely cancelling the non-sinusoidal imbalance, inherently has 4., 6., 14. and 16. imbalances due to the crank pin rotating planes being offset.[6]"

a gear to gear twin crank design would be the bomb...

brian Rupnow
10-03-2015, 08:26 PM
Jeez Guys---I'll just be happy if the darned thing runs!!! My plan is to have the two cylinders running on opposite cycles. When one piston is coming up to top dead center under compression stroke, the other is coming up to top dead center on exhaust stroke. That way I get a power pulse every 360 degrees of rotation.-----Brian

Rosco-P
10-03-2015, 08:55 PM
I shortened that base up as much as I could, and I flipped the toes of the angle frame to get my cylinder bases all on one surface. I like the proportions much better this way, although it will have to set up on a wooden base to get flywheel clearance. Dang, I like that flywheel!!!

Why not make the base "tall" enough to incorporate a flywheel pit, same as a real engine would have?
http://todengine.blogspot.com/

A.K. Boomer
10-03-2015, 09:12 PM
Jeez Guys---I'll just be happy if the darned thing runs!!! My plan is to have the two cylinders running on opposite cycles. When one piston is coming up to top dead center under compression stroke, the other is coming up to top dead center on exhaust stroke. That way I get a power pulse every 360 degrees of rotation.-----Brian

I know Bri - I know,,,
It's just not the first time Iv asked you for a twin crank two cylinder opposed and seeing as though you kick out a new engine every couple/three days I thought you might oblige this time --- I guess I got my feelings hurt again :-(

everybody else seems to always get what they want ( whimper whimper - whine whine) maybe monday after this ones built and your all rested again? thanks A.K.B.

J Tiers
10-03-2015, 10:26 PM
You could do that but it would have no effect on the crank/rocking effect that will still be evident at TDC and BDC - and also think for the most part create strange wear patterns on bearings and such along with creating "flexy" rods "sideways" and all kinds of unwanted problemo's

It does work though, and "most" of the masses are then opposed, pistons, plus a certain amount of the rods, but obviously not the big end. They run smoothly when made that way.

A.K. Boomer
10-04-2015, 01:00 AM
JT, if im understanding this correctly --- you still have fore and aft crank journals do you not?

in that case that's all I need to know, the forces will still be exerted on said journals and "crank rock" will occur or more appropriately put #4 of the wiki link;
4. Plane balance - e.g. Boxer Twin pistons travel on two different rotational planes of the crankshaft, which creates forces to rock the engine on Z-axis

in my opinion yes you may be reducing in certain area's but you are playing with fire in so many ways.

loads of friction from rod flexing in ways they are not designed for - therefor cocking bearings and such --- pistons dragging sideways! limited RPM's due to it snowballing out of control - now there goes your main reason for trying to achieve good balance --- it's a clusterfuqe of compromises across the board, just run a typical Boxer and your way ahead of the game, want to get "perfect" run a gear to gear twin crank..

A.K. Boomer
10-04-2015, 01:49 AM
Check out this config.

im not sure about balance with this design as much as mine,

but this is interesting --- twin crank alright --- but looks like zero piston skirt drag would be achieved with this unique design...

and yes you could keep pistons on same plane - but not that it would matter because they are not in 180 degree's dynamic sync with each other...

https://s.yimg.com/fz/api/res/1.2/Lic.sJ4xPI0chqtKR0GPwA--/YXBwaWQ9c3JjaGRkO2g9NzgyO3E9OTU7dz0xMjgw/http://media.caranddriver.com/images/10q4/370718/lanchester-twin-crank-twin-schematic-photo-370766-s-1280x782.jpg

brian Rupnow
10-04-2015, 08:14 AM
A.K.Boomer---i know it's not going to salve your injured feelings any----but---I honestly did consider a twin crank design before settling on something a bit more conventional. I think it would be really neat too. Just more work than I wanted to tackle.--Brian

J Tiers
10-04-2015, 09:22 AM
Worked perfectly for a 1925 2hp 2cycle boat motor. Would work here too. Sorry you hate it so much, but you will have to have a seance to tell the designers how much it wouldn't work.

A.K. Boomer
10-04-2015, 10:02 AM
Brian Im just razzin ya :)
I actually have to thank you for what you do - showing your builds as you go and listening to input both good and bad along the way, and most importantly your "shoot from the hip" build techniques that evolve right before our very eyes,

it's for all of the above that you are a great credit to this place...

You take me back to my teens where my brain used to live - it was my favorite obsession to draw up new plans almost daily and ponder how they would work,,, the possibilities are endless and it's a great brainteaser exercise to do...

speaking of, Now I am intrigued by this other twin crank design due to there being no piston skirt drag - this really is a unique little beast and at first glance I did not like having to have the pistons not dynamically oppose each other and having to leave things all up to the counterweights ---------- counterweights can only work so well due to the fact that they shake the engine when not needed - when the piston is approximately half way down the bore on one stroke and again to the opposite side when going half way up,

but take a look at this little beast again --- it will not do that - the counterweights cancel each other out perfectly in this mode yet build together towards the TDC and BDC of each piston and they do it progressively ---

https://s.yimg.com/fz/api/res/1.2/Lic.sJ4xPI0chqtKR0GPwA--/YXBwaWQ9c3JjaGRkO2g9NzgyO3E9OTU7dz0xMjgw/http://media.caranddriver.com/images/10q4/370718/lanchester-twin-crank-twin-schematic-photo-370766-s-1280x782.jpg

this is why balancer shafts can work so well in the big singles - classic example - the KLR 650, note the balancer chain arrangement to mimic gear to gear to achieve opposite rotating direction of the balancer shafts - taking off on the outer part of the chain from the crank to drive it, exactly what you need to do to help cancel the massive crank counterweights that are on these engines when the the piston is at it's half bore mark, yet the balancer shafts will line up and help when needed at TDC and BDC; http://ckmcgraw.com/afmcgraw/klr_files/balancer2.jpg

trouble with conventional B.S. is they take precious energies to run,,,

that's why im liking that twin crank design, although im sure with all those components there is more initial drag to begin with keep in mind your eliminating piston skirt drag and that's a biggie... this engine has it's very own opposite rotating balancer shafts built right into the cranks... it's ingenious to say the least...

A.K. Boomer
10-04-2015, 10:14 AM
Worked perfectly for a 1925 2hp 2cycle boat motor. Would work here too. Sorry you hate it so much, but you will have to have a seance to tell the designers how much it wouldn't work.

In 1925 people also thought smoking cigarettes was good for you --- people have moved on - well the intelligent ones anyways...

you can build all kinds of things that will "run" --- there's even cult like followings with present day stuff like that being sold today (ugh ughm) still does not make it "right" - if your end goal is building the best performance/dependability/practicality trust me - that "thing" misses the mark by a mile... in fact I will flat out say it - it's an engineering NO-NO....

A.K. Boomer
10-04-2015, 10:22 AM
More on the Lanchester Twin Crank twin


http://www.autoneuroticfixation.com/2012/03/odd-engineering-lanchester-twin.html

Get this --- a 4000cc twin that they are calling "smooth running"

that would be something to see, this guy was ahead of his time....

brian Rupnow
10-04-2015, 10:23 AM
I resorted to a little hocus pocus when I designed the bushings for the crankshaft and camshaft. I wanted to be able to pull the crankshaft or the camshaft straight out of the engine without splitting those two main frame angles. So---I have a large "bushing insert" with the bushing pressed into it, bolted into a counterbore in the frame angle which supports the end of the crankshaft closest to the flywheel. If I remove the flywheel and the blue "bushing insert" the entire crankshaft should pull straight out through the side of the housing. I did something very similar at the opposite end of the camshaft, only there the bushing itself has a large enough outer diameter that by unbolting it and pulling it out, the whole assembled camshaft can be pulled out thru the side of the main frame.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OPPOSED%20PISTON%20CROSS%20SECTION._zpsq8ahpuo1.jp g (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OPPOSED%20PISTON%20CROSS%20SECTION._zpsq8ahpuo1.jp g.html)

A.K. Boomer
10-04-2015, 10:34 AM
More totally astonishing facts,,,

get this ---- this thing could rap out to 12,500 rpms !!! that's two 2 liter pistons cranking out those kinda RPM's !

talk about balance --- the average cut off point for an in-line 4 cylinder to run without balancer shafts is just two liters - half the size, and you will be lucky to also spin it at half the RPM's

crazy, this is back in 1900, what could be done with todays materials and machining?

Lanchester Twin-Crank Twin

Produced in 1900 in England, this air-cooled, 4.0-liter-flat-twin engine featured a twin-crankshaft in which one of the twin cranks was positioned above the over cranks with each piston on the engine featuring three connecting rods. One heavy rod was then positioned in the centre with two lighter rods positioned on the outside, with the two lighter weight rods connected to one crank and the heavy rods directed to the other crank.

The final result of this rather oddly-designed engine was 10.5 HP with a 12,250 RPM capability. Even more amazing, the engine had relatively little vibration. Unfortunately, the Lanchester Twin-Crank Twin engine was only produced for four years, with manufacturing ending on the model in 1904.

J Tiers
10-04-2015, 01:47 PM
In 1925 people also thought smoking cigarettes was good for you --- people have moved on - well the intelligent ones anyways...

you can build all kinds of things that will "run" --- there's even cult like followings with present day stuff like that being sold today (ugh ughm) still does not make it "right" - if your end goal is building the best performance/dependability/practicality trust me - that "thing" misses the mark by a mile... in fact I will flat out say it - it's an engineering NO-NO....

We know you have opinions, that you consider to be facts...... Supported with heavily-loaded statements that are not really germane......And a certain amount of attempted "board-bullying".

It's a flipping model engine here..... not for a locomotive with a guaranteed MTBF. And your opinions don't really count. I am not inserting an opinion, just the fact that it was made, worked nicely for its purpose, and there are some STILL working almost 100 years later, so there is a good likelihood it will work here. I saw them working on boats in the 1950s and 1960s, up in N Minnesota, not being babied. And it is an interesting construction that could be fun to make.

As for opinions, the only opinion that counts here is Mr Rupnow's. The rest of us are making suggestions.

A.K. Boomer
10-04-2015, 01:59 PM
it's all good JT --- im just adding my two cents too, "it's a flipping model engine here" just did not seem to be quite your attitude when debating the finer details with DP but whatever - no worries...

but for real here, can you believe the RPM specs of the two liter per piston twin crank lanchester ?

if not a misprint it really is incredible don't you think?

CarlByrns
10-04-2015, 05:37 PM
More totally astonishing facts,,,

get this ---- this thing could rap out to 12,500 rpms !!! that's two 2 liter pistons cranking out those kinda RPM's !

talk about balance --- the average cut off point for an in-line 4 cylinder to run without balancer shafts is just two liters - half the size, and you will be lucky to also spin it at half the RPM's

crazy, this is back in 1900, what could be done with todays materials and machining?

Lanchester Twin-Crank Twin

Produced in 1900 in England, this air-cooled, 4.0-liter-flat-twin engine featured a twin-crankshaft in which one of the twin cranks was positioned above the over cranks with each piston on the engine featuring three connecting rods. One heavy rod was then positioned in the centre with two lighter rods positioned on the outside, with the two lighter weight rods connected to one crank and the heavy rods directed to the other crank.

The final result of this rather oddly-designed engine was 10.5 HP with a 12,250 RPM capability. Even more amazing, the engine had relatively little vibration. Unfortunately, the Lanchester Twin-Crank Twin engine was only produced for four years, with manufacturing ending on the model in 1904.

I think there is a bit of Edwardian-era advertising here. Can you cite a source of the engine actually running at 12,250 rpm as opposed to being capable of being powered by an outside source to 12K rpm with injury.

I don't believe there was a Pre WWI mag or trembler coil (remember, the Kettering system was far in the future) ignition system capable of that kind of precision in 1900. Even today's F1 engines top out at 15K and they use digital electronics to get the sparks delivered on time.

A.K. Boomer
10-04-2015, 06:39 PM
I too find it hard to believe --- it's a crazy amount of RPM for that size engine and and esp. the era, im thinking misprint,

still - many of the other engine fact on this sight seem to be correct

https://www.tyreright.com.au/sidewall/blog/general/2015/january/22/7-unusual-car-engines


but here's the specs for the pre-twin crank single cylinder around 1896 - only 1,000 rpms -- much more down to earth...

http://uniquecarsandparts.com/lost_marques_lanchester.htm

im betting the misprint is a digit off and maybe 1,250 rpms is more like it - those are massive pistons coupled to huge stroke...

A.K. Boomer
10-04-2015, 06:56 PM
this link is more to do with displacement - no specs on RPM's although they did develop their own type of ignition system unique in it's day.

http://www.autoneuroticfixation.com/2012/03/odd-engineering-lanchester-twin.html

A.K. Boomer
10-04-2015, 07:04 PM
Confirmed --- this site gives all the facts - 4 liter opposed twin and only 1250 rpm,

while you had a tough time accepting the ignition source that was capable of those kinds of numbers I did have a tough time accepting the mechanical aspect of it... that is of course why it was blowing my mind,,,

still - claims of smooth running all the way up to it's 1250 rpm "redline" are said in most all articles

http://www.msn.com/en-us/autos/research/the-10-most-unusual-engines-of-all-time/ss-BBjVjSa#image=8

A.K. Boomer
10-04-2015, 07:12 PM
this is the bogus link --- https://www.tyreright.com.au/sidewall/blog/general/2015/january/22/7-unusual-car-engines

brian Rupnow
10-04-2015, 07:15 PM
Well, noooo---We don't really know what we're doing.--But--we're having fun. Gotta have some way to get fuel into those cylinders.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsyimqrchl.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsyimqrchl.jpg.html)

dp
10-04-2015, 07:45 PM
Any technical reason the plumbing has to cross like that? I don't imagine the valves need to be different sizes for something like this, so the heads could be mirror images. Cam lobes would need to be cut accordingly, of course. If the exhaust were the farthest from the flywheel they could easily be routed down and into a collector exhaust.

Edit:
Ok - going to say it :) You are poised to build a very cool manifold/still-air box for a crank case cover that you can surface mount your carburetor on. That would have a lot of cool factor.

A.K. Boomer
10-04-2015, 07:52 PM
are you talking the VW type intake manifold?



I bet it's almost straight across with the built in offset and the valves of the heads automatically swapping sides...

I believe the heads are already mirror images are they not? even if the valves are of different size... ?

dp
10-04-2015, 08:01 PM
I'm thinking more like Edelbrock hogged out of aircraft billet with a rounded endmill :)

Regarding the heads that's what I was thinking. The external plumbing is arranged diagonal. And come to think of it, driving both an exhaust and an intake valve from the same cam lobe requires symmetric valve timing for in/out and that is rarely done.

NM - I see he's got separate lobes for each valve.

brian Rupnow
10-04-2015, 08:48 PM
Well, actually---it was trick photography.----at least it was trick positioning of the model in that last view posted. The intake and exhaust valves, ports, etcetera on both cylinders are exactly the same. Right now, as seen in the model, both cylinders and attachments are identical. When I was establishing the offset between the two opposing cylinders, I wasn't even thinking about the intake manifold, other than that I would eventually need one. The carburetor is an existing model, based on the carburetor that Malcolm Stride designed for his twin engine Jaguar model engine. I imported that carburetor model into this overall model, positioned it parallel to the faces of the frame, took a rude guess at how high I wanted it to set above the frame sections, then lined it up with the intake port of one cylinder and "froze" it there. Then I modeled the intake runner for that side. As you can see in this true orthographic top view, I just copied that first intake runner and "posed' it in the approximate position it would have to be in to feed the other cylinder. There are two ways to do 3D modeling. One is called "bottom up", whereby you create each part individually, then pull them into an "assembly file" and mate them to one another to create an accurate assembly. I use that method a lot. The second way to do 3D modeling is called "top down". In it, you have an assembly made from dozens or even hundreds of individual parts all mated together and 'fixed" in 3D space. I can use the faces or features of the existing models to create sketches which I turn into new models based on the existing stuff, right in the assembly file.. That is how I modeled the carburetor support, and the first intake runner, because they both run between already existing models---i.e. the carburetor is in a fixed position (remember, I "froze" it there) The top of the angle frame which the carburetor support runs to was already there, and the short intake pipe on the cylinder was already there. This intake system is a "first shot" kind of thing. I still have to model in a fuel tank and position it correctly in relationship to the carburetor, then decide what kind of supports I need for the fuel tank. The cam lobes are actually modeled and fabricated as individual pieces that slide over the plain 'camshaft" and Loctited into final position. (It really does hold). I can arrange the individual cam lobes in any manner I want, even to make the engine run clockwise or counter-clockwise.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsnugpft1z.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsnugpft1z.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OPPOSED%20PISTON%20camS.C._zps1hh7sov7.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OPPOSED%20PISTON%20camS.C._zps1hh7sov7.jpg.html)

dp
10-04-2015, 09:31 PM
The overhead projection says a lot. The picklefork rod and 45 v-twin design of Harley eliminates a lot of parts. That might have been a consideration in the early 1900's but today it's part of the Harley mystique if you're a fan, or obsolete engineering if not. I'd forgotten how far offset the Honda and Yamaha v-twin cylinders are because of having separate crank pins. Harley finally did add counter-balance shafts into some of the v-twin engines to reduce vibration. The way you notice the difference is the flashing red light in the mirror on a balanced engine is almost impossible to see because it's just a red dot. Not the case at all with the unbalanced engines where a flashing red light will fill the mirror :)

I was stopped at a light one day while riding my Harley Road King. The engine is mounted in flex joints and when idling the heads move fore and aft about 1.5". The rear exhaust mounts are slip joints because they're moving like crazy, too. A kid in a car next to me asked why my engine was rocking like that and the answer was "It's a Harley".

A.K. Boomer
10-04-2015, 10:17 PM
DP Harley gave the smooth steeds with dependable cooling to the guys in the military --- as it should be :-)

http://i261.photobucket.com/albums/ii52/Diecastduck/Harley%20Davidson%20Museum/DSCF9050.jpg

CarlByrns
10-05-2015, 12:09 AM
Confirmed --- this site gives all the facts - 4 liter opposed twin and only 1250 rpm,

while you had a tough time accepting the ignition source that was capable of those kinds of numbers I did have a tough time accepting the mechanical aspect of it... that is of course why it was blowing my mind,,,


Actually, the mechanical speed was almost believable because of the balanced design and because the Victorian/Edwardian engineers were fearless. Some of the early steam turbines on cream separators whizzed up past 20K rpm without any fancy X-rays or Magnaflux QC inspection. Go or blow testing.

Willy
10-05-2015, 12:39 AM
A Harley dual-fire coil is reasonably priced.

http://www.ebay.com/itm/DUAL-FIRE-IGNITION-COIL-FOR-HARLEY-DAVIDSON-BIG-TWIN-AND-SPORTSTER-MODELS-/121769975216?hash=item1c5a0e5db0&vxp=mtr




Alright!!--I'm convinced. a dual Harley coil it will be. Thanks DP.


Brian, just going over your build thread and noticed what must have been a slight oversight on DP's part when recommending the dual fire HD coil in in his Ebay link. This coil is intended to be used with an electronic ignition module. Point triggered HD dual fire coils look and function identically to the one in the link but have a primary resistance of 5 ohms instead of the 2.9/3 ohm electronic ignition triggered coils.

I mention this because due to the higher current draw of the electronic ignition coils, point life will suffer. I know that it is not recommended to use these coils with point triggered systems but not knowing the duration in hours of run time you expect from this system it may or may not be a factor.

If you have not yet ordered this coil I'm sure that supplier will be able to source you the correct 5 ohm coil.

Below is a source for one from a supplier in Ontario. I know the price is higher but I'm sure you are more than aware that the US Ebay price without shipping is not an actual "landed on Brian's doorstep" price.:)

http://www.strictlyvtwin.com/eshopprod_cat_8916-63862_product_1653712.DRAG_SPECIALTIES_IGNITION_CO ILS.htm

A.K. Boomer
10-05-2015, 08:50 AM
Actually, the mechanical speed was almost believable because of the balanced design and because the Victorian/Edwardian engineers were fearless. Some of the early steam turbines on cream separators whizzed up past 20K rpm without any fancy X-rays or Magnaflux QC inspection. Go or blow testing.


I hear what your saying but turbines and LARGE pistons are two different things, I guess I kinda got caught up in the hoopla of the double rod mechanisms potentially adding a ton of strength and also the fact that the pistons could be kept very light and small due to not having to worry about skirt drag and side loads...

Still - by todays standards 4 liters is a fair sized V/6 in autos and trucks and they only rap out at 5 or 6,000 RPM's

doubling those kinda R's in a 4 liter twin (or a 12 liter 6!) is a pretty big feat and I personally do not know of anything even today that can, if you do let me know would be interested in checking into it...

Check out this patent on a double crank, he crosses the rods, having the cranks off to the sides like this creates incredible variations between piston speeds and degree of flywheel travel between things like comparing compression stroke to power stroke, could be yet another tool to match up burn rates better for RPM's that are lower or higher depending what your looking for in an engine and which way you rotate it and time your valves ---- also some possible testimony of just how much you could possibly widdle away at piston size;
http://www.google.com/patents/US5595147

these engines are very interesting to me in all kinds of ways - I was thinking stacking the cranks in-line and NOT using counterweights due to there not being a need for them because each piston and upper rod will cancel each other out perfectly from being dynamically 180 degree's opposed,

but my design would not be as compact and is conventional for piston size skirts and such,
I like Lanchesters - if your going to put on a freak show you might as well go all out :p

A.K. Boomer
10-05-2015, 09:08 AM
Bri your engine is starting to look very cool and I like that large flywheel/fan not only for aesthetics but for function, that little bugger should cool well and also have some momentum storage,

that much mass hanging that far out on the crank WILL help reduce the initial "crank rock" vibrations that we were all pondering --- but im curious about something, will it further reduce the effect the faster it rotates?

I ask this of course due to the gyroscopic effect - every time Iv spun a bike wheel and then tried to throw it off with its axles the resistance is incredible although it then does manifest itself into another strange motion...


but what kind of effect if one was rocking back and forth multiple times a second while it's rotating? better than just stationary weight ? or could it set up some strange "oscillation" patterns at certain RPM's ?

brian Rupnow
10-05-2015, 09:25 AM
I'm thinking that makes a rather nice fuel tank. It is 1" o.d. x 3 1/2" long. It is supported off the carburetor bracket. (Don't ask me exactly how yet), and the top of it is about 1/4" below the center of the carburetor barrel. It does clear the flywheel.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpshvzyafvo.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpshvzyafvo.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsftpdfenq.jpg (http://s307.photobucket.com/user/BrianRupnow/media/CONTINUATION%20OF%20MAIN%20ALBUM1/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpsftpdfenq.jpg.html)

A.K. Boomer
10-05-2015, 09:28 AM
You have to have gravity feed don't you?

brian Rupnow
10-05-2015, 09:37 AM
No, if it had gravity feed all of the fuel would run down into the cylinders or flood out onto the engine thru the air horn causing a fire hazard. There is no float and needle in these carburetors to act as a shut-off. There is enough venturi effect from the inrushing air thru the air horn to lift the fuel 1 to 2" from the tank. Sometimes you have to put a ball check valve in the line so it won't let the fuel bleed back down into the tank at low rpm..

A.K. Boomer
10-05-2015, 09:43 AM
Got it - like the old briggs "vacujet" carbs,,, run a little rich with a full tank -- run a little lean with a low one, but worked pretty well and did not varnish up as much with drying out fuel inside the float bowl...

old mart
10-05-2015, 10:42 AM
The problems of lubricating the big end bearings should be addressed before cutting any metal, unless the engine is designed to run for thirty seconds or less. The design seems to require oil feeds from both ends. There is an alternative, I once had a Honda 50 pushrod engine with a horizontal cylinder which had an oil scoop forged into the big end for wet sump. The downside of this is that the Honda had a roller bearing big end which required minimum lubrication.

brian Rupnow
10-05-2015, 01:34 PM
Old Mart--these engines will run for hours with just a shot of lube from a squirt oil-can. Remember--It is a MODEL engine. It will never, in it's life cycle run under heavy or sustained load for long periods of time. It will very seldom see high RPM's. These are a "demonstration" engine. I have many open crankshaft hit and miss horizontal engines that set and run four hours at a time at low speeds, and the big end of the con rod doesn't even get hot. If this was to be an Honest to God real working engine driving a pump or a saw or some piece of industrial equipment, then you would be absolutely correct.

old mart
10-05-2015, 04:59 PM
Well, that saves a lot extra design headaches, and a little oil in the fuel would take care of cylinder and valve lubrication.

brian Rupnow
10-05-2015, 07:27 PM
Well, that saves a lot extra design headaches, and a little oil in the fuel would take care of cylinder and valve lubrication.

I run a Viton o-ring on these engines instead of a cast iron piston ring. That gives a better seal, and requires no "break-in" to wear in the ring for a good seal. It also requires running a small amount of oil in the fuel, to keep the Viton ring lubricated.

brian Rupnow
10-07-2015, 08:10 AM
A slight change to the "magic flywheel". I have noticed at my metal supplier that they frequently have offcut "donuts" of 660 bronze. This one measures 4.1" o.d. x 2.76" i.d. z 1.1" thick. The 3" square piece of aluminum is also an offcut. I get offcuts for half the price of new material, because they don't charge for a mans time to pull material out to the saw and cut it off. The bronze will of course be the main weight of the flywheel rim. The aluminum will be set up in my 4 jaw and turned to become the center hub. The brass bar will become the "vanes". I haven't got the material for the outer band yet, but it will probably be thin wall steel tubing.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OPPOSED%20PISTON%20FAN%20FLYWHEELS.C._zps5jt8w0il. jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OPPOSED%20PISTON%20FAN%20FLYWHEELS.C._zps5jt8w0il. jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/FLYWHEEL%20MATERIAL%20001_zpsogj538zr.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/FLYWHEEL%20MATERIAL%20001_zpsogj538zr.jpg.html)

brian Rupnow
10-07-2015, 01:55 PM
I don't plan on boring you to death with a thousand pictures of "How to build a flywheel.", but this rim has a special place of honour.--It is the very first piece ever made on my new lathe.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/FLYWHEEL%20RIM%20001_zps7qdnq9a5.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/FLYWHEEL%20RIM%20001_zps7qdnq9a5.jpg.html)

brian Rupnow
10-09-2015, 05:17 PM
I chickened on the flywheel center material. A 1" long slice of 3" round aluminum stock was only $5 and the 1" long outer rim part was $5. I will save the 3" square piece of aluminum and use it for something else.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/FLYWHEEL%20MATERIAL%20001_zpsoj2wprsk.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/FLYWHEEL%20MATERIAL%20001_zpsoj2wprsk.jpg.html)

brian Rupnow
10-10-2015, 12:54 PM
New lathe is performing very well. I am as nervous as a cat in a roomfull of dogs while running it, but it has performed every task very well. I stalled it this morning taking trepanning cuts on the center of a flywheel. It didn't like that very much, ---Just stopped turning and gave a very angry hum. I hit the e-stop, backed out the tool and started the lathe again. No harm, no foul.--scared me though!!! The trepanned recess is 1/4" deep. I tried to plunge the full depth in one shot just to see if I could.--I couldn't. So plunged .100 deep closet to the center, then plunged .100 deep closest to the rim, then used crossfeed to move back and forth between the two annular grooves taking .010" deep cuts until I had a flat bottomed recess, then plunged 0.100' again at inner and outer extents, repeated the back and forth, then a final plunge of 0.050" and travel back and forth removing .010" on each cut until I ended up with a flat bottomed 1/4" deep recess.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/TREPANNING%20A%20FLYWHEEL%20001_zpsckhsmpwl.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/TREPANNING%20A%20FLYWHEEL%20001_zpsckhsmpwl.jpg.ht ml)

brian Rupnow
10-11-2015, 09:29 AM
The flywheel center is finished except for keyway and set screws. I am going to try my hand at heat shrinking the bronze outer rim onto the aluminum center. I have only .003 to .004" interference, and could most likely press it in cold. Mrs Rupnow wouldn't take very kindly to me heating up the bronze ring in the kitchen oven, so I will leave it under my big heat light overnight and keep the aluminum center in the freezer overnight and see what happens. I'm not ready to assemble them yet. I have some very strange and devious things to do to that bronze ring with my milling machine and rotary table to prepare it for the eight cooling vanes, and I need to leave the center open to grip with the 3 jaw chuck fingers on my rotary table.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/FLYWHEEL%20CENTER%20FINISHED%20002_zpsn4eu6tgb.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/FLYWHEEL%20CENTER%20FINISHED%20002_zpsn4eu6tgb.jpg .html)

J Tiers
10-11-2015, 11:19 AM
You don't need the oven, you can use a top burner, or a regular propane torch. Either is much faster than the oven, and you can still use a contact temperature probe, or a temperature crayon, etc

brian Rupnow
10-11-2015, 06:13 PM
This vaned flywheel is getting more and more interesting. I'm kind of making it up as I go along. I'm pretty sure I can set the rotary table at 45 degrees to the long axis of the table, mount the bronze ring on the 3 jaw chuck holding it from the inside and using a 3/16" endmill run the table back and forth in X axis to cut the slots 3/16" wide x 1/8" deep. Then drill and tap the two #2-56 holes in the bottom of the slot.--Then rotate the rotary table 45 degrees and repeat---eight times in total. The vanes would be from 3/16" x 7/8" flatbar, drilled and counterbored for #2-56 socket head capscrews. The end of the flatbar closest to the center would just be a flat 90 degree cut. The cut at the other end however, will take on a strange twisted shape if it is going to be full contact with the inside of the outer rim. They will be brass, so MAYBE I can cut them .050" long, then bolt them to the bronze hub, press in the center, and then take a skim cut on the outer ends of the flatbar with the lathe to bring them down to final size.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/ASSEMBLY%20OF%20VANED%20FLYWHEEL_zpsisdyml3v.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/ASSEMBLY%20OF%20VANED%20FLYWHEEL_zpsisdyml3v.jpg.h tml)

Rosco-P
10-11-2015, 06:40 PM
Why don't you just weld the vanes in place?

brian Rupnow
10-11-2015, 07:36 PM
Too much distortion and welds not all that accessible for cleanup after the fact.--The yellow ring is 660 bronze. Right now I have two or three i.c. engines I have built and posted on this forum about that run either small plastic fans or fabricated brass fans, driven by an o-ring drive off the flywheel. I have my heart set on this "pretty" version, but it may not happen. I can see my way clearly up to the point where I have to attach the outer rim. That is problematic. I may make up everything but the outer rim. That would create a dangerous finger chopper, But--If I ran it in a close fitting "fixed" shroud it would still have the same effect in terms of creating airflow over the cylinders, be safe in terms of chopped fingers, and be one heck of a lot easier to fabricate.

brian Rupnow
10-11-2015, 08:53 PM
Okay---Maybe I'm onto something a little more realistic. The flywheel with vanes revolves--the outer rim has become a fixed shroud. Much, much easier to fabricate.--Finger safe, and still provides cooling air.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpswidonbk8.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zpswidonbk8.jpg.html)

ulav8r
10-11-2015, 09:51 PM
Attached shroud vs. fixed shroud should be determined by the mass needed for smooth running and balance.

dp
10-12-2015, 12:15 AM
Okay---Maybe I'm onto something a little more realistic. The flywheel with vanes revolves--the outer rim has become a fixed shroud. Much, much easier to fabricate.--Finger safe, and still provides cooling air.


Bonus coolness points if you put the vanes on your rotab and use your mill to carve them into airfoils.

old mart
10-12-2015, 11:25 AM
The advantage of an attached shroud on the fan if the motor is small is that it could be used to start the engine if there were no sharp edges.

A.K. Boomer
10-12-2015, 11:34 AM
Bonus coolness points if you put the vanes on your rotab and use your mill to carve them into airfoils.

I was thinking it would be kinda cool to take the vane material as a long unit before cutting and place one end in a vise, then clamp and twist the other end - then cut them all up and install them with the progressive pitch towards the center more as it's slower speed and needs it to match the outer radius that needs to be at a less radical angle...

Toolguy
10-12-2015, 11:39 AM
Anything is easy if someone else has to do it!:)

dp
10-12-2015, 12:33 PM
I was thinking it would be kinda cool to take the vane material as a long unit before cutting and place one end in a vise, then clamp and twist the other end - then cut them all up and install them with the progressive pitch towards the center more as it's slower speed and needs it to match the outer radius that needs to be at a less radical angle...

Like a one-turn screw thread? That would be interesting. Wonder how effective it would be. Of course vanes can be carved directly onto the flywheel perimeter which is not difficult to set up using a spindexer and a rotab - assumes one's mill has enough head room.

A.K. Boomer
10-12-2015, 01:12 PM
not that radical - just mild as it's not that great of a change in radius,

this Porsche 917 fan has the effect if you look for it, blades pitch is more towards center of the hub and tapers off a little at the ends...

https://farm3.staticflickr.com/2554/3803774736_84022cc2d3_z.jpg


I was just thinking how easy it might be if he was starting with a strip of material and was going to cut it all up for vanes anyways, would be easy to get a fairly uniform bend throughout it's length so they all would match,
although holding it to cut after the fact might be a bit of a hat trick...

RWO
10-12-2015, 03:29 PM
I have to ask. Why not just use a model airplane propeller. Then you have a way to determine your engine's output power and also it will cool the cylinders quite well. The usual model engine running on a display stand with no connected load proves only that it has enough power to overcome its own internal friction. Screw that. An engine has to be able to produce usable power or it's just the maker's wet dream .

RWO

A.K. Boomer
10-12-2015, 03:43 PM
it's duel purpose - it's first and foremost a flywheel - Brians just utilizing it to help cool too



albeit his latest version does have less flywheel effect because he's dropping the outer ring and it's what would have had most kinetic energy storage per weight than any other part of it...

Duffy
10-12-2015, 04:25 PM
Brian, rather than those difficult 2-56 screws through the length of each vane, why not locktite the vanes into the hub and slip the rim/shroud over the whole unit? It you HAVE to drill and tap, then two 2-56 shcs in the ends of the vanes through the shroud will lock everything up. Be a LOT easier I think.

J Tiers
10-12-2015, 05:29 PM
Dovetail them in place. If a fir tree shape works for jet engines, a plain dovetail will work for this, and you get to make a little cutter (just like Steve Acker did) as well. Pin in place.

Don't like that? Then cut slots in the wheel at an angle off a true radius, cut angled bases on the vanes, and setscrew or pin them to prevent sliding axially. If it was good enough for the Germans in WW2, it's good enough for you.

A.K. Boomer
10-12-2015, 05:52 PM
Dovetail them in place. If a fir tree shape works for jet engines, a plain dovetail will work for this, and you get to make a little cutter (just like Steve Acker did) as well. Pin in place.




would that not take some trick machining? I mean starting fore and ending aft of the flywheel whilst traveling around it too? and then matching the vanes to fit???

I don't think Brian has that kinda equipment... ??? I know I don't.

unless your talking straight across and just dig in deep in the middle? hmmm

dp
10-12-2015, 06:31 PM
A simple thing is to use a sheet metal disk with cut and bent vanes on it which is then attached to the flywheel.

brian Rupnow
10-12-2015, 07:27 PM
Making it up as I go along---the rotary table mounted at 45 degrees to the X axis on the mill and a 1/8" four flute endmill did the job just as I hoped it would. The slots are 3/16" deep x about .130" wide. While in the same set-up I drilled 1/16" holes thru on center of each slot. I then Loctited 1/16" cold rolled round rod x 1" long into the holes, with 1/2" exposed. I made up the 8 "vanes" from 1/8" thick aluminum and drilled a blind 1/16" hole 0.7" deep in the center of each "vane". I knew that the .125" vanes were not going to fit tightly into the 0.130" wide slots----but I had a plan. After trial fitting everything, I got out my old friend J.B. Weld, mixed up a batch, and filled one groove at a time and coated the exposed portion of 1/16" cold rolled, then tapped the vane into place until it was seated. Right now the bronze ring and the aluminum hub are both 1/8" wider than the planned 3/4" finish width. It is my greatest hope that after Loctiting/pressing the aluminum hub into the bronze ring (I have decided not to use heat shrinking) that I will be able to grind a really sharp tool and face both sides of the aluminum center, the bronze ring, and the sides of the vanes without everything turning to crap.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/FAB%20BLADES%20INSTALLED%20001_zpsspevpnmh.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/FAB%20BLADES%20INSTALLED%20001_zpsspevpnmh.jpg.htm l)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/FAB%20BLADES%20INSTALLED%20002_zpswg2dutlj.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/FAB%20BLADES%20INSTALLED%20002_zpswg2dutlj.jpg.htm l)

Toolguy
10-12-2015, 08:03 PM
I predict it will work.:)

brian Rupnow
10-12-2015, 08:17 PM
I predict it will work.:)

I hope you are right. I would have felt better about it if I had some .062 music wire instead of the cold rolled, but ya use what ya got!!

Black Forest
10-13-2015, 06:52 AM
Brian might I suggest that the first time you fire this engine up you have another person do it for you. But you be there with the video camera! What comes to mind are the throwing stars from Bruce Lee!

brian Rupnow
10-13-2015, 08:17 AM
My intent was to get a large hose clamp at the hardware store and snug it up around the outer diameter of the fins before I started to take the cuts. As far as fins flying out, that was the purpose of the 1/16" dowels inserted half into the bronze and half into the vanes and coated with either Loctite on the bronze end and JB Weld at the vane end. There is a close fitting metal shroud completely surrounding the flywheel and vanes. I don't think anything is going to fly apart.---Brian

michigan doug
10-13-2015, 09:20 AM
It's not like it will be running at 8,000 rpm. It will work fine.

J Tiers
10-13-2015, 10:21 AM
looked like your pins are radial????

I figured you would drill them in axially, or at an angle, so they went through the vane crosswise and the centrifugal force put them in shear. At low rpm and diameter, likely no issue, but.....

brian Rupnow
10-13-2015, 06:55 PM
Here we are at the lumpy nasty stage. The vanes are secured with a large pipe clamp. The aluminum hub is a "Damn that's close/Loctite fit". After a night of curing, it will be into the lathe and either be the "Oh Wow--Look how good I am" stage or the "Oh Poop!! Start over again" stage.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/FLYWHEEL-LUMPY%20NASTY%20002_zpsgf7p8eg2.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/FLYWHEEL-LUMPY%20NASTY%20002_zpsgf7p8eg2.jpg.html)

RichR
10-13-2015, 09:18 PM
Hi Brian
Just wondering, why don't you put on the outer ring prior to taking your facing cuts?

A.K. Boomer
10-14-2015, 12:31 AM
Brain what's goin on with #2 fin? little drill bit wandering? u wanna talk about it? don't you just luv all the armchair quarterbacks?

Thanks for putting up with us Bri... :)

brian Rupnow
10-14-2015, 11:13 AM
Machining of flywheel with vanes attached went very well. The vanes never gave any indication that they might want to come off. The biggest challenge I had was that 660 bronze hub wanting to suck the tool into the work while facing it. I am putting this down to the fact that the shaft everything was mounted on was only 3/8" diameter, and once the tool tried to suck into the bronze the shaft would deflect a bit, then spring back, leaving a series of evenly spaced divots around the face of the bronze. I tried every machine speed and tool angle and sharpness, but nothing made any difference. Thankfully the divots were shallow enough to mostly come out with some 160 and 220 grit emery cloth. The aluminum vanes of course came out razor sharp, but some light file work knocked the sharp down a bit. I definitely won't be running this flywheel without a full surround shroud.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/FLYWHEEL-FAN%20FINISHED%20001_zpsxdsnl986.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/FLYWHEEL-FAN%20FINISHED%20001_zpsxdsnl986.jpg.html)

dp
10-14-2015, 08:15 PM
Turning it on a faceplate would probably have been a good idea. Spindly arbors do just you saw.

brian Rupnow
10-14-2015, 09:09 PM
Dp---I never even thought of that. It might have been difficult though. the fins actually stuck out past the face of the bronze. I suppose I could have used a spacer but honestly, I never even thought of it.---Good call!!!---Brian

brian Rupnow
10-14-2015, 09:12 PM
Brain what's goin on with #2 fin? little drill bit wandering? u wanna talk about it? don't you just luv all the armchair quarterbacks?

Thanks for putting up with us Bri... :)

A.K.---when I went to drill those holes, I found that I only had two 1/16" drills. One was duller than a hoe, and the other was worse. I didn't want to drive across town to the machinery dealer, so I went with what I had.---Shoulda known---

A.K. Boomer
10-14-2015, 09:51 PM
Oh well blades are flat, put em in a machinist vise and clamp to restore then a light buffing nobody will know,

have to admit the flywheel is looking pretty styling :)

brian Rupnow
10-15-2015, 08:23 AM
Now that, my friends, is a piece of angle!! I had to go across town yesterday to pick up some Destaco clamps for a customer project, and one of my metal suppliers is almost next door. I stopped in and asked if he had any offcuts of aluminum angles with 1/2" thick legs. He answered "Yes, and I've been saving it just for you!!!"---It is a piece of aluminum angle 8" x 8" x 1/2" x 10" long. Far more than I need, but there is a lot of good 1/2" material that I can salvage from it after I cut out what I need for the engine frame.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/ANGLE%20FOR%20TWIN%20OPPOSED%20FRAME%20001_zpsdqk3 utna.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/ANGLE%20FOR%20TWIN%20OPPOSED%20FRAME%20001_zpsdqk3 utna.jpg.html)

Duffy
10-15-2015, 11:09 AM
Brian that is a PERFECT example of a piece that is a candidate for table saw reduction!:)

brian Rupnow
10-19-2015, 08:53 PM
I haven't abandoned this project.--It's just that I've been so busy with other projects----. Tonight I stole an hour to add all the bolt holes into the two main frame angles and show the four 1/4"-20 bolts (green-two each side) that hold the angles together.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zps6pzxzapn.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/OVERALL%20ASSEMBLY%20OF%20OPPOSED%20TWO%20CYLINDER %20ENGINES.C._zps6pzxzapn.jpg.html)

brian Rupnow
10-23-2015, 04:33 PM
After a summer of "relative" idleness, my business commitments have exploded to the point where I have no time to build my own stuff!!! I did steal some time this afternoon to walk out to my converted bandsaw with that HUGE chunk of aluminum angle, and reduce it to smaller pieces, close to what my engine's finished frame size will be.This great flurry of real work will only last for a couple of months and then die down just before Christmas. After the struggle I had unloading and setting up my new lathe by myself, I decided to call a local machinery moving company and ask for a quote to move my old lathe out from my machine shop into my big garage, and move my new larger lathe from my big garage through my office into my small machine shop. They quoted $500 which seems like a lot, but I think some of the money from my current "real work" would be well spent having them do this. Both lathes are quite top heavy, and if I tipped either of them over while moving them, that $500 wouldn't seem like very much!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/frame%20rough%20cut%20001_zpstlf8gaj8.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/frame%20rough%20cut%20001_zpstlf8gaj8.jpg.html)

brian Rupnow
10-24-2015, 08:52 AM
This morning I have made the unsettling discovery that aluminum angles aren't really 90 degrees on the outside. In fact over a 2 1/2" leg. they run out as much as .030". I can clean this up, it's not a deal breaker, just a surprise. I wonder how much things will spring out of square when I machine away that rolled in inner radius? I think I will get rid of the inner radius first, see where things spring to, then clean up the squareness.

Lew Hartswick
10-24-2015, 09:46 AM
I was "exposed" to that by the machine shop foreman about 40 years ago. :-) I think he called it "Architectural angle" or some such. He then
proceeded to machine the outside square for me and it has stayed that way. I "think" the kind that has a sharp inside corner may be a bit
better in that respect. When I have to start with the radiused inside corner stuff I machine both inside and outside to make it square.
...lew...

J Tiers
10-24-2015, 02:39 PM
The rounded inside corner means it is "structural" angle. Architectural has the sharp corner, and may have a tighter spec on the included angle. Somewhere I used to have a PDF of the specs from one of the extruders, but I think it got lost.

brian Rupnow
10-24-2015, 04:16 PM
So there we have it. An absolutely fabulous way to spend a Saturday. The frame pieces are cut to size, the radius is machined away, and the main frame bolts and dowel pins are in place.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/GRAME%20BOLTED%20TOGETHER%20003_zps6yfwo5rj.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/GRAME%20BOLTED%20TOGETHER%20003_zps6yfwo5rj.jpg.ht ml)

sasquatch
10-24-2015, 04:22 PM
Nice Brian, and i too just discovered the same this past spring.

brian Rupnow
10-29-2015, 03:54 PM
Yes, Me darlin's---Any progress is better than "dead in the water"!! I got hung up this afternoon waiting for information from a customer, so I spent my time making the big "bolt-on" crankshaft bushing and drilling/reaming/boring the engine housing to fit it. Don't take me to task to heavily for the finish on that big bolt on bushing. It was machined from a piece of "mystery metal" with a carbide cutting tool of dubious origin. (I was given a big handful of brazed carbide tooling by a fab shop that has switched over to carbide inserts.)---it isn't going to be visible anyways, as it hides behind my finned flywheel when all is assembled. I have a jar of oilite bushings left over from something, and that is what you see pressed into the center of the bolt on bushing. No, that isn't the crankshaft you see setting in there---It's just a short piece of 3/8" rod to make a better picture.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/BOLT-IN%20CRANKSHAFT%20BUSHING%20DONE%20001_zpshgubm2xd .jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/BOLT-IN%20CRANKSHAFT%20BUSHING%20DONE%20001_zpshgubm2xd .jpg.html)

brian Rupnow
10-30-2015, 05:05 PM
On the side of the frame opposite to the bolt in crankshaft bushing, I also wanted to have a "bolt in" camshaft bushing, large enough to let me pull the assembled camshaft out through the side of the frame. This results in some rather interesting milling, (than God for my DRO's). The sheet of paper laying in the background shows a model of what the cam bushing will look like. ----(scale is larger than the real deal, but it shows up better). The through hole in the frame is reamed to 0.5" diameter and the protrusion on the far side of the cam bushing will be 0.499" diameter. The reamed hole in the center of the red cam bushing is .375" diameter to match the outer diameter of the oilite bronze camshaft bushing. The odd shaped cavity in the frame will be clearance all around for the outer perimeter of the cam bushing, and the cam bushing will be held in place by two #8 shcs.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/HOLE%20FOR%20CAM%20BUSHING%20IN%20FRAME%20001_zpsa vohhboh.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/HOLE%20FOR%20CAM%20BUSHING%20IN%20FRAME%20001_zpsa vohhboh.jpg.html)

A.K. Boomer
10-30-2015, 05:46 PM
Im liking that fan and all the other work - but I think your milling head might need a "re-tram" :)

at this rate it should be up and running sometime next month? or is that pushing it a bit? still lots of small parts to build I guess.

brian Rupnow
10-30-2015, 06:29 PM
A.K.--You could be right about the milling head. I bought the mill new 5 months ago and I have never checked it for tram. I have been very busy with customer "stuff" and so my own projects have to wait. I have found one thing out for sure. When I was just doing pure "design" work, I had lots of energy for machining my own projects. The last few months I have been into a bunch of "design and build" for a customer, doing a lot of jig and fixture work. By the end of my normal 8 hour day, I'm not nearly so ready to rush into my shop and start whittling on my own stuff!!!-----Brian

Black Forest
10-31-2015, 04:38 AM
A.K.--You could be right about the milling head. I bought the mill new 5 months ago and I have never checked it for tram. I have been very busy with customer "stuff" and so my own projects have to wait. I have found one thing out for sure. When I was just doing pure "design" work, I had lots of energy for machining my own projects. The last few months I have been into a bunch of "design and build" for a customer, doing a lot of jig and fixture work. By the end of my normal 8 hour day, I'm not nearly so ready to rush into my shop and start whittling on my own stuff!!!-----Brian

Brian I can relate to that bigtime! Maybe we are having a midlife crisis. I will be 64 in April and though my head is going full time will all I have to do and manage my body is telling me I ain't a kid anymore. The energy levels are just not there that used to be. Granted I don't exercise as much but damn I get tired fast lately.

brian Rupnow
11-01-2015, 10:24 AM
A.K. BOOMER--You were right. I made up a holder for my test indicator and the head was out of tram by .006" in the x axis. I was able to being it back to "o" without a lot of aggravation. It is also out of tram by .0025 in the Y axis, but there isn't any easy way to adjust that so I will just live with it.---Brian

brian Rupnow
11-04-2015, 04:30 PM
This has to be one of the busier pieces I have made. (Actually, it's two pieces bolted and doweled together). It has: 30 tapped holes, 4 clearance holes, 21 reamed holes, one bored hole, and one counterbored pocket. I THINK they are all in the right place. I have been very busy with design work, moving lathes, and repositioning electrical outlets and the associated drywall work to accommodate the new lathe in my tiny machine shop. The old green 10" x 18 BusyBee lathe and all its attachments has been sold and taken away to a new home in Toronto.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/FRAME%20FINISHED%20001_zpsb6mkl6of.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/FRAME%20FINISHED%20001_zpsb6mkl6of.jpg.html)

Toolguy
11-04-2015, 05:17 PM
I may be looking at this wrong, but it seems the overlap of the joints is 90 degrees to the model in post 61. It may pose a problem for assembly and/or disassembly with dowel pins in the overlap parts. Just wondering.

brian Rupnow
11-04-2015, 05:45 PM
I don't plan on ever taking it apart. The crankshaft and the camshaft can be installed through the side of the frame. Hindsight being 20/20, if I had to do this over again, I would probably make it from a cube of aluminum. The only issue would have been cleaning out the rad in the four inside corners.

Willy
11-04-2015, 07:28 PM
.......................
The old green 10" x 18 BusyBee lathe and all its attachments has been sold and taken away to a new home in Toronto.


I hope you got a good price for it Brian, it certainly has a well documented history of being a capable machine!
The new owner need look no further than the pages of the HSM forum for verification:).

brian Rupnow
11-05-2015, 09:37 AM
Willy--I got $1000 for it. It was up on our local buy and sell for a week with no offers. I had it listed high at $1300, thinking I could come down to a $1000 offer. I finally posted it in the Toronto buy and sell and had a buyer withing two days who offered me $1000 and I didn't quibble..---Brian

brian Rupnow
11-05-2015, 12:23 PM
Out with the old----In with the new!!! The new CX701 lathe is installed in my machine shop ready for action. I had to relocate one electrical outlet and repair a bit of drywall, but other than that everything went very well. I have a piece of 2" x 1/8" mild steel bar welded into a U shape. It bolts to the studding in the wall and both ends are bolted to the cabinet which supports the lathe. The lathe is bolted through the catch pan and through the top sheet metal of the supporting cabinets. This just gives me that extra bit of security so I know that the lathe and stand is not going to ever fall over.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/NEW%20LATHE%20IN%20MACHINE%20SHOP%2005-NOV-2015%20001_zps0w9pougm.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/NEW%20LATHE%20IN%20MACHINE%20SHOP%2005-NOV-2015%20001_zps0w9pougm.jpg.html)

Lew Hartswick
11-05-2015, 06:29 PM
Does that new lathe have a power cross feed?
...lew...

brian Rupnow
11-05-2015, 06:42 PM
Yes Lew, it does. Power longitudinal feed and crossfeed. It has no clutch though, so the power feeds are kind of scary to use. You know that if you are turning or facing to a shoulder and overshoot, it's going to break something.---Brian

Stepside
11-05-2015, 07:28 PM
Brian

If you still have the "old machine", you could use a "Sharpie" and put the dates of ownership and your signature somewhere on the back or underneath. No real reason beyond memories and old times sake.

Pete

brian Rupnow
11-05-2015, 08:31 PM
The old machine is gone, sold a few days ago. It served me quite faithfully since 2008, but it was time for me to "move up" a bit from a starter lathe. I sincerely hope that the fellow who bought it from me gets as much enjoyment from it as I did.----Brian

brian Rupnow
11-11-2015, 12:34 PM
One cylinder machined this morning.--One more to go this afternoon!!! They are cast iron, not aluminum with a liner.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/FIRST%20CYLINDER%20DONE%20001_zpscsxbio4s.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/FIRST%20CYLINDER%20DONE%20001_zpscsxbio4s.jpg.html )

brian Rupnow
11-11-2015, 03:20 PM
As my old father-in-law used to say "It ain't perfect, but it's damned close!!!" This project has been stalled for so long, I just had to take some time to do something for ME for a change. Today while I was working on the cylinders, another order for more "fixtures" came in so I know what I'll be doing the rest of the week, and it isn't working on my engine. It is very interesting to actually do some work on my new lathe. It is miles different from my older smaller lathe, and I will have to work with it quite a lot before I become comfortable with it. I did use the power feed to bring the cast iron down to correct diameter, and it certainly leaves a beautiful finish.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow025/BOTH%20CYLINDERS%20DONE%20001_zps9bjop6am.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow025/BOTH%20CYLINDERS%20DONE%20001_zps9bjop6am.jpg.html )

Norman Bain
11-11-2015, 03:31 PM
.... It has no clutch though, so the power feeds are kind of scary to use. You know that if you are turning or facing to a shoulder and overshoot, it's going to break something.---Brian

Am I correct is assuming that you are engaging the power feed; then starting the spindle motor?

I do not know the lathe make/model at all but by the look of the controls you should be able to start spindle without the power feed engaged; then engage the power feed to start the cut. Likewise at end of cut there should not be need to attempt to idle down the spindle to stop at shoulder etc; just disengage the power feed.

Apologies if I have misunderstood.

Cheers,
Norman

brian Rupnow
11-11-2015, 04:14 PM
Norman--I can engage or disengage the power feed at any time with the lever on the front of the apron. That still doesn't make me all warm and fuzzy about the potential of running the tool against a shoulder and potentially breaking the lathe and costing me a ton of money.---Brian

10KPete
11-11-2015, 07:51 PM
Brian, I can remember back about 45 years ago when I first started using a lathe with power feeds. Scared me half the death
the thought of crashing. But, by paying very close attention and not allowing myself to be distracted by other goings on around
me I one day realized that I was comfortable with power feed. That's when I really had to apply the discipline so as to not
become too complacent!!! To this day I watch any power feed on a tool like a freeking hawk!! But I use it all the time. Just
stop a bit short of the shoulder and creep in in by hand.

Pete

brian Rupnow
11-11-2015, 08:04 PM
Pete--I expect that with enough time, I will get to the same point.

EddyCurr
11-11-2015, 08:32 PM
That still doesn't make me all warm and fuzzy about the potential of running the tool against a shoulder and potentially breaking the lathe and costing me a ton of money.---BrianToolguy posted the following guidence in CX701 Lathe Report (post #62). I do not
recall seeing an acknowledgement from you - perhaps you did not notice his post ...


You never want to power feed right to the end. Power feed to a comfortable distance from your target (a shoulder, a solid stop, indicator reading, etc.) then disengage the feed and move the last 1/8" or whatever is left with the large handwheel on the apron. If you try to use power right to the end, you will have problems. Same for facing. Power off early, then use the crossfeed handwheel to sneak up to the finish point.

For getting length what I did before I had a lathe with DRO was to cut to a point I knew was short, set a stop or indicator on the ways against the carriage, measure the cut part, then move in the difference towards the chuck. A micrometer carriage stop works nicely for this. You can even make your own with a cheap eBay Starrett or Mitutoyo mike head. Those go for $20 - $40 all the time.

brian Rupnow
11-12-2015, 08:49 AM
Yes Eddy, I did see that.---Brian

Willy
11-12-2015, 09:47 AM
Pete--I expect that with enough time, I will get to the same point.

Brian's got it it, just a new discipline to take heed of. No different than when first learning to drive, don't pay attention there and the crash can result in a fatality. You soon learn to stay focused.

Well most of us I hope!

brian Rupnow
11-12-2015, 10:14 AM
I suspect that I am going to have to break down and buy a 2 axis DRO for this lathe. The power feed is great, but unless you have a DRO, you have no really good way to see how far you've travelled.

brian Rupnow
11-25-2015, 02:21 PM
After what seems like an amazingly long time I finally got some time today to do a bit more work on my engine. I drilled all the clearance holes in the flanges which attach the cylinders to the "block" and installed the bolts. Everything bolted up the way I expected it to, and then I drilled the 10 holes (five in each cylinder) that get tapped #5-40 to hold the cylinder heads onto the cylinders. When I was tapping the eighth hole, the tap broke off at full depth flush with the top of the cylinder. --This caused a great deal of dismay as you can well expect, but after picking away at it for a while with no success, I chucked up a 1/16" carbide endmill and was able to mill out the tap and save the cylinder. I have a length of "stress proof" 1144 steel to make a one piece crankshaft from, and will probably make that my next order of business.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/CYLINDERS%20TAPPED%20004_zpsrhjkygih.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/CYLINDERS%20TAPPED%20004_zpsrhjkygih.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/CYLINDERS%20TAPPED%20005_zpsnntcermd.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/CYLINDERS%20TAPPED%20005_zpsnntcermd.jpg.html)

brian Rupnow
11-26-2015, 03:02 PM
Today was "crankshaft madness day" at my house!! I wanted to buy a piece of 1 3/8" 1144 stress-proof to make my crankshaft from. 1144 is not available to buy in bars, only rounds.--and my supplier only had it in 1 1/2" diameter. The first two pictures show me reducing the stock from 1 1/2" diameter to 1.3" final diameter.--And yes, I did use the power feed for this operation, with an HSS cutter at 550 rpm. Also, in the same set-ups I put in the 60 degree countersink in each end so I can eventually turn the crankshaft between centers.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/CRANKSHAFT%20MADNESS-1%20001_zpswotqlw7h.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/CRANKSHAFT%20MADNESS-1%20001_zpswotqlw7h.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/CRANKSHAFT%20MADNESS-1%20002_zps2173edab.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/CRANKSHAFT%20MADNESS-1%20002_zps2173edab.jpg.html)

brian Rupnow
11-26-2015, 03:11 PM
After turning the piece to 1.300" finished diameter, I had to get it from a round into a flat. I thought of various ways to cut away most of the slab from each side on my bandsaw, but any good way was going to involve me building some kind of fixture, so I decided to mill the excess material away. My thoughts in using the rotary table chuck to hold the part for this machining operation, along with the tailstock, was that this was probably the set-up that gave me the best hope of getting flat parallel surfaces and being able to flip the part over a true 180 degrees to machine the second side away. It worked, but at a .015" depth of cut there was a LOT of cranking involved. I have cut the blank to be 3/4" longer than the finished length of the crankshaft, so I figured I would probably be safe in holding 3/16" of the piece in the chuck on the rotary table, mounted on my mill.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/CRANKSHAFT%20MADNESS-1%20004_zpskfbgrmfl.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/CRANKSHAFT%20MADNESS-1%20004_zpskfbgrmfl.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/CRANKSHAFT%20MADNESS-1%20005_zpsxloivdjy.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/CRANKSHAFT%20MADNESS-1%20005_zpsxloivdjy.jpg.html)

brian Rupnow
11-26-2015, 03:15 PM
All of the preceding operations have brought me to the point where I may actually be able to start machining the crankshaft. The first operation will be to put in two more countersunk holes in each end to provide a spot for turning the crank "throws" between centers.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/CRANKSHAFT%20MADNESS-1%20009_zpssibr2xh6.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/CRANKSHAFT%20MADNESS-1%20009_zpssibr2xh6.jpg.html)

brian Rupnow
11-28-2015, 10:10 AM
Since I distinctly remember making a beautiful one piece crankshaft a few years ago between centers, and then discovering to my horror that the lathe tailstock was way out of alignment, I thought some checking was in order. The lathe tailstock "as delivered" from the factory was out---not much, but not dead nuts either. I did a google search last night and discovered a Youtube video of aligning the tailstock with a co-axial indicator. This morning I set things up as shown in the video, and adjusted my tailstock side to side as close to zero indicator reading as I could get it. Now before anybody jumps on me with both feet, I know this doesn't truly align the spindles. However it does align the rotating centerline of the chuck with the centerline of the tailstock spindle. The TIR of the chuck is very little.--It will be close enough to accomplish what I am planning to do.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/check%20tailstock%20alignment%20001_zpss5hjrm8c.jp g (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/check%20tailstock%20alignment%20001_zpss5hjrm8c.jp g.html)

dp
11-28-2015, 01:50 PM
I've done the same with that very indicator, Brian, and it's always worked great. You can also spin it on the tapered sides of a center. This is particularly handy if you use a boring head on your tail stock with the intention of turning a taper as it lets you zero the head's feed screw before dialing in the offset.

10KPete
11-28-2015, 02:05 PM
Different indicator, but that's exactly how I check my tail stock.

Pete

brian Rupnow
11-28-2015, 03:41 PM
Some days, I wish I had taken up a different hobby in my semi-retirement, say NEEDLEPOINT or something like that!!! I've fought with that damned tailstock all day. I get is set so it's perfect indicating on the pointed end of a dead center. Then I try indicating it on the barrel i.d. and it shows out of center. I correct it to almost perfect, then indicate on the outside diameter of the barrel and it's out of center again. Finally after burning up a whole day, I put a brand new dead center in, made sure it was seated properly, then set it again.

Toolguy
11-28-2015, 03:45 PM
The OD and ID may not be concentric to each other?

Willy
11-28-2015, 03:56 PM
The OD and ID may not be concentric to each other?


This or perhaps the barrel was extended and or the lock lever was re-positioned on your OD reading?

brian Rupnow
11-28-2015, 04:08 PM
Something is definitely not kosher, and I don't know what right now. After getting everything set up to be "perfect" as indicated, I chucked up a piece of 5/8" cold rolled round bar which had a good, concentric point turned on the end of it. I slid the tailstock with a dead center in it forward until the twp points were almost touching. There was a visible difference of at least 0.030" horizontally when viewed from directly above. Then I looked at the "witness marks" on the rear of the tailstock, and they weren't even close to being lined up. Maybe I should have left "well enough" alone instead of getting into this. I will try to borrow a "test bar" from a local machine shop on Monday to see if I can use it to set things properly.--At least doing this operation with a "test bar" it will truly be supported on the center of the spindle on a dead center, not the chuck.

Toolguy
11-28-2015, 04:18 PM
You can do the same thing with your 3 jaw chuck. Put one end of the 5/8" bar in the chuck and other end on the dead center in the tailstock. The center for the tailstock can be done by dialing in the bar on the 4 jaw and center drilled. Chuck the bar only 1/4" in so the chuck can't put a side load on the bar.

Put a dial indicator on the carriage with the plunger on the side of the bar and find the high and low readings. Turn the chuck so the bar is halfway between high and low. This compensates for the runout of the 3 jaw chuck. The bar may be dialed in with the 4 jaw if preferred.

Move down to the tailstock end of the bar and get the same indicator reading there by moving the tailstock sideways. Then your part will be parallel to the ways.

RichR
11-28-2015, 09:35 PM
Hi Brian
Chuck up a piece of aluminum. Take a skim cut to true it to the spindle. Face the end and center drill it. Part off a slice close to the end
you center drilled. Place your center in the tailstock and use it to hold the piece you sliced off against the piece in the chuck. Now
adjust the tailstock until the two pieces line up. You can use an indicator or just feel where the two pieces meet with your fingers or
a fingernail.

dp
11-28-2015, 09:45 PM
That trick works pretty well and results only in a small sacrificial cutoff as waste. Here's Frank Ford's illustrated how-to guide: http://www.frets.com/HomeShopTech/QuickTricks/TailstockAlignment/tailstockalignment.html

JCHannum
11-28-2015, 10:17 PM
Since you are going to be turning between centers, drill centers in the ends of a piece of stock about the same length as the intended crankshaft and set up between centers as you intend to set up the crank.

Take a cut the length of the piece and check for taper. Adjust the tailstock accordingly until taper is removed. Once the T/S is adjusted, lock it in place and leave it there until done, using the handwheel and barrel to remove and replace the workpiece.

brian Rupnow
11-29-2015, 06:54 PM
Today I removed the chuck and mounted the faceplate on my new lathe, put the dead center in the headstock spindle, and made a couple of discoveries. First discovery was that the two lathe dogs I bought 6 years ago with my first lathe and never actually used, won't work with my new faceplate. Second discovery was that although I bought a "live center" when I bought the lathe a few months ago, it has dissapeared. In fact I don't ever remember seeing it since I bought the lathe. Of course, this raises the question, ---Did I ever actually get one and bring it home? (It is on the invoice which I still have.) ---or---Did I pay for it but it was temporarily out of stock and they were going to order it in from Toronto for me. I will talk to the Barrie store tomorrow and see what they know. I've had so much machinery coming and going around here in the past six months that almost anything is possible. I still haven't totally sussed out my tailstock alignment, but have decided that if I am going to do this right, I might as well do it between centers, and since I plan on machining the crankshaft between centers anyways now was a good time to get the faceplate mounted and to take the four jaw chuck out of the packing box and make sure it was okay. I keep my shop and garage fairly well organized---It is very unusual for me to misplace a piece of tooling. It is especially suspicious when I never remember even seeing the live center. I will build a couple of "custom fit" lathe dogs this week to work with the crankshaft.

brian Rupnow
11-30-2015, 10:43 AM
It looks like the first order of the day will be to make up a couple of "custom" lathe dogs to use when making the crankshaft between centers. These will be welded up from some scraps out of my steel "odds and ends" pile and saved as "future tooling".
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/LATHE%20DOG%20FOR%20RECT.%20CRANKSHAFT_zps9ddu3q5r .jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/LATHE%20DOG%20FOR%20RECT.%20CRANKSHAFT_zps9ddu3q5r .jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/LATHE%20DOG%20FOR%20.375%20INCH%20SHAFT_zpsqodbosp 3.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/LATHE%20DOG%20FOR%20.375%20INCH%20SHAFT_zpsqodbosp 3.jpg.html)

brian Rupnow
12-02-2015, 11:53 AM
After what seemed to be far more struggle than I anticipated, the tailstock alignment is correct within .001" of being the same as the center in the headstock spindle. I ended up machining two ends of a bar held between centers and adjusting the tailstock until I was getting micrometer readings within .001" of each other at each end, and said "That's it!!!". I made a lathe dog to drive the bar that was held between centers, and was really surprised how much it threw the lathe out of balance. I would have liked to run the lathe at 800 rpm to get a really good finish on the two areas I turned, but at anything over 350 rpm the lathe wanted to levitate. I will have to add counterweights to the faceplate when I turn the crankshaft between centers using a lathe dog.

EddyCurr
12-02-2015, 12:21 PM
I made a lathe dog to drive the bar that was held between centers,
and was really surprised how much it threw the lathe out of balance. I would have
liked to run the lathe at 800 rpm to get a really good finish on the two areas I turned,
but at anything over 350 rpm the lathe wanted to levitate. I will have to add counterweights
to the faceplate when I turn the crankshaft between centers using a lathe dog.Can you add some lightness to your lathe dog?

As illustrated, the design looks unusually heavy for the intended purpose.
A hollow pin and pockets or holes along the lever arm would reduce the
amount of imbalance.

Does it need to be single-sided, or is it feasible to extend the dog outward
on the opposing side? Extending out both directions would/could cancel
virtually any imbalance attributable to the dog.

.

JCHannum
12-02-2015, 01:02 PM
Did you run the lathe without the dog to see if the imbalance was due to the dog or in the dogplate/faceplate?

EddyCurr
12-02-2015, 01:08 PM
Let's suppose Mr Rupnow's set-up creates an imbalance of
1/2 lb located 6" out from the machine axis.

It seems to me as though for a speed of 350 RPM (18.3 SF/sec),
there would be a centripetal force of around 10.5 lbs or 46.5 N.

For a speed of 800 RPM (41.88 SF/sec), I estimate centripetal
force would be in the order of 54.6 lbs or 242.6 N.

Perhaps an engineer could review this layperson's figures.

.

brian Rupnow
12-02-2015, 01:47 PM
EDIT--EDIT---EDIT---The faceplate itself is NOT very well balanced, contrary to what I first posted. at 400 rpm with just the faceplate on the spindle, I am getting noticable vibration in the lathe.

brian Rupnow
12-02-2015, 04:10 PM
Okay--we forge onward here, adding to our list of what seems to work and what doesn't. I now know that the 4 jaw chuck is complete and does indeed fit the spindle. The faceplate is a beautiful thing, and it fits alright, but it throws the lathe out of balance at anything over 400 rpm., even without any lathe dog. I take it from that that the faceplate casting itself is out of balance. Changing the 3 jaw chuck (which does seem to be in balance) for the faceplate (which seems to NOT be in balance) is a pain in the arse!!!! I now see the wisdom in just chucking up a piece of roundstock and turning a 60 degree point on it to make a center at the headstock when I want to turn something between centers. Doing this will allow me to use a much shorter, and therefore more balanced lathe dog as well.

10KPete
12-02-2015, 05:08 PM
Brian,
I use the three jaw/drive dog set-up whenever possible for the reasons you've stated. I only use the face/drive plate
when the chuck would be in the way.
Pete

EddyCurr
12-02-2015, 05:08 PM
Determine where the faceplate is heavy and by how much,
then mark location. (A fixture for balancing grinding wheels
will be useful for this task and serve well in its intended role
going forward.)

Use the existing shop-made lathe dog with the FP by positioning
the LD opposite the heavy side of the FP.

One could just balance the FP, but many set-ups will be lop
-sided. As long as the FP's imbalance wgt & location is known,
then less counter-weight ought to be necessary to balance the
assembly.

.

EddyCurr
12-02-2015, 05:44 PM
Harold Hall displays a dedicated shop-made tool for
balancing faceplate set-ups off the lathe that would
an improvement over my previous suggestion

http://homews.co.uk/page151.html

There are several other pages on his site discussing FP
work, here is one example

http://www.homews.co.uk/page544.html

It might be interesting to poll members asking for their
advice regarding speed considerations when turning faceplate
and between-center work pieces.

.

kf2qd
12-02-2015, 06:35 PM
You ought to check your faceplate and see if it has any sppeed limit printed or cast into it.

brian Rupnow
12-02-2015, 07:00 PM
So---Maybe a lathe dog with a more balanced approach---
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/CHUCK%20CRANKSHAFT%20AND%20LATHE%20DOG_zpsb2ow8xum .jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/CHUCK%20CRANKSHAFT%20AND%20LATHE%20DOG_zpsb2ow8xum .jpg.html)

Toolguy
12-02-2015, 07:44 PM
That one should work like a champ!:) You might want to scribe a center line on it to line up with the center point in the chuck.

10KPete
12-02-2015, 07:48 PM
That one is great!!!

Pete

RichR
12-02-2015, 10:49 PM
So---Maybe a lathe dog with a more balanced approach---
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/CHUCK%20CRANKSHAFT%20AND%20LATHE%20DOG_zpsb2ow8xum .jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/CHUCK%20CRANKSHAFT%20AND%20LATHE%20DOG_zpsb2ow8xum .jpg.html)

That balances the dog, but don't you also need to compensate for the piece you are turning? It's off balance too.

dp
12-03-2015, 12:10 AM
That balances the dog, but don't you also need to compensate for the piece you are turning? It's off balance too.

I can't imagine balance is going to be anywhere near the problem the interrupted cut on that slab is going to be. High speed isn't needed to get a good finish. Unless the metal is some horrid thing like 1018, and even then, high speed only gets the misery over with sooner.

RichR
12-03-2015, 01:55 AM
The interrupted cut could be minimized by roughing most of the unneeded material away on the mill.

dp
12-03-2015, 02:46 AM
The interrupted cut could be minimized by roughing most of the unneeded material away on the mill.

True - just going by the CAD drawings that don't indicate a band saw was employed.

brian Rupnow
12-03-2015, 05:38 PM
And here we have the latest in "Extreme low tech lathe doggery". Drill and tap one leg of a very cheap machinist clamp for a quarter inch bolt. The designer liked his fancy design, but the machinist said `Whoa---Too much work!!!` I will put a tie-wrap around the shaft and thru the arms of the machinist clamp `just in case`.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/LOW%20TECH%20LATHE%20DOG%20005_zpsxdgvbdck.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/LOW%20TECH%20LATHE%20DOG%20005_zpsxdgvbdck.jpg.htm l)

A.K. Boomer
12-03-2015, 05:52 PM
That one should work like a champ!:) You might want to scribe a center line on it to line up with the center point in the chuck.

yeah - or somebodys gonna die lol scribing a center line may just mean one more mark on the forehead lol

I guess if the RPM's are kept low enough anythings possible... looks like it's underway so keep us posted Bri and thumbs up for "hanging it out there" a little :)

brian Rupnow
12-03-2015, 06:51 PM
Well---Maybe it's not up there with sky-diving, but it sure makes my old heart go "pitter-patter"!!!! I'm running at 200 rpm.--Standing well to one side of potential "flying bits". First rod journal is cut to correct width but needs a clean-up to get the diameter down from 0.430 to 0.375". Probably nothing to it for all the "old time machinists" out there, but it scares the Bejeezuz out of me.

Toolguy
12-03-2015, 09:47 PM
It is better to stay a little scared and safe than complacent and chomped. You have to always maintain a certain amount of respect for these machines, even the smaller ones can bite pretty hard.

brian Rupnow
12-04-2015, 08:32 PM
Tomorrow morning I get to the "extreme breath holding" part of this----The "sides" of the rod journal are turned to their finished width, but I have to turn the journal diameter down to it's finished size. On my old lathe, I would have set up my "carriage stops" on both limits of travel to keep the sides of the crankshaft from whacking the top of the parting tool and creating instant disaster. On my new lathe, I don't have any real good way of setting up "travel limiters" on the topslide (Which I have set up parallel to the ways and can still thankfully advance by hand.) This will be a "Stand well to one side and move the topslide REALLY SLOWLY" sort of deal.

brian Rupnow
12-05-2015, 11:59 AM
Here we have finished rod journal #2. Everything is right on spec. and turned to final size. I have a "perfectly fitted" aluminum spacer in the gap where I cut the first journal from, to keep the crank from deforming under the pressure of the lathe "centers". It is held in place with glue from a glue gun---See---I do learn things from these forums!!! This second journal wasn't quite as scary as the first one, but you certainly don't want to let your mind wander while doing it!!! It really helps my peace of mind knowing that I actually do have a carriage lock on this lathe. (Which I just found out about this morning when I logged on and read my forum mail.) I will now glue a spacer in this new gap and then proceed to find my way through turning the ends down.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/journal%202%20turned%20001_zpshxkviset.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/journal%202%20turned%20001_zpshxkviset.jpg.html)

brian Rupnow
12-06-2015, 12:13 PM
This morning I turned the first main crankshaft journal, and discovered a dirty little secret. I have suspected all along that it would be almost impossible to set the topslide perfectly parallel to the ways. You can get it super close with a dial indicator, but I still didn't totally trust it. I confirmed that this morning by turning the crankshaft journal down over it's full 2" length using the topslide only, with the carriage locked, but I left the journal a bit oversize. I then measured both ends with a micrometer, and sure enough, I was turning a very slight taper. Having established that, I locked the topslide and used the power feed on the carriage to take the last .025" off the diameter, to final size. That left a very nice finish, and no taper. We learn---we learn---
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/FIRST%20CRANK%20JOURNAL%20DONE%20002_zps9hscxnos.j pg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/FIRST%20CRANK%20JOURNAL%20DONE%20002_zps9hscxnos.j pg.html)

brian Rupnow
12-06-2015, 09:26 PM
So---Here we have it, finished except for trimming the ends to get rid of the countersinks, and a keyway for the flywheel. It fits into the "engine block" just like it's supposed to. That 1144 stress-proof steel is a wonderful material. After all the machining operations involved, I put the shorter end of the crankshaft in the three jaw chuck on my lathe and put an indicator on the very far unsupported end, then rotated the chuck through 360 degrees. The total indicated runout was .003"!!! That is .0015" of "center shift". Almost unbelievable. Not only did I manage to make a nice crankshaft, but I learned some good things about using my new lathe. I'm glad it's done. I have sweat bullets this week.---Brian
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/CRANKSHAFT%20FINISHED-2%20001_zpsztm8lsbo.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/CRANKSHAFT%20FINISHED-2%20001_zpsztm8lsbo.jpg.html)

Toolguy
12-07-2015, 09:46 AM
Beautiful piece of work. Looks great Brian!

michigan doug
12-07-2015, 02:05 PM
It's always exciting when it starts to look like an engine.

Is there a feature that controls end play so the crank doesn't grind on the inside of the case?

brian Rupnow
12-07-2015, 02:22 PM
It's always exciting when it starts to look like an engine.

Is there a feature that controls end play so the crank doesn't grind on the inside of the case?

Yes, the plan is that the oilite bronze bushings on each side of the "engine block" protrude about .015" into the inside of the block. this should give me all the clearance I need.

brian Rupnow
12-07-2015, 02:33 PM
I've reached the point in this build where I need a bit more stable platform to set things on as I add them. I didn't want to invest any more time/work until I was sure that I was going to be able to make the crankshaft. Now that it is finished, I will go ahead and build the engine baseplate. This is not going to be an "oil in the base" engine. Oil will be administered from the open top, via squirt can. The milled "catch basin" in the baseplate will catch any oil drips and guide them out thru a drain hole in the front of the baseplate. I will probably put a perimeter gasket between the "engine block" and the baseplate to keep oil from seeping out onto the surface of the baseplate..
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/BASEPLATE--OPPOSED%20TWINS.C._zpsodulymnd.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/BASEPLATE--OPPOSED%20TWINS.C._zpsodulymnd.jpg.html)

brian Rupnow
12-07-2015, 05:30 PM
And---we have a base. Not much to brag on here, because all the "features" are hidden inside the engine block. Still, it used up an entire afternoon, and it fits!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow026/BASE%20FOR%20ENGINE%20002_zpsaahgu6fx.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow026/BASE%20FOR%20ENGINE%20002_zpsaahgu6fx.jpg.html)

10KPete
12-07-2015, 08:29 PM
Heads! Pistons! More parts!! Wanna see it run!!:D:D:D

Lookin' great Brian.

Pete