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brian Rupnow
05-18-2015, 06:25 PM
A few years ago, Philip Duclos designed a rather homely (or so I thought) little engine with an oscillating cylinder, not unlike one of Elmer Verburg's steam powered "wobblers". The REALLY BIG difference was that this engine was gasoline powered.----and---It was a hit and miss engine---and it was air cooled. It was a very clever design, and according to Philip Duclos, it ran well. I want to build something different enough to be interesting, and to add my own personal touches to "pretty it up" a bit. I give Philip full credit here for his original design, and hope that wherever he may be now, that he smiles a bit when he sees what I am doing to his "Whatzit" engine.----Brian
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYLINDER%20ASSEMBLY-OSCILLATING-1_zps8pkij8e2.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYLINDER%20ASSEMBLY-OSCILLATING-1_zps8pkij8e2.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYLINDER%20ASSEMBLY-OSCILLATING-2_zpsvtbwlip1.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYLINDER%20ASSEMBLY-OSCILLATING-2_zpsvtbwlip1.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYLINDER%20ASSEMBLY-OSCILLATING-CROSS%20SECTION_zpsrrsmttox.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYLINDER%20ASSEMBLY-OSCILLATING-CROSS%20SECTION_zpsrrsmttox.jpg.html)

aostling
05-18-2015, 06:52 PM
Brian,

This looks like a fun project. The cylinder appears to oscillate about its center of mass, minimizing vibration. With no connecting rod the piston can have a long stroke, with minimal side-loading.

I look forward to getting more details as you proceed.

brian Rupnow
05-18-2015, 08:30 PM
I did a web search for "oscillating internal combustion engines", and didn't find any. Then I searched specifically for "Whatzit engine" (that was the name of the one Philip Duclos designed and built) and couldn't find anything. I think this will be a lot of fun. I seem to vaguely remember a write-up where somebody had built one but they couldn't keep the spark-plug wire from jumping off when the engine was running, so they installed a stationary "spark-post" very close to the moving sparkplug, and the spark jumped the gap to fire the plug in the oscillating engine.

aostling
05-18-2015, 09:42 PM
... they installed a stationary "spark-post" very close to the moving sparkplug, and the spark jumped the gap to fire the plug in the oscillating engine.

It's hard to overstate the entertainment value of such an engine, if it runs.

The oscillating cylinder with its cooling fins could be quite effective. I spent much of my career calculating convection heat transfer coefficients -- I feel safe in saying that there are no published formulas which pertain to this.

MrSleepy
05-19-2015, 05:00 AM
They are usually called "Free Piston Linear" motors/generators (either single or dual piston). Youtube has lots of videos of them.

Although yours has a tied end and is not strictly free .. its the same principle.

Rob

A.K. Boomer
05-19-2015, 10:56 AM
Found this example of a 3/D printed one.

going to be one rattling SOB with the weighted crank throws on the wrong side though :p

https://s.yimg.com/fz/api/res/1.2/5BDU4.INCwdNy5O6vvfFUg--/YXBwaWQ9c3JjaGRkO2g9NTMzO3E9OTU7dz04MDA-/http://www.backyardworkshop.com/images/stories/PlasticWobblerEngine/IMG_3812.JPG

brian Rupnow
05-19-2015, 01:21 PM
So now, after another four hours of modelling, it becomes clearer how this can be. The green support stanchions are fixed in position to a base. On the non carburetor side, there is a steel ball bearing setting in the recess at the end of the stub-shaft on the side of the cylinder. Then there is a 1/4" set screw resting against the outer side of the steel ball, locked in position with a 1/4" hex nut. On the carburetor side, there is a 1/16" cross section rubber o-ring (I will probably use Viton because of the heat.) setting between the end of the boss on the cylinder side stub-shaft which is hollow, and a flat bottomed counterbore in the green stanchion. This provides an air tight seal. The carburetor is bolted to the outside of the stanchion, and doesn't move. I will probably stick a paper gasket between the carburetor and the stanchion, but for now I haven't shown it. In one of the pictures, you can see the intake valve on the same end as the sparkplug--it is an atmospheric intake valve and requires no valve lifter. The exhaust valve is on the other side of the carburetor block, and will be operated by a lifter. There is a single hole in the side of the cylinder, and as in the Webster engine, it serves as both intake and exhaust port. You can see the (purple) head of the exhaust valve in the cross section.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/OVARALL%20ASSEMBLY--OSCILLATING-WITH%20CARB-1_zpsx1cef6hj.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/OVARALL%20ASSEMBLY--OSCILLATING-WITH%20CARB-1_zpsx1cef6hj.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/OVARALL%20ASSEMBLY--OSCILLATING-WITH%20CARB-2_zpswmuvtert.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/OVARALL%20ASSEMBLY--OSCILLATING-WITH%20CARB-2_zpswmuvtert.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/OVERALL%20ASSEMBLY--OSCILLATING-CROSS%20SECTION-2_zps0almtlzs.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/OVERALL%20ASSEMBLY--OSCILLATING-CROSS%20SECTION-2_zps0almtlzs.jpg.html)

brian Rupnow
05-20-2015, 04:59 PM
Hang on boys, I'm modelling as fast as I can!!! Wife and I had to drive to Hamilton this morning to welcome my newest grandchild, Benjamin--8 pounds 7 ounces born at 6:30 this morning.--Mom and baby are doing well---Ben looks just like me--No hair and no teeth!!! This engine is a four cycle. The carburetor is attached solidly to the dark green cylinder support stanchion, which does not move. Strange as it may seem, the valves are both mounted in the same block that holds the carburetor, so the valves don't move either. There is a cam lobe on the far side of the red gear, setting in a cut out area in the pale green crankshaft support and the "pinkish/purplish" rectangular part with the round dark blue pin in it is the exhaust valve pushrod. That round dark blue pin is the "exhaust valve lockout latch" that the "hit and miss lever" catches on to send the engine into "miss" mode.---More to come!!!---Brian
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/OVERALL%20ASSEMBLY--OSCILLATING_zpsr1jr8wdv.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/OVERALL%20ASSEMBLY--OSCILLATING_zpsr1jr8wdv.jpg.html)

aostling
05-20-2015, 11:43 PM
... the valves are both mounted in the same block that holds the carburetor, so the valves don't move either.

This necessitates an O-ring seal, which your drawing shows. The seal has to withstand the combustion pressure and temperature in the cylinder, with the inboard face undergoing oscillating rotary motion. Do you expect any problems with this?

brian Rupnow
05-21-2015, 07:38 AM
I'm not expecting a problem, and I will probably use a high temperature Viton o-ring. However, I am an optimist, and i never really expect insurmountable problems. if I thought it was going to be a really big problem, then I probably wouldn't attempt to build this engine.:D:D

brian Rupnow
05-21-2015, 09:42 AM
The modelling is completed for this engine, except for riser blocks under the baseplate so the flywheel doesn't hit the bench-top. NOW---This is the point at which I may do something really crazy!!! Remember how, in another thread I asked about an offset, gear driven flywheel. You will see that even if this flywheel did have "deflector blades" soldered into the lightening holes in the flywheel web, to create a fan effect, the air wouldn't blow on the cylinder where I want it to. Now--If I extended that crankshaft support block closest to the flywheel about 2 1/2" horizontally, moved the flywheel over the same amount and mounted it on a stub shaft attached to the crankshaft support block, and popped a couple of 2.5" o.d. spur gears in there, the flywheel would be right where I need it to be. One gear mounted on the end of the crankshaft and one mounted on the flywheel--the fan effect from the flywheel would blow directly over the cylinder fins. If it didn't work, I can replace the extended crankshaft support with one similar to what is shown in the model, move the flywheel back, and remove the gears. All I would be "out of pocket" for would be a couple of purchased hardened gears. (I could even make the gears myself for that matter.)---Whatcha think???
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/OVERALL%20ASSEMBLY--OSCILLATING_zpszawq7wu1.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/OVERALL%20ASSEMBLY--OSCILLATING_zpszawq7wu1.jpg.html)

Cuttings
05-21-2015, 11:13 AM
Good Morning Brian, at least it is morning out here.
Not trying to be picky but you would be blowing the air across the the cooling fins not along them like most air cooled engines do.
Don't know what the difference in cooling would be but I am sure it would make a difference.
Is there some way you could drive a fan to cool along the fins?

cameron
05-21-2015, 11:18 AM
I THINK those gears will have to be pretty good to stand the hammering they will get as the load reverses every revolution. Might be noisy as well.

brian Rupnow
05-21-2015, 11:37 AM
Cuttings--Since this will be a hit and miss engine, and will be drawing ambient room temperature air in and out of the cylinder during all of the "miss" cycles, it won't get very hot anyways. I just want the air around the fins to move a bit. It's a kind of "Any air movement is better than no air movement at all" kind of thing. Cameron--I hear you about the noise. I might dip into the Rupnow retirement fund and buy a set of gears with hardened teeth.---Haven't decided yet.---Brian

aostling
05-21-2015, 12:28 PM
... I just want the air around the fins to move a bit. It's a kind of "Any air movement is better than no air movement at all" kind of thing. ...

The fins are moving, so air movement is guaranteed without a fan. Are you thinking that will not be enough?

brian Rupnow
05-21-2015, 12:33 PM
Aostling--You are right of course. Since it is a hit and miss engine, it probably doesn't even need a fan.--I'm just playing and "imagineering".---Brian

Stepside
05-21-2015, 03:15 PM
Brian

Would a timing belt work better than gears? Just a thought as the flywheel is not timed. Or maybe a multi-V belt as it would be quieter than the gears and would let the flywheel slip a bit if needed.

Pete

brian Rupnow
05-21-2015, 04:11 PM
Stepside--If everything was bigger, then yes, a timing belt would probably work. However, on this small a scale, (The crankshaft is only 3/8" diameter) a belt small enough to match the scale of the engine wouldn't take the thrust pulses created by the engine when it fires, trying to move the 5 1/2" diameter flywheel.---That, plus the fact that on a hit and miss engine there are a lot of thrust reversals happening. When the engine fires, it drives the flywheel. As soon as the engine stops firing, then the flywheel drives the engine. Belts (and gears) like a steady thrust in one direction only.---Brian

hitnmiss
05-22-2015, 11:25 AM
I think it begs for some sort of bellows to utilize the oscillating motion to move air...

Cool engine. Pun not intended.

brian Rupnow
05-22-2015, 08:10 PM
Something unusual here---In his book 'The Shop wisdom of Philip Duclos' where these plans originated, Philip specifies the use of "Hot rolled or cold rolled steel" for the cylinder. He specifies cast iron for the rings. Okay--I can see the need for the strength of steel as opposed to cast iron because of the two pivot bosses on the outer walls of the cylinder, but I have never seen steel specified for a cylinder before. I don't think that it is a mistake. I'm just very curious as to whether steel will work satisfactorily for the application.--Any opinions??----Brian

aostling
05-22-2015, 08:23 PM
I was assuming the cylinder would be aluminum, chosen for its high thermal conductivity. That would minimize thermal gradients and warpage, and increase heat transfer to the fins.

brian Rupnow
05-22-2015, 08:52 PM
Allan--I really wish I could make it of aluminum, it would be so much easier to machine. Almost every plan I have ever seen calls for the cylinder to be cast iron, and any that have an aluminum cylinder always call for a cast iron liner. I know, my weedeater, chainsaw and lawn mower all have gas engines with aluminum cylinders, and they seem to get away with it just fine. The aluminum I use is just common bar stock purchased from my local metal supplier, and I have never asked what grade it is. Probably 6061, but I'm not sure. I don't know if all the other hundred million small engines with aluminum cylinders are running some special aluminum material that I don't have access to. I hope I get some more insight into this before I actually begin the build process.---Brian

OKChipmaker
05-22-2015, 08:52 PM
If I remember right Ford used steel in the early flat head V8s,sleeves in a cast iron block.The 60s series made in the 1930s

brian Rupnow
05-23-2015, 01:14 PM
If I make the cylinder from cast iron, it will be fairly easy stuff to work with. The only issue I see with cast iron is that the bosses on the sides will be fairly delicate---will need to use a very sharp tool when machining them or they will pop right off of the main cylinder block.--(Don't ask me how I know this!!) However, the bore and fins are pretty easy to machine in cast iron. If I make the cylinder from aluminum it will be super easy to machine, and will be very "flashy", but I don't think the pivot bosses would last very long, and I don't know how the bore would stand up to interaction with a sharp edged cast iron ring on the piston.--Would probably be okay with a Viton ring and a bit of oil mixed with the fuel for lubrication. --Could possibly press fit a thin bronze bushing over the cylinder bosses to take the "wear factor" from oscillating. Steel would definitely be the material of choice in regards to strength and wear factor of the pivot bosses, and it wouldn't be too bad to machine the bore and the outer shape and the bosses.--Could however, be a real "bear" to machine the fins into. I plan on using an HSS slitting saw to cut the fins.--Decisions, decisions--

brian Rupnow
05-23-2015, 03:24 PM
The cylinder is pretty simple. The slots which create the fins are the scary part. I know my small mill does a great job cutting .094" wide x 3/8" deep in aluminum. Probably it wouldn't grunt at cast iron. Steel though---Ah, Jeez, I'm not sure about that.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYLINDER-OSCILLATING_zps2knwt2ec.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYLINDER-OSCILLATING_zps2knwt2ec.jpg.html)

aostling
05-23-2015, 07:40 PM
...I don't know how the bore would stand up to interaction with a sharp edged cast iron ring on the piston.--Would probably be okay with a Viton ring and a bit of oil mixed with the fuel for lubrication.

I like that idea. If you are going to use a Viton O-ring at the trunnion ends you might as well use them on the piston too.

brian Rupnow
05-23-2015, 08:36 PM
Aostling--I have tried numerous times with very little success to make my own cast iron rings. Viton works extremely well, but I always wonder with hit and miss engines if I would get longer "miss" cycles if I used cast iron rings, which have considerably less "drag coefficient" inside the cylinder.

Duffy
05-23-2015, 11:02 PM
Brian, just a thought. A buddy of mine bought some CI bar in the states, (it does not EXIST in Ottawa!) I THINK the supplier was Speedy Metals but I can check. The most important point was shipping. He bought a foot, but it would not fit in an international flat rate box. I suggested that he order it cut in half-no problem. Shipping to his door was about $19.00. The point here is that you could order square or rectangular bar in short lengths without being beggared by FEDEX/UPS shipping/brokerage charges.

brian Rupnow
05-24-2015, 07:05 AM
Thanks Duffy----Brian

boslab
05-24-2015, 07:36 AM
I suppose it would be possible to remelt weed eaters or whatever and cast a block then machine out of that?, I'm guessing barstock iron has not been homogenised to allow the thin section required of a piston ring to be made without crumbling, centrifugal cast might be better perhaps, never made one so guessing but you never know, is there a heat treat that could help the iron out a little?
Mark

brian Rupnow
05-24-2015, 08:58 AM
Or---How about an alternate design--aluminum cylinder with radial grooves (easier to make on a lathe), thicker cylinder wall, and hard press fitted steel pivots?
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/SUB%20ASSY-ALTERNATE%20CYLINDER_zps47bg1aw0.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/SUB%20ASSY-ALTERNATE%20CYLINDER_zps47bg1aw0.jpg.html)

aostling
05-24-2015, 09:08 AM
That looks like a great improvement.

What is the displacement of this engine? With no connecting rod it can have a long stroke with no side-loading on the piston. If it is about 10cc it could do some useful work.

brian Rupnow
05-24-2015, 09:32 AM
Without getting too far into fixing up the other bits--it would look like this.--Kinda cool, I think!!--it has, in this guise, a 7/8" bore and a 1 3/8" stroke.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/OVERALL%20ASSEMBLY--OSCILLATING_zpscmxddw1g.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/OVERALL%20ASSEMBLY--OSCILLATING_zpscmxddw1g.jpg.html)

Lew Hartswick
05-24-2015, 09:33 AM
I'm not a "modeler" but this looks like a proj I could enjoy. it's unusual enough to be interesting. :-)
...lew...

EddyCurr
05-24-2015, 11:28 AM
Engines with linerless aluminum cylinders may be
cast from Reynolds A390, or something similar.
A390 is "a hypereutectic alloy saturated with silicon,
such that silicon particles are dispersed throughout
the alloy similar to chocolate chips in cookies."


Honing Options for Hypereutectic Aluminum Cylinder Bores (http://www.sunnen.com/NewsDetails.aspx?NewsID=11)
Courtesy: Sunnen

It may be possible to melt and recast A390. However,
as noted in the article above, there are some challenges
to the HSM when it comes to final cylinder finish preparation.

.

brian Rupnow
05-24-2015, 11:42 AM
Eddy--The only thing I have ever cast is stones at the neighbors dog. That cylinder reminds me of the bee-hive that used to be on the old Bee-Hive Cornsyrup cans. Of course, you have to be a long ways on the wrong side of 50 to remember them cans.

brian Rupnow
05-25-2015, 09:02 AM
Okay---the jury has decided. It is going to be an aluminum cylinder with pressed in steel pivots. I have had to do a few strange and wonderful things to accomplish this. The engine as originally designed had a 4.5:1 compression ratio, and a 1" bore. I determined that when the piston is at top dead center, it stops .050" before the side of the pivot hole in the side of the cylinder. So--I reduced the diameter of the bore to 7/8" from the outboard end of the cylinder to .025" past the hole for the pivot. That gives me an extra .062" of wall thickness to hold the pressed in pivot pins in place, and still leaves .025" clearance between the top of the point where the 1" diameter piston stops it's upward travel and the beginning of the reduced bore diameter. This of course increased the compresion ratio to a higher number. Fortunately, the original design had the inside of the cylinder head extending down into the cylinder itself by a considerable amount. I was able to shorten this intrusion into the cylinder by a sufficient amount to restore the compression ratio to what it should be.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYLINDER%20ASSEMBLY-OSCILLATING-2%20BORES_zpsbyv9mm62.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYLINDER%20ASSEMBLY-OSCILLATING-2%20BORES_zpsbyv9mm62.jpg.html)

brian Rupnow
05-25-2015, 09:47 AM
Like this---
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/ALTERNATE%20CYLINDER_zps3aqspegr.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/ALTERNATE%20CYLINDER_zps3aqspegr.jpg.html)

brian Rupnow
05-25-2015, 09:56 AM
I just had an amazing idea. In the cross section of the cylinder, you can see the extra "breather holes" cut in the cylinder con-rod guide to prevent pulling a vacuum when the piston is on it's way up from dead center.-This means that every time the piston travels down, a puff of air comes out of those holes. if I went absolutely steam punk crazy, and made up a couple of 180 degree u-bends in brass hollow tubing and fitted them into two of the top holes, they would blow a blast of air over the cooling fins with every revolution of the crankshaft, as the piston travelled down in the bore!!

brian Rupnow
05-25-2015, 12:13 PM
Check this out!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/th_OVERALL%20ASSEMBLY--OSCILLATING_zpsydvnel59.mp4 (http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/OVERALL%20ASSEMBLY--OSCILLATING_zpsydvnel59.mp4)

aostling
05-25-2015, 03:12 PM
... if I went absolutely steam punk crazy, and made up a couple of 180 degree u-bends in brass hollow tubing and fitted them into two of the top holes, they would blow a blast of air over the cooling fins with every revolution of the crankshaft, as the piston travelled down in the bore!!

This idea should be shelved, unless you find overheating to be a real problem. All this air-pumping work comes at the expense of shaft work (which you will be able to apply to a useful task).

brian Rupnow
05-25-2015, 03:39 PM
That's it!! All of the modelling is finished. I know the design has evolved since I started, but that is the nature of design. Sometimes I have to design a thing and look at it for a while before I decide whether or not it is practical or pleasing to my eye.---or "do-able" on conventional machine shop tooling. I don't know when I will actually start building this engine, but it probably won't be too far off. I will build the cylinder first, because that will be the trickiest bit of machining.---And Oh yeah--The jury is still out on those inserts in the flywheel, but they would create air flow!!!---Brian
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/OVERALL%20ASSEMBLY--OSCILLATING_zpsvwqnrlcq.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/OVERALL%20ASSEMBLY--OSCILLATING_zpsvwqnrlcq.jpg.html)

brian Rupnow
05-25-2015, 09:01 PM
Gotta have a plan of attack---
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYLINDER%20TURNING%20PLAN%20002_zpsbbn4naff.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYLINDER%20TURNING%20PLAN%20002_zpsbbn4naff.jpg.ht ml)

Cuttings
05-26-2015, 11:01 AM
Brian - I think that is a smart idea to think through your procedure and make some notes before you start.
I usually keep the procedure in my head( which sometimes doesn't work as well as it used to) and have more than once got myself in a bind
because I missed a step that is difficult to go back to.

brian Rupnow
05-27-2015, 11:44 AM
That went amazingly well!! I have to stop now and do some real work, but you have to admit--that IS a graceful shape.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/cylinder-first%20stage%20turning%20001_zpswsyavjzs.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/cylinder-first%20stage%20turning%20001_zpswsyavjzs.jpg.html )
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/cylinder-first%20stage%20turning%20004_zpsvhr70bzz.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/cylinder-first%20stage%20turning%20004_zpsvhr70bzz.jpg.html )

RichR
05-27-2015, 12:28 PM
I was wondering when the chips would start flying. Beautiful work as always Brian.

brian Rupnow
05-27-2015, 05:41 PM
Well, THAT was a very interesting hour!!! My goodness, I love that mounted digital caliper.-I have never cut such accurate, consistently spaced fin grooves before. Nothing jammed, nothing broke, and I cut them at 215 RPM which is faster than I have ever used before, using my HSS parting tool and lots of dripped on cutting oil.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/FINS%20ON%20CYLINDER%20003_zpsfojezc5m.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/FINS%20ON%20CYLINDER%20003_zpsfojezc5m.jpg.html)

wendtmk
05-28-2015, 09:13 AM
Makes ya almost feel like you're cheatin', don't it? ;-)

Mark

brian Rupnow
05-28-2015, 09:40 AM
Cylinder has had one end cut off and is bored to 1" diameter. Actually, it has two sizes of bores, 1" where the piston travels, and 7/8" in the actual combustion chamber. The holes have been drilled and tapped in the visible end. I always have to be very careful on a part like this that I don't "paint myself into a corner" and find that there is nothing to hold onto to do farther stages of machining.--I can now make a 1" diameter arbor that has a flange in the middle for bolting to the end of the cylinder which is drilled and tapped. On one side of the flange, the arbor extends into the bore of the cylinder, right up to the step in the bore. On the other side of the flange, it sticks out a couple of inches so I can hold it in the chuck on my lathe to part of the other end and into the chuck on my rotary table to machine the flats on each side and the through holes.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYL.%20BORED%20ONE%20END%20TAPPED%20002_zpshaws4lx y.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYL.%20BORED%20ONE%20END%20TAPPED%20002_zpshaws4lx y.jpg.html)

Black Forest
05-28-2015, 11:50 AM
Brian your first picture of your cylinder looked like you were turning your own urn for your own ashes! I thought wow, Brian is really into this machining thing!

brian Rupnow
05-28-2015, 04:34 PM
My ashes would be too big to fit in an urn that size-----

brian Rupnow
05-28-2015, 06:18 PM
So far, we're right on track. I know this cylinder is making things picture heavy, but it is a multi-step operation, and the new-bees appreciate the step by step pictures. The next thing will be a trip over to the mill to tap the bolts in the cap end, and then into the rotary table to mill the flats and the drill/ream the pivot holes. I have a bit of a sneaky feeling that this aluminum may be too soft to run without a liner, but Hey--Nothing ventured -Nothing gained!! I've checked it out already, and if it is too soft, I can but in a cast iron liner and run a 7/8" piston.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/ALMOST%20FINISHED%20CTLINDER%20014_zpsgp8nopzx.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/ALMOST%20FINISHED%20CTLINDER%20014_zpsgp8nopzx.jpg .html)

brian Rupnow
05-30-2015, 09:17 AM
The cylinder is finished. all went very well, with no mishaps, until when I was taking it out of the mill I realized that the flats were cut 45 degrees out of phase. I thought briefly of committing Hari-Kari, but then realized that this was a good thing. The pressed in steel pivot pins will now be directly under two of the head bolts, so I can extend the thread right into the steel pivots and that will act as some additional "security" to keep the pivot pins from trying to escape, and will give more thread for the two head bolts directly over the pivots. Setting on one side of the cylinder is a cut off section from the piece of aluminum I started with ---it will become the cylinder head. On the other side is a chunk of 660 bronze, which will be the con rod guide on the other end of the cylinder.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYLINDER%20FINISHED%20002_zpsm4vb0l2n.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYLINDER%20FINISHED%20002_zpsm4vb0l2n.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYLINDER%20FINISHED%20003_zpstafw4ydl.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYLINDER%20FINISHED%20003_zpstafw4ydl.jpg.html)

Lew Hartswick
05-30-2015, 09:34 AM
re the "miss-located" holes: I believe that is a good example of rationalization. :-)
...lew...

Black Forest
05-30-2015, 10:55 AM
Brian, your sub-conscious engineer saved your bacon on the flats.

brian Rupnow
05-30-2015, 11:39 AM
I'm really good at finding some way to rationalize my own screw-ups.:p:p

brian Rupnow
05-30-2015, 03:20 PM
No matter how I rationalized it, it just wasn't going to look good. So--I put in a second set of tapped holes in each end, and offset the hole pattern 45 degrees from the flat areas. The set of holes I don't use will be covered up by the caps bolted to both ends of the cylinder. I have an "undersize" 3/8" reamer (0.3735")which I used to ream the cross hole of the cylinder. All of my cold rolled round stock is .001" undersize, so I turned the pivots from 01 drill rod to an exact .375", coated them with "press fit" #648 Loctite and after putting a 7/8" diameter slug in the top of the cylinder to guard against flattening it, I pressed the pivots in with my 1 ton arbor press. They went in HARD!!! I now see that I have milled away more fins on the sides than I intended to, but I'm going to have to live with that. That is one of the dangers of designing your own stuff and having two or three "iterations" of the same part.--You lose track of what you are doing when you actually make the part. Overall, though, I' liking this!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/pivots%20in%20cylinder%20001_zpsvk5h4v0e.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/pivots%20in%20cylinder%20001_zpsvk5h4v0e.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/pivots%20in%20cylinder%20002_zps50fpac7x.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/pivots%20in%20cylinder%20002_zps50fpac7x.jpg.html)

brian Rupnow
05-30-2015, 06:52 PM
And so, the end of a good day. Making parts, fixing mistakes, and taking time out in the middle of the day to put up a clothes line for my oldest son's mother in law. (And yes, there is a story to that, but I won't tell it here!!) That's just a dummy con-rod sticking in the brass con rod guide. If a person had a yard of that 660 bronze, you could trade even for a small island in the Caribbean. If I sleep tonight and goodwife doesn't have any plans for me tomorrow, I'd like to make the cylinder head.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CON%20ROD%20GUIDE%20FINISHED%20003_zpswuuoklfl.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CON%20ROD%20GUIDE%20FINISHED%20003_zpswuuoklfl.jpg .html)

brian Rupnow
05-31-2015, 02:14 PM
And now you know how I spent my Sunday, or at least a good portion of it. Lets see--I started at 6:00 this morning and it's 2:00 PM now. That's 8 hours, but I took half an hour to eat and 21/2 hours to model a conveyor for a customer. so---That cylinder head is a five hour part. It isn't perfect, but it's good!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYLINDER%20HEAD%20FINISHED%20001_zpstm4xnuou.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYLINDER%20HEAD%20FINISHED%20001_zpstm4xnuou.jpg.h tml)

brian Rupnow
06-03-2015, 12:42 PM
This morning I built the two stands that the cylinder sets in to "oscillate". What you don't see in the pictures are the bronze bushings I pressed/loctited into the aluminum stands. On the thick stand, there is a steel ball that fits into a coned recess in the pivot shaft, and a threaded set-screw in the stand that puts some pre-load on the cylinder so it sets up tight against an o-ring seal which is buried inside the other pivot stand. In he other angular support stand you can see the two #4-40 threaded holes that the carburetor and valve body attaches to.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYLINDER%20STANDS%20001_zpsolxfbsxv.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYLINDER%20STANDS%20001_zpsolxfbsxv.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CYLINDER%20STANDS%20002_zps1mz8acpc.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CYLINDER%20STANDS%20002_zps1mz8acpc.jpg.html)

brian Rupnow
06-03-2015, 09:06 PM
By the way---Did I ever mention how much I dislike machining steel?? I am badly spoiled by using mostly aluminum and brass for the things I build. My relatively small mill likes it that way too. However---There are times when nothing will do but steel. Such is the case with the piece in the foreground of the picture. The 1/2" hole gets an oilite bushing to support the crankshaft, the 1/4" hole in the bottom of the counterbore gets a stationary camshaft, the counterbore is where the cam attached to the large timing gear lives, and the horizontal slot is where a bronze pushrod goes. The pushrod is rectangular, and has a slot in two opposing sides which fits over the steel slot to guide and support it, and one end rests against the cam. I didn't have any cold rolled steel to make this part, but I remembered seeing a rusty, crusty piece of 1" thick hot rolled in my "metal storage bin". I did a bit of searching and found it, and was able to carve this fairly reasonable piece out of it. I still have a lot of work to do to finish it, but it is an interesting part of the engine.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/PUSH-ROD%20GUIDE%20IN%20PROGRESS%20001_zpsvcvbjdra.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/PUSH-ROD%20GUIDE%20IN%20PROGRESS%20001_zpsvcvbjdra.jpg. html)

aostling
06-04-2015, 12:19 AM
It is unusual to have both intake and exhaust controlled by a single cam. I suppose the cam has a dwell, otherwise you might get by with a sinusoidal drive off an eccentric.

What is the shape of the cam profile?

brian Rupnow
06-04-2015, 07:38 AM
The intake valve is an atmospheric valve, and is not operated by a cam.

MrSleepy
06-04-2015, 08:32 AM
Won't you get horrendous pumping losses from the underside of the piston trying to pump the air out through those 4 tiny holes ?.

Rob

Lew Hartswick
06-04-2015, 09:25 AM
Won't you get horrendous pumping losses from the underside of the piston trying to pump the air out through those 4 tiny holes ?.

Rob
I Wonder about that the first picture I saw of it.
Brian ?? Bigger holes??
...lew...

hitnmiss
06-04-2015, 10:01 AM
All my old rc 4-stroke motors had a small hole to vent the crankcase (mainly to let oil out) and they seemed to run fine. I imagine every rev creates a small vacuum / pressure in the crankcase that is returned to the piston by sucking and blowing on the bottom of the piston. If that's the case, a bigger hole could actually increase the pumping losses.

aostling
06-04-2015, 03:35 PM
... If that's the case, a bigger hole could actually increase the pumping losses.

Yes, up to a point. The four holes in the end plate act like a Jake Brake. Somewhere between a small hole and a large hole the braking effect will be maximized.

aostling
06-04-2015, 03:44 PM
The intake valve is an atmospheric valve, and is not operated by a cam.

Now I remember you mentioning this. A reed valve would be a simple solution for the intake port.

brian Rupnow
06-04-2015, 08:29 PM
I did a quick math check, and you are right. There is a big difference in the area occupied by the piston minus the con-rod, compared to the cross sectional area of those four holes. It will be interesting!! If there is a problem, I will drill 4 more holes. It may not be an issue though. I will take a "wait and see" approach.

aostling
06-04-2015, 10:23 PM
... If there is a problem, I will drill 4 more holes.

Try plugging three of them first.

Lew Hartswick
06-05-2015, 09:38 AM
Try plugging three of them first.

Sure and while youre at it might as well put a spark plug in that end and make it double acting. :-(
...lew...

brian Rupnow
06-05-2015, 08:06 PM
I've had so much unexpected "drop in" engineering design work, that I am considering buying a new milling machine. (To get rid of some of the money!!) My BusyBee Craftex CT129 is still going strong, but I would like something a bit bigger, stronger, newer. I don't want a knee mill, I am quite satisfied with the square column mill-drills that are available. Busy bee has a new 1 HP mill, with a larger x and y movement and an R8 spindle taper. It is 110 volt, which is a good thing because I don't have 220 volt available in my small machine shop. Of course, this means that along with the mill, I will have to buy a new boring head, because mine has an MT2 taper and it is not the removable shank type. The mill comes with a chuck, but I would have to buy a 1/2"-R8 collet and a 3/8" R8 collet to hold my milling cutters, and I think it's about time I had a new electric center finder. The price for everything including the sales tax is just under $3000, and my wife says "Go ahead!" Damn, I love that woman!!! I just came home and measured the space available in my machine shop, and the new mill is so much bigger than what I have that either the bandsaw or the 1" belt sander or maybe both will have to move out to the main garage. My "machine shop" is a seven foot square annex of one corner of my design office that never got used---it had an enormous old drafting table in it that never got used, so when I began this machining hobby 5 years ago the drafting table went and a wall was built to separate the machining area from the office area. I may be about to outgrow things---
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/out%20of%20space%20003_zpsmkdmvwl5.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/out%20of%20space%20003_zpsmkdmvwl5.jpg.html)

brian Rupnow
06-07-2015, 05:22 PM
I couldn't let the whole weekend get away without building at least one part for the engine. We now have an outboard crankshaft support complete with bronze bushing (and no, I didn't use Loctite on it.) I have had a crazy/busy weekend working for a customer, doing 8 hours work which I had estimated and quoted at 4 hours work--(Hate it when that happens), painting headboards for grandkids new beds, and cutting dangerous trees out of the fenceline between me and the neighbour. There are two holes yet to be tapped in that aluminum part I just made for ignition points, but I will wait till I have the ignition points in my hand to check the hole position first.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/OUTBOARD%20CRANKSHAFT%20SUPPORT%20002_zpsr5iqvjbt. jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/OUTBOARD%20CRANKSHAFT%20SUPPORT%20002_zpsr5iqvjbt. jpg.html)

brian Rupnow
06-10-2015, 07:41 AM
A crankshaft web in the process of being born. I have decided to make this a 3 piece crankshaft, pressed together. The web is 5/16 crs flatbar. A couple of tricks are involved here. #1--when drilling/reaming the holes for the crankshaft and the rod journal, don't use the mill vice. Put a flat piece of sacrificial plate on top of the mill table and clamp the bar which will become the web to the flat plate. Vices (at least the vices I can afford) always tip the piece being milled a small bit when closed on the part, and if you drill/ream these holes while the piece is held in the vice, the rod journal will orbit as it rotates, and you definitely don't want that. I use an undersize reamer for the two critical holes, at 0.3735" diameter. I use drill rod for the crankshaft, because it comes in at .00025 to .0005" oversize A total of .0002" interference seems about right for this size of stock when press fitted together. If, in my judgement the pieces don't press hard enough, I will cross drill and dowel with a .093" hardened pin.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CRANKSHAFT%20WEB%20001_zpsqs6sulj9.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CRANKSHAFT%20WEB%20001_zpsqs6sulj9.jpg.html)

aostling
06-10-2015, 06:13 PM
I see the two curves of R1.000 and the central hole all have a common center. Would it be easiest to turn those curves out in the lathe (after rough sawing)?

brian Rupnow
06-10-2015, 07:08 PM
Allan---I have a gigantic vertical belt sander that I built years ago for smoothing flame cut brackets for hot-rod building. It smooths that curved line out after rough cutting with the bandsaw in seconds.---Brian

brian Rupnow
06-10-2015, 08:27 PM
Tonight I finished the crankshaft web. The holes are reamed with a 0.3735" reamer. The crankshaft itself is made from 01 drillrod, which is about .0005" oversize, or 0.3755" diameter. The part with blue dye on it is a full 0.3755" diameter, and it will be the "pressed" area. The short polished area at one end has been polished down to 0.3735" for a "lead" into the hole in the web. The long polished area has been taken down to 0.375" to fit through all the bores and bushings it has to go in. I used #220 grit emery cloth strips 1" wide to do the polishing with. When I press it into the web, it will stick out about 1/2" on the "off" side. I do this to ensure that it doesn't go in crooked, which can happen when you are pushing through a relatively thin web---5/16" in this case. I will trim that end off flush with the web after the pressing is done. All pressing will be done with both pieces at room temperature. My 1 ton arbor press is not powerful enough to do this pressing, and my mechanics bench vice won't open far enough to do the job. I will take it to the factory where I am currently doing a bit of design consulting and use their 12 ton press for this operation. When I press in the short piece of crankshaft that the con rod fits onto, I will use my bench vice.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CRANKSHAFT-1%20001_zpscmxprhj4.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CRANKSHAFT-1%20001_zpscmxprhj4.jpg.html)

brian Rupnow
06-10-2015, 08:53 PM
And check out that crazy bronze exhaust valve push-rod!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/EXHAUST%20VALVE%20PUSHROD%20001_zpslawrgz2u.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/EXHAUST%20VALVE%20PUSHROD%20001_zpslawrgz2u.jpg.ht ml)

brian Rupnow
06-11-2015, 03:46 PM
The Rupnow Retirement Fund took a big hit today!!! A brand new milling machine from BusyBee. This thing is a monster compared to my old Craftex CT129 that I bought 6 years ago. This one is 110 volt, with a 1 1/2 HP motor. The travel in X axis is 16" and in Y axis is something like 8 1/2". It has an R8 spindle taper. I decided to buy a base for this one instead of making my own from angle iron like I did with my first mill. This thing is majorly heavy compared to my old mill. I know because I just unloaded it out of my pickup by myself with my old faithful cherry-picker engine hoist. It seems to be quite unstable, with high center of gravity. I will arrange some temporary bracing from 2 x 4`s to keep it from accidentally tipping over until I get it to it`s final resting place and can tie the top of the stand into the studding in a wall.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/NEW%20MILLING%20MACHINE%20001_zps1jxo0ix1.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/NEW%20MILLING%20MACHINE%20001_zps1jxo0ix1.jpg.html )

Toolguy
06-11-2015, 05:04 PM
Good for you Brian!!! I think you will find that the larger real estate makes life easier.

brian Rupnow
06-11-2015, 05:57 PM
I can see a problem already. My old mill moved .002" for every graduation on the X and Y dials, and the table moved exactly 0.100" for each full turn of the dial.---On the new mill, each graduation represents .0025", and one full turn of the dial makes the table travel 0.125".:eek::eek: It's not a question of which one is right and which one is wrong---It's a matter of me unlearning almost 6 years of moving .002" per graduation.--Wonder what I will screw up first???

ammcoman2
06-11-2015, 06:18 PM
DRO, DRO. Spend the rest of your booty on one.

I have a Shooting Star unit on my 8x30 mill and, in over 10 years, has never given any problems. The new ones can do bolt circles, which mine can't (have a calculator for that now).

You will never pine for the old dials once installed. My mill has .125" per rev and it would drive me crazy.

Geoff

Cuttings
06-11-2015, 07:09 PM
Looks good Brian. I have a mill lathe combination I bought from Busy Bee and I also bought the cabinet to sit it on.
I found the cabinet to be on the flimsy side so made up some bars to put inside which I bolted through when mounting the lathe.
It still moves a little but has not caused me any problems yet.

brian Rupnow
06-11-2015, 08:11 PM
I have an idea percolating--I can probably sell my old mill with all the tooling for enough money to buy a set of decent DRO's for my new mill.

Toolguy
06-11-2015, 09:20 PM
Sounds like a great plan. Get a DRO. You will wonder how you ever did without it.

brian Rupnow
06-12-2015, 07:27 PM
And behold!!! Tonight we have a finished crankshaft. We almost had a finished con rod, but I got fooled----badly. I hunted around in my "bits and pieces" drawer and found what appeared to be a nice piece of 3/8" brass or bronze. I did my laying out, milled the profile, drilled and reamed the hole for the crankpin, put in the counterbore that the end of the con rod fits into, and was very pleased with myself. It was only on the final cut to part it off from the parent stock that it split cleanly in two!! What the Heck!!! It was only on close examination that I discovered that at some time in the past I had epoxied two pieces of 3/16" brass or bronze together for some reason.---RATS!!! Tomorrow I will make the same piece over again from real 3/8" material.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CRANKSHAFT%20FINISHED%20002_zpswdmfupx7.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CRANKSHAFT%20FINISHED%20002_zpswdmfupx7.jpg.html)

RichR
06-12-2015, 09:48 PM
It was only on close examination that I discovered that at some time in the past I had epoxied two pieces of 3/16" brass or bronze together for some reason.
No doubt you did it to pull a prank on yourself in the future, and you executed it to perfection.

brian Rupnow
06-13-2015, 12:41 PM
The big move is about to commence. the bandsaw moves out to the main garage. The old mill moves out to the main garage until I can sell it, and the new mill moves into my machine shop. I went up to BusyBee this morning and bought a machinery moving dolly, and I must say I am rather impressed. I don't think I would recommend it for moving a Bridgeport around on, but for machinery in the "under 700 pound" category, I think it's just the "cats meow!!!" All the other men I know are old farts like me, and I have two big strong sons, but one lives in a far off city and the other one is sick.-----So---This move will be a "Brian by himself move" as is generally the case. i think this little "cart" is going to be a real asset.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/MACHINE%20MOVER%20001_zpshmcsmujt.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/MACHINE%20MOVER%20001_zpshmcsmujt.jpg.html)

brian Rupnow
06-13-2015, 03:44 PM
And so, my lads, we have the "Naked Machine Shop". The machinery moving cart worked marvelously, as advertised. The bandsaw and old mill are both out in the main garage. No tipped machinery, no mashed fingers, not even a tense moment really. Just very, very slowly and carefully, like porcupines making love!! I even washed 5 or 6 years of accumulated crud off the wall behind the mill!! Tomorrow I will do a big clean-up on the old mill and get it ready to advertise for sale. I don't want to move the new mill into place until I get this DRO business resolved, because the mill sets up against a wall in it's final position and I think I may have to drill and tap something on the back side of the carriage to hold a scale.---Much easier to do before I move it from the garage, where it has access all around it.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/NAKED%20MACHINE%20SHOP%20001_zps5uozarwn.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/NAKED%20MACHINE%20SHOP%20001_zps5uozarwn.jpg.html)

brian Rupnow
06-16-2015, 01:16 PM
I actually managed to have a free morning at home today, so I thought I had better do something to keep this engine thread alive. I won't have access to a mill until my DRO's arrive and are installed, so I decided I would make as many round parts as I could on the lathe. I have turned and bored the blanks which will become my timing gears, plus enough extra gears to help out some poor fellow in USA who got my Rupnow Engine-2 three quarters built and then found out you can not purchase these particular gears---you have to make them!!! I also made the cam shaft, the bushing which presses into the cam gear, the ignition cam and the governor spool.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/OSCILLATING%20ROUND%20PARTS%20003_zpsbwcxhbmo.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/OSCILLATING%20ROUND%20PARTS%20003_zpsbwcxhbmo.jpg. html)

brian Rupnow
06-17-2015, 05:43 PM
I am now a card carrying member of the infamous "Hole in the Wall Gang"!!! The new mill was about 4" thicker through than the old CT129 mill, and I couldn't afford the amount it would have protruded into my work space between the lathe and the mill. I will gain my 4" back by cutting a hole as shown The hole doesn't protrude into the adjoining room (which is just storage space anyways.) I gained back my 4" of space because the drywall was 1/2" thick and the "2 x 4" is actually 3 1/2" thick. I didn't cut through the bottom "footer" of the wall, because I didn't want to mess with the structural integrity of the wall itself. I will build a 1 1/2" thick x 3" wide rectangular steel tubing spacer to go under the front and two sides of the mill stand, and the back side of the stand will rest on top of that "footer". I still have to frame in the top and one side of the opening with 2 x 4's, and do a bit of trimming and plastering. I will have that finished by the time my DRO kit gets here.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/HOLE%20IN%20THE%20WALL%20001_zpsfubxsomf.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/HOLE%20IN%20THE%20WALL%20001_zpsfubxsomf.jpg.html)

bob_s
06-17-2015, 06:12 PM
Creative outside the box engineering at it's best!

brian Rupnow
06-18-2015, 06:24 PM
For all you Canadians out there, who might consider buying this CX601 mill from BusyBee tools--A word of caution!! My old CT129 mill was set up so that each increment on the X and Y dials was .002" of table travel, and one full turn of a dial moved the table an exact 0.100". This made for a very easy mental calculation to determine how far you moved the table in either the X or Y axis. For some unknown reason, this new mill is .0025" movement for each graduation, and the table moves an exact 0.125" for one full turn. I checked this with a dial indicator, and it is correct.----This moves things into the realm of impossibility to do any kind of mental calculation of how many full turns and graduated marks you must turn the dials to move a given distance.----So---If you buy this mill, be prepared to use a calculator to figure out every move of the mill table, or shell out close to $1000 for a two axis DRO set-up. In my opinion, this is just about the stupidest thing I have ever seen. Caveat Emptor!!! (Buyer Beware.) If I had known about this before I bought the mill and got it home, I wouldn't have bought this particular mill.

TGTool
06-18-2015, 08:25 PM
Reminds me of a situation a year or so ago. I make machine dials and got a request for a dial that was graduated in metrics but without changing the leadscrew. Yes, it could theoretically be done but I told them they wouldn't like it. I could have produced a dial that would give a metric increment but there would have been a tiny fraction at the end. In other words, the very last space on the dial would have been slightly smaller. Try to keep THAT in your head through multiple turns of the crank.

aostling
06-18-2015, 11:46 PM
... If I had known about this before I bought the mill and got it home, I wouldn't have bought this particular mill.

This is really an injustice. Is there no possibility of returning the mill?

chipmaker4130
06-19-2015, 02:04 AM
Brian, you have the skill to make larger dials and graduate them the way you want!

Toolguy
06-19-2015, 09:30 AM
He is already doing the easiest and best fix...DRO. A DRO is a major improvement even on a Bridgy or other machine that doesn't have any leadscrew problems. The 3 major machinery improvements of the 1900's were the Aloris quick change toolpost for the lathe, Digital Readouts and CNC.

chipmaker4130
06-19-2015, 10:20 AM
Sure, its the best. It's also the most expensive. I'd love to have a DRO but its totally out of my range.

brian Rupnow
06-19-2015, 12:07 PM
I'm really not looking for the sympathy vote here. After six years of milling only using the dials, I was beginning to wonder just how nice it would be to have a DRO set-up, but simply don't do enough "for pay" milling to justify the expense. Fortunately, I have had two steady months of engineering design work, which pays for the mill and accessories. I have sold the old mill and a bunch of other tools which I no longer use, and that has pretty well covered the cost of the DRO set I have on order. I do use my lathe and mill for quite a bit of prototype work for some of my customers, but it is all very "hush-hush" stuff. I think it is a good milling machine. It is very robustly built, and has a whopping great 8 1/2" travel in Y axis and 23 1/2" in the X axis travel. It's just that I really resent being forced into buying a DRO kit because of the way the dials are set up.---Brian

TGTool
06-19-2015, 03:58 PM
For all you Canadians out there, who might consider buying this CX601 mill from BusyBee tools--A word of caution!! My old CT129 mill was set up so that each increment on the X and Y dials was .002" of table travel, and one full turn of a dial moved the table an exact 0.100". This made for a very easy mental calculation to determine how far you moved the table in either the X or Y axis. For some unknown reason, this new mill is .0025" movement for each graduation, and the table moves an exact 0.150" for one full turn. I checked this with a dial indicator, and it is correct.----This moves things into the realm of impossibility to do any kind of mental calculation of how many full turns and graduated marks you must turn the dials to move a given distance.----So---If you buy this mill, be prepared to use a calculator to figure out every move of the mill table, or shell out close to $1000 for a two axis DRO set-up. In my opinion, this is just about the stupidest thing I have ever seen. Caveat Emptor!!! (Buyer Beware.) If I had known about this before I bought the mill and got it home, I wouldn't have bought this particular mill.

The leadscrew setup for that is a puzzle to me. If it had been .125, .200, .167 or .250 per revolution it would be an whole number of threads per inch. I don't even see a metric pitch that would come out to .150" per revolution. So what was their plan? I can hardly imagine setting up manufacturing with a component that actually requires an orphan number of threads per inch or an uneven mm pitch.

brian Rupnow
06-19-2015, 07:21 PM
And that, my friends, is a beautiful thing!! Everything so far is going according to plan. I have to drill a few holes in the side of the cabinet to attach it to the stud beside it to give the stand some more stability. (These China stands are sufficient to hold up the mill, but they are pretty damned wobbly when you have a 500 pound mill setting on top of them)---to say nothing of top heavy. I don't want my epitaph to read "Here lies Brian, crushed to death by his own milling machine that toppled over on him!!" :eek::eek:The only comment I have on this work so far, is that the steel in the base of those China stands is harder than the Devil's horn. It appears to be made from the same material as old bed rails that I have "re-claimed" for projects. I almost gave myself a hernia drilling eight 5/16" holes thru the base to attach my welded sub base. I have to disassemble everything and paint my welded sub-base with grey Tremclad (rust resistant) paint.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/MILL%20CABINET%20IN%20PLACE%20002_zpswj9d32rl.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/MILL%20CABINET%20IN%20PLACE%20002_zpswj9d32rl.jpg. html)

brian Rupnow
06-20-2015, 08:50 PM
My apologies to all who were following the build thread on this engine. I know it has segued into a topic about installing a new milling machine, but such is the nature of home shop machining. I promise--I will get back to the engine build as soon as I have the new mill all sorted out.---Brian

brian Rupnow
06-21-2015, 04:39 PM
So there we have it, girls and boys!! The "hole in the wall" has been transformed in to "The Mill Alcove!!". I had hoped to get a first coat of paint on it today, but have to wait overnight for the acrylic caulking compound to dry. The floor has been drilled and two concrete anchors installed and the side of the cabinet has been drilled so I can lag screw it to the near side stud.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/HOLE%20IN%20WALL%20FINISHED%20002_zpsltpxdd57.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/HOLE%20IN%20WALL%20FINISHED%20002_zpsltpxdd57.jpg. html)

brian Rupnow
06-22-2015, 03:22 PM
The machine shop is as ready as it can get for the new mill-----but------I have decided to set the mill up in my main garage because--I need the mill to make the brackets to mount the DRO. I can not put the mill into the shop until the DRO's are mounted because of very little access to the back of the machine in it's final destination. To add to the confusion, the Tee slots are a different size than my old mill, so I have to make new keys for the bottom of two vices and my rotary table. I bolted a 2 x 4 to the underside of the cabinet/base in the area that would set on the bottom sill plate in my machine shop wall, and that let me install 4 concrete anchors to stabilize things. My DRO's were supposed to arrive today from UPS, but I just got notified they have been held up at Canadian Customs and won't be delivered until tomorrow. What a crock!!! That's another chunk of money added onto everything else. Maybe they are looking for opium in the DRO box!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/MILL%20SET%20UP%20IN%20GARAGE%20002_zpsv60rtgpc.jp g (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/MILL%20SET%20UP%20IN%20GARAGE%20002_zpsv60rtgpc.jp g.html)

brian Rupnow
06-23-2015, 07:22 PM
My 2 axis DRO kit from Dropros arrived today. Everything seems to have survived the trip from California in good condition, and the items in the kit appear to be of very high quality. There is a good installation manual, users manual, and a CD which I haven't had a chance to look at yet. Everything was packed in one cardboard box with what seems to be about 20 cubic foot of Styrofoam popcorn. Right now, after having opened all of the packages to inspect for shipping damage, and a quick look thru the installation manual, it seems a bit overwhelming.---I am thinking "Rocket scientist required" but I'm sure that after I have a bit of time to familiarize myself it won't be quite so daunting. I've lost track of my total cost now, but it is getting close to $1000----I will know better after I have a chance to plow thru my Visa bill. ---Brian

Paul Alciatore
06-24-2015, 12:29 PM
Whenever I buy a machine I always look at the dials and the screws. This is a basic spec.

One of the worst and most common offenders is the round column mills sold by almost everybody. They have true inch screws with the proper dials, reading in thousandths, but the spindle feed is METRIC. 25.4 turns to the inch. WHY??? My guess is replacing a metric screw for the table is an easy job: new screw, new nut, new dial and done. But the down feed for the spindle uses a worm drive and they just didn't want to do two versions of that. So the buyer is stuck with a dial that reads false thousandths. This shows that you can't even go by the published specs.




This is really an injustice. Is there no possibility of returning the mill?

Paul Alciatore
06-24-2015, 12:40 PM
It is 6 2/3 TPI and just as easy to cut as a 10 or 8 TPI.



The leadscrew setup for that is a puzzle to me. If it had been .125, .200, .167 or .250 per revolution it would be an whole number of threads per inch. I don't even see a metric pitch that would come out to .150" per revolution. So what was their plan? I can hardly imagine setting up manufacturing with a component that actually requires an orphan number of threads per inch or an uneven mm pitch.

Paul Alciatore
06-24-2015, 12:52 PM
I just read completely through this thread for the first time. It looks like a great project and I am waiting impatiently for the final result. I hope you can post a video of it operating soon.

It was discussed a long time ago, but I wanted to add something about the discussion on piston material. It was observed that most pistons were CI or aluminum and some wondered about the use of steel. This is just an observation, but I too have observed the materials that pistons are made from and it seems to me that the manufacturing process is a big influence there. It makes perfect sense for larger pistons to be made from castings to avoid material waste. So CI (cast iron) and cast aluminum come readily to mind as the first candidates. For smaller engines, like model aircraft engines, I have seen steel used and there was no apparent difference in their performance. With those small sized pistons there is a lot less material loss and they can avoid the expense of the casting process. I am not an IC engine expert, but it would seem to me that the manufacturing concerns are one of the most important factors in choosing the piston material.

Here, with an aluminum cylinder, I would think that steel would be a good choice for the piston. Of course, the cylinder will wear the most with this combination.

brian Rupnow
06-24-2015, 07:25 PM
Paul---I have been thinking of that in the back of my head, and I'm still not certain. I am pretty sure I will use a Viton ring, and the material choice for the piston is going to come down to either steel or cast iron, possibly even bronze. It is a slow revving engine, so I'm not overly concerned about the mass of the piston. I always run a bit of 2 cycle oil with the gas to lubricate the Viton ring, so wear shouldn't be an appreciable factor. I won't run aluminum on aluminum, too much chance of it galling.-----Brian

brian Rupnow
06-24-2015, 08:40 PM
So, what do you do when you have a chip making, oil splattering milling machine in one bay of your garage, and a hot-rod with a white convertible top and tonneau cover in the other bay?---Answer---you improvise. I have a collection of various tarps that I have accumulated over the last 40 years, and an overhead beam in my garage.--I'm certain that I probably picked the nastiest, dirtiest tarp of all, but it will get the job done on a temporary basis. I need the milling machine to make the brackets to mount the DRO's in the coming week. As a point of interest, you can see the big power hacksaw that I built about 45 years ago in the foreground. I was building "wrought iron" railing and room dividers as a sideline back then. The saw will handle anything up to 5" diameter. I only use it occasionally now, and for cutting drill rod.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/TARP%20IN%20GARAGE%20003_zps3xrdyupa.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/TARP%20IN%20GARAGE%20003_zps3xrdyupa.jpg.html)

brian Rupnow
06-25-2015, 07:51 AM
Morning is off to a bad start.---Went to machine a bracket and found that the BusyBee 1/2" and 3/8" collets with R8 taper do not fit into their mill which is designed for R8 tooling. Waiting for 8:00 to get to the bottom of this. The chuck and boring head fit fine, just not the collets. These collets do not have the internal seat for the shank of the endmill to set up against either, like my MT2 collets had. Perhaps I am missing something here, but right now I'm righteously ugly!!!

Toolguy
06-25-2015, 01:12 PM
R8 collets don't have an internal seat like some others. It's not normally a problem. Sometimes on cheap collets the band at the top is part of a thou. too big and has to be sanded down. The dim. should be .950" +0, -.0005. That depends on the accuracy of your particular mill spindle though. I'm thinking the spindle is OK since the other tools fit.

brian Rupnow
06-25-2015, 06:38 PM
The plot thickens--I called BusyBee in Barrie, raised merry Hell, and told them I was coming over to return the collets and buy dedicated end mill holders. When I got there, everybody was standing around looking non-plussed, and told me that they have the identical machine to mine still on the show room floor, and that neither there collets NOR there end mill holders would fit in the spindle of their machine. I was then referred to corporate head office in Toronto, and told I should dismantle my new machine which has never been used yet, and back off the screw in the spindle housing. At that point I got quite vocal and began threatening law-suit. After getting no joy at all from Busy Bee, I decided that perhaps it would be wise to go to a REAL tooling shop and borrow a REAL cutting tool holder with an R8 shank.---I did---and it doesn't fit my mill either. I am now setting in my office, measuring the slots in the R8 shanks, and seeing that on the ones that do fit my mill, the slots are 0.200" wide and 0.100" deep. The ones that don't fit have a slot 0.150" wide and 0.060" deep. I am going to sort this out, but it's a pain in the a$$.

RichR
06-25-2015, 09:39 PM
Hi Brian
Here's an R8 drawing Evan posted a few years ago:
http://bbs.homeshopmachinist.net/threads/31945-R-8-Dimensions?p=398920#post398920

brian Rupnow
06-26-2015, 12:15 PM
I have removed the pin. I have complained loud and long to all levels of management at BusyBee. They are all aware that there may be a problem with ALL of the CX601 mills across Canada. I get very upset when something like this happens, but I have to remember, BusyBee, with whatever problems they may have, have given me good service over the past six years. I get mad, as anybody would in a similar situation, but I don't want to cut off my nose to spite my face!!! With the pin removed, the mill will take all of my different equipment with R8 shanks. I have made my first cuts in cold rolled steel with the new mill. It is no longer virgin. These are new machine growing pains. They definitely do not make me happy, but they don't make me want to label the machine as junk either. My previous smaller mill was from BusyBee, and it served me faithfully for six years.

brian Rupnow
06-26-2015, 03:14 PM
The mill is up and running. My God, what a powerful monster it is compared to my old small mill. I was side milling and end milling in steel, taking cuts twice as deep as my old mill and it never even grunted. I'm getting off to a rocky start here, but I think it's going to be okay. Tomorrow I start doing some layout work for the DRO brackets. I will probably model the brackets in 3D cad and lay out the areas of the mill where the DRO's attach. There aren't that many brackets to be made, only 3 from what I can tell right now, and they are all associated with the Y axis scale and reader head. The X axis scale just attaches directly to the rear of the table. I have a lot of "other stuff" going on this coming week, but hope to make good headway with the scales.---Brian

brian Rupnow
06-26-2015, 08:45 PM
Now that I have totally polluted this build thread with ramblings about my new mill, I'm rethinking things. The oscillating engine will get finished, but I am being asked on a number of forums to go into more detail about the mill and the installation of the DRO package, and I can see a lot more postings being required to address all the mill related questions. I am going to leave this thread now, and pick it up again once all my work on the mill and the installation of the DRO kit and relocated head lifting handle are completed. My new thread will be titled "CX601 Milling Machine".

brian Rupnow
07-19-2015, 03:17 PM
Now, where the heck was I when the lights went out two months ago---I have a big tin can full of parts, and I'm certain that I would be much happier if they were all bolted to something to kind of make sense. I will now try and get some fun out of my new mill, and whittle out a baseplate.---Brian
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/BASEPLATE-OSCILLATING_zpsjlwfnkxi.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/BASEPLATE-OSCILLATING_zpsjlwfnkxi.jpg.html)

brian Rupnow
07-20-2015, 11:57 AM
Well, it doesn't look THAT much more impressive with all the pieces assembled on the baseplate.--In the background you can see the slice of 1" x 5 1/2" diameter bronze that is destined to become a flywheel. And yes, I do have the gearblanks turned to diameter to cut gears from. Also, in the background, you can see the 3/4" x 1 1/2" aluminum "riser bars" that will lift the baseplate up high enough that the flywheel doesn't touch the tabletop.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/ASSEMBLED%20ON%20BASE%20PLATE%20001_zpsx6iojfpt.jp g (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/ASSEMBLED%20ON%20BASE%20PLATE%20001_zpsx6iojfpt.jp g.html)

brian Rupnow
07-21-2015, 03:48 PM
There--I think that is a definite improvement with the risers in place under the base!!---And yes, those are the points and condenser I will use on the engine, displayed along with their part numbers. I purchase them from PartSource, an automotive supply house here in Barrie. The parent company is BWD automotive in Long Island, New York.--They are originally intended for use on some Chrysler automobile.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/POINTS-CONDENSER-BASE%20AND%20RISERS%20001_zpsuuzffnik.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/POINTS-CONDENSER-BASE%20AND%20RISERS%20001_zpsuuzffnik.jpg.html)

brian Rupnow
07-22-2015, 08:41 PM
I'm about to head off into gear cutting territory, but I have a question wiggling around in the back of my mind about the aluminum cylinder. I like it. It's beautiful----but I don't know if it will stand up to the combustion process or not. If not, I will put in a cast iron liner, to take the bore down from 1" to 7/8". My question is, can cast iron be turned to have a 1/16" wall, or is that too thin to machine comfortably? The liner would only be 2" long. I have turned a few cast iron cylinders, but have very little experience with liners.---Brian

TGTool
07-22-2015, 09:07 PM
I've machined cast iron to a 1/16" wall so I don't think that should present you any real problems. You can work out whether to bore to size then work down the OD on a mandrel or the reverse. And you could do OD to size, ID undersize, install in cylinder then whittle it back in situ.

You've got skills and ingenuity, Brian, just go for it if it comes to that.

JCHannum
07-23-2015, 07:11 AM
If a thicker liner is fabricated, installed and then bored to final size in situ, the thin wall should not present a problem. However, if you use a Viton piston ring, the aluminum bore should hold up quire well.

vpt
07-23-2015, 08:38 AM
Many of lawn mowers and outboard motors just use aluminum cylinders without any problems. I am sure your aluminum cylinder will be fine.

Seeing 7 pages I thought I might see a video towards the end like I normally do with your threads. Then I saw 3 pages of a new mill. lol

Congrats on the new mill! Looks like a nice upgrade from your old small mill. I must have missed it, are you keeping your old mill for a backup or something? I have always wanted a second smaller version work shop in my basement for the winter months.

brian Rupnow
07-23-2015, 08:53 AM
Many of lawn mowers and outboard motors just use aluminum cylinders without any problems. I am sure your aluminum cylinder will be fine.

Seeing 7 pages I thought I might see a video towards the end like I normally do with your threads. Then I saw 3 pages of a new mill. lol

Congrats on the new mill! Looks like a nice upgrade from your old small mill. I must have missed it, are you keeping your old mill for a backup or something? I have always wanted a second smaller version work shop in my basement for the winter months.

The entire mill saga is covered under post titled "CX601 MILLING MACHINE"

CarlByrns
07-23-2015, 05:15 PM
Many of lawn mowers and outboard motors just use aluminum cylinders without any problems. I am sure your aluminum cylinder will be fine.


Outboards and power equipment engines usually have iron or steel liners while smaller (or cheaper) power equipment engines (big-box store weed trimmers) use a chrome plated aluminium bore. Once the chrome is gone, so is the engine.

vpt
07-23-2015, 09:02 PM
Outboards and power equipment engines usually have iron or steel liners while smaller (or cheaper) power equipment engines (big-box store weed trimmers) use a chrome plated aluminium bore. Once the chrome is gone, so is the engine.



I remember boring many of small engines in small engine class that left only aluminum for the piston to ride on.

I see tons of plain aluminum cylinders in small motors.

brian Rupnow
07-24-2015, 09:34 AM
It's been a very "Geared up" morning hear!! I cut the two gears I require for the oscillating engine, and the four gears required for the flathead engine I built. Some fellow out in central USA built the Rupnow side valve/flathead engine and then realized he had no way to make the gears for it. I still have some parting off to do, and some clean up, but these are the first gears I have cut with my new mill.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/ALL%20GEARS%20CUT%20001_zpsekjlk8fp.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/ALL%20GEARS%20CUT%20001_zpsekjlk8fp.jpg.html)

brian Rupnow
07-24-2015, 02:15 PM
I just cut my first cam using the "Chuck Fellows Method"---(Google chuck fellows cam cutting youtube) and I must say, it works a treat!!! Thank you Chuck!!!--and---Since I haven't had time to rig a permanent depth stop on this new mill, I thought you might like to see the "Hokiest Depth Stop Ever"---But it worked very well. By the way--there are two gears on that piece of steel. I just haven't parted them off yet.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CAM%20CUTTING%20FELLOWS%20STYLE-2%20002_zpsdyirunsn.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CAM%20CUTTING%20FELLOWS%20STYLE-2%20002_zpsdyirunsn.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CAM%20CUTTING%20FELLOWS%20STYLE-2%20001_zps6prgbbzm.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CAM%20CUTTING%20FELLOWS%20STYLE-2%20001_zps6prgbbzm.jpg.html)

brian Rupnow
07-24-2015, 05:03 PM
We've got gears. Lots and lots of gears. In fact, we've got a whole freakin days worth of gears!!! I have 8 hours in these gears!! I know that the two on my oscillating engine mesh properly---I've tried them. I haven't made up a test jig to check the mesh on my other four gears that are going to a guy in USA. I will make a test jig to check them tomorrow. The 3 jaw chuck on my lathe is about .0015 out of true center. The 3 jaw chuck on my rotary table tends to have a wondering true center. I know there is some "forgiveness' built into the design of these small spur gears, but I never feel really good about them until I have drilled a piece of scrap and inserted 4 short pieces of shaft to mount the gears on and actually turn them to see what is going to happen. Sometimes they are perfect. Sometimes they need an application of 600 grit carborundum paste and spun for 15 minutes with the electric drill to get rid of any bind caused by eccentricity in my set-ups.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/LOTS%20OF%20GEARS%20002_zpskmttu2p3.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/LOTS%20OF%20GEARS%20002_zpskmttu2p3.jpg.html)

MrSleepy
07-24-2015, 05:14 PM
Since I haven't had time to rig a permanent depth stop on this new mill, I thought you might like to see the "Hokiest Depth Stop Ever"---But it worked very well. By the way--there are two gears on that piece of steel. I just haven't parted them off yet.



This guy made a depth stop on a mill similar to yours ...

http://bbs.homeshopmachinist.net/threads/57526-Quill-stop

:)

brian Rupnow
07-24-2015, 06:15 PM
This post has nothing to do with the current engine build.---However--It does show 4 gears I made today mounted on a test jig, to see if they mesh properly without any binding. This time I was lucky--Smooth as silk!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/GEARS%20ON%20TEST%20JIG%20001_zpsy56wm0yq.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/GEARS%20ON%20TEST%20JIG%20001_zpsy56wm0yq.jpg.html )

vpt
07-24-2015, 06:50 PM
Thats allot of gears!

brian Rupnow
07-25-2015, 11:40 AM
This morning I made up the big and for the con rod, and the con rod itself, though as yet I don't have a piston on the other end of the rod. I also took the time to read the manuals and figure out how to find the center of a hole using my new DRO system. I might finish a piston today, but then I might not---It"s getting awfully nice outside, and I was in the shop for 10 hours yesterday----
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CON%20ROD%20002_zpsow1ime7c.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CON%20ROD%20002_zpsow1ime7c.jpg.html).

Cuttings
07-25-2015, 12:09 PM
Good morning Brian
I was just sitting here looking at the picture in your last posting and a thought came to me.
Would it be possible to make a double acting engine from this design?
Valving would be the tricky part. You would need some good sealing on the connecting rod.

brian Rupnow
07-25-2015, 12:56 PM
Larry--It has been done before. The problem is, that with internal combustion engines the carbon deposits build up on the rod where it passes thru the gland and wears out the seal very rapidly.---Brian

Cuttings
07-25-2015, 05:35 PM
Good point, better leave that one to run on steam.

brian Rupnow
07-25-2015, 06:21 PM
As with all newly assembled engines, this one was very stiff when all the bolts were tightened down. I have come to expect that, so part of this afternoon was spent trimming a bit here, stretching bolt holes a bit there, until finally it would turn over by hand. Of course a large part of the issue is that there is no convenient "handle" to turn the engine over with. I'm down to the point where most of the large pieces are finished, but I think I will make a start on the flywheel tomorrow, more to have something to actually grab onto to turn the engine with than anything. I have decided not to put the cooling vanes in the flywheel---at least for now---.

brian Rupnow
07-26-2015, 10:24 AM
I just about got ahead of myself here.--I need a piston before I move on to the flywheel.---And man, what a big piston it is!!! I used bronze because it has good lubricity characteristics, and because that is what I had. I am not concerned about the mass, as it is a slow revving engine anyways.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/BRONZE%20PISTON%20001_zps1digoame.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/BRONZE%20PISTON%20001_zps1digoame.jpg.html)

brian Rupnow
07-27-2015, 01:30 PM
Now THAT my lads, is a flywheel!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/FLYWHEEL%20FINISHED%20001_zpsusv1ci9t.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/FLYWHEEL%20FINISHED%20001_zpsusv1ci9t.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/FLYWHEEL%20FINISHED%20002_zpsicirbwi0.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/FLYWHEEL%20FINISHED%20002_zpsicirbwi0.jpg.html)

brian Rupnow
07-30-2015, 03:31 PM
A video for your entertainment.--No, the engine isn't running yet, but it is taking a major step forward.---Brian
https://www.youtube.com/watch?v=S8pbHkPGDRo&feature=youtu.be

vpt
07-30-2015, 07:07 PM
Thanks for the video! Coming along very nice!

Have you ever used ball or needle bearings in place of plain bearings?

brian Rupnow
07-30-2015, 08:37 PM
Yes, I have. They work well, but are not a necessity for these small engines. Most ball bearings do allow a slight degree of angular offset, which plain bushings do not. A nice way to build a small engine with ball bearings is to bore the housings which accept the bearings slightly oversize. Then on final assembly, coat the outside of the bearing shell with Loctite and let the crankshaft determine the final position of the bearings. After 24 hours when the Loctite has set, the engines will spin with no bind at all, as long as the crankshaft is truly straight.--There is a caveat about needle bearings that many people don't realize---They don't usually have an inner race, so the crankshaft must be hardened to run them, otherwise they tear up the shaft under load conditions. If you order them with an inner race, then the outer housing diameter becomes much larger, to the point where they are hard to fit into a small engine.-I did install a set of needle bearings on one of the first hit and miss engines I built, and although the engine never sees any real load, the needle bearings are very noisy on an open crankcase engine.--Brian

brian Rupnow
07-31-2015, 09:06 AM
It looks like I'm down to carburetor time!!! This carb has only two largish pieces, and requires no throttle, so it shouldn't be as complex as many carb's I have built. The only thing I'm not really thrilled with is that both carburetors pieces are going to require 4 jaw work. I can do 4 jaw work, it just takes me an inordinately long time to get set up properly. However, it's not hard work---It's just picky work.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/ASSY%20OF%20CARBURETOR--OSCILLATING_zpsm72z2dkc.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/ASSY%20OF%20CARBURETOR--OSCILLATING_zpsm72z2dkc.jpg.html)

brian Rupnow
07-31-2015, 07:17 PM
A minor change to that yellow valve body--(Which doesn't move with the rocking cylinder.) In the original version, the exhaust blew right out into the area where I intend to put a vertical cylindrical gas tank. Since the idea of hot exhaust blowing onto the side of a gas tank disturbs me a little, I have reconfigured the round boss to a new shape and put in an exhaust pipe which blows out at 90 degrees to the original exhaust path. Of course, this means that I have to plug the drilled exhaust port, but since i intend to silver solder the exhaust pipe in place, I can run a little more solder to hold the plug in place.---And as an added benefit, that also gives one less 4 jaw set-up than the original plan.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/ASSEMBLY%20WITH%20EXHAUST%20PIPE_zps9ybxnyvd.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/ASSEMBLY%20WITH%20EXHAUST%20PIPE_zps9ybxnyvd.jpg.h tml)

brian Rupnow
08-02-2015, 10:26 AM
We have an exhaust valve body completed.--I'm very proud of this simple piece, because the main block had two 4-jaw set-ups required, and I manage to get both of them right. The exhaust pipe is soldered into place, as well as the cover for the cross drilled exhaust hole---(The cover kind of disappeared during the silver soldering process, but that's okay. It's not obvious on the finished piece). I have a bit of clean up and polishing yet to do on the part, but the exhaust valve body is essentially finished. Next up comes the intake valve body/carburetor, which bolts onto it.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/EXHAUST%20VALVE%20BODY%20COMPLETED%20001_zpsfvtdis v9.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/EXHAUST%20VALVE%20BODY%20COMPLETED%20001_zpsfvtdis v9.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/EXHAUST%20VALVE%20BODY%20COMPLETED%20002_zpshnqest v3.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/EXHAUST%20VALVE%20BODY%20COMPLETED%20002_zpshnqest v3.jpg.html)

brian Rupnow
08-03-2015, 07:50 AM
Talk to me people--If you find this thread interesting at all, say Hi. I am coming into the final stages of this build, and although I post on three forums, it has mostly gone silent out there.I know folks are watching the thread, I see the post count going up each day.It's lonely out here!!!----Brian

Lew Hartswick
08-03-2015, 08:15 AM
That set of gears look a bit MASSIVE for the size of the engine. :-)
...lew...

brian Rupnow
08-03-2015, 08:54 AM
Leaping Lizards, Batman--Check out the intake valve/carburetor housing. That was my second part that needed to be done in the 4 jaw chuck. I may not like 4 jaw chuck work, but I certainly am improving at it. There are very few parts remaining to be made before I'm ready to run this baby!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/FINISHED%20CARBURETOR%20MAIN%20BODY_zpszo3cbucl.jp g (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/FINISHED%20CARBURETOR%20MAIN%20BODY_zpszo3cbucl.jp g.html)

Stepside
08-03-2015, 09:30 AM
Brian

I have been watching this engine from when you started with some sketches. The most impressive part of the whole project is your presentation as you as you update your progress. If someone has never gone from an idea, to a sketch, to a drawing, to a part that has to fit and work with another part, they won't understand what you have done.

The Four Jaw chuck will become your friend and you will find it easier to use it than to change back and forth with the Three Jaw.

Keep up the good work.

Pete

davidwdyer
08-03-2015, 09:54 AM
Hey Brian,

I'm watching, as I'm sure others are, and really enjoy the threads. Keep 'em coming.

hitnmiss
08-03-2015, 10:57 AM
Watching here!

aostling
08-03-2015, 01:30 PM
Brian,

How about speed control? There must be a governor somewhere, but I can't find it.

RichR
08-03-2015, 02:51 PM
Brian,

How about speed control? There must be a governor somewhere, but I can't find it.

The motor did have a power boost mode, but then Brian decided to aim the exhaust away from the fuel tank.

Rustybolt
08-03-2015, 02:55 PM
Talk to me people--If you find this thread interesting at all, say Hi. I am coming into the final stages of this build, and although I post on three forums, it has mostly gone silent out there.I know folks are watching the thread, I see the post count going up each day.It's lonely out here!!!----Brian


Shhh! I'm trying to follow a project, here.

woodenbird
08-03-2015, 03:23 PM
Brian,
I have been following your design and build with great interest. Please keep up the posts.
Thanks
Glenn

brian Rupnow
08-03-2015, 03:23 PM
Brian,

How about speed control? There must be a governor somewhere, but I can't find it.

Look in post #146 and 149--Just inside of the crankshaft support bearing on the flywheel side you will see the governor and the brass spool it slides back and forth to move the hit and miss lever in and out of contact with the exhaust valve push-rod. It is a very strange looking centrifugal governor, not at all like a flyball governor. That is the speed control.

brian Rupnow
08-03-2015, 04:05 PM
There must be something worse than having to make the same part twice, but right now I can't think of what it is!!! In the air-inlet of the carburetor you will now see a carburetor jet setting at 90 degrees to the air-flow, with a shiny #6-32 hex nut on one end and a smooth 0.175" diameter on the end facing away from the engine to hook my fuel line to. The needle valve, which isn't made yet, screws into the threaded end of the carburetor jet. Laying on the base of the machine, you can see the exact same part---WHAT???---Yes, the same part, except that the .040" hole drilled full length of it on the center, decided to take a turn for the worse and exit thru the side of the damned thing instead of out the other end. This happens to me sometimes. As I get more and more machining experience, it happens less often, but it still makes me say bad things and think evil thoughts when it does happen!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/CARBURETOR%20JET%20FINISHED%20001_zpsd6ufjee6.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/CARBURETOR%20JET%20FINISHED%20001_zpsd6ufjee6.jpg. html)

brian Rupnow
08-03-2015, 06:42 PM
I have reached that wonderful turnover point, where I have less pieces to make than are already made. I just printed off the last few drawings, and it looks like I'm down to two valves, two valve keepers, a needle valve, the hit and miss trip lever, and a gas tank. If I don't run into problems with leaky valves, I should have a runner before the end of August. Thank you to all who said Hi. It always happens at about this point in a build that has went on for a while--I start to wonder if anybody is following the build. I know people are looking because I can see the number of visits to the topic going up, but I guess my confidence needs a boost. It certainly makes me feel good when people take the time to stop by and say Hi.---Brian

Toolguy
08-03-2015, 06:58 PM
Hi Brian-
I follow all of your builds. They are some of the most interesting threads on here. I think you're doing a great job! Even though things may wander off the main path occasionally, I find the meanderings interesting as well. I hope you are liking your new mill - it looks like a good one. The drawings and pictures are clear and add much to the content. As always, thanks for taking us along for the ride!

brian Rupnow
08-03-2015, 08:14 PM
Thank you for the kind words, Toolguy. I really do like the new mill, and I love the DRO set-up. I wish now that I had bought a 3 axis DRO. The mill has it's own small "built in" digital DRO for the Z axis, but it is not illuminated and is rather difficult to see. I'm glad that you find my posts interesting.---Brian

ulav8r
08-03-2015, 09:35 PM
the same part, except that the .040" hole drilled full length of it on the center, decided to take a turn for the worse and exit thru the side of the damned thing instead of out the other end.

Clumsy Baxxxxxxxxxx. I always read all your posts but don't believe in running up my post count just to say "looks great".

Stepside
08-03-2015, 10:19 PM
Brian

Just a "shot from the hip" idea. Because small drills like to wander, sometimes I drill with a bit that is larger and "shim" the bore with brass model-makers tubing. The large drill is sized to the OD of the tube. The tube is held with Loctite or silver braze. If the right tube size is available for your needs you will gains a very smooth bore as an added bonus. By model-makers tubing, I am referring to the tubing sold in 12 inch lengths at the hobby store.Because each size is a fit in the next larger or smaller diameter, it is possible to use an even larger drill.

Pete

brian Rupnow
08-04-2015, 07:28 PM
Nothing really exciting or high-tech to post about tonight. Just a couple of valve spring keepers. The intake valve keeper is reamed to .125", the exhaust valve keeper is threaded #5-40 (And yes, that IS a hex machined onto the back side of it.). I picked up the springs at Brafasco while I was running all over town getting quotes for a customer, and managed to work 6 hours in my office on a design job.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/VALVE%20KEEPERS%20001_zpstnee0ol4.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/VALVE%20KEEPERS%20001_zpstnee0ol4.jpg.html)

brian Rupnow
08-04-2015, 07:31 PM
Brian

Just a "shot from the hip" idea. Because small drills like to wander, sometimes I drill with a bit that is larger and "shim" the bore with brass model-makers tubing. The large drill is sized to the OD of the tube. The tube is held with Loctite or silver braze. If the right tube size is available for your needs you will gains a very smooth bore as an added bonus. By model-makers tubing, I am referring to the tubing sold in 12 inch lengths at the hobby store.Because each size is a fit in the next larger or smaller diameter, it is possible to use an even larger drill.

Pete

Stepside--Thanks. I have used that brass tubing trick and it works great if there is room for it. This time the greatest part of the outside diameter of the jet was only 0.135", and had two different size bores in it.

brian Rupnow
08-06-2015, 06:53 PM
I just had a very exhausting time this afternoon!! Okay, I know, horrible pun!! I turned the exhaust valve from cold rolled 1/2" diameter steel, and left it attached to the parent metal until I had a chance to lap it into the valve seat with #400 then #600 lapping paste. I know it is setting on a tub of 320 grit, but I didn't actually use any of that---it was just holding up the valve for a picture. After trying the "Blow your guts out thru the exhaust pipe test" to convince myself that the valve was really going to seal, I cut the valve away from the 1/2" cold rolled rod and installed it in the exhaust valve body, along with the spring, keeper plate, and lock nut. I left about .025" clearance between the locknut and the brass valve lifter, when the lifter is not "up" on the cam.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/EXHAUST%20VALVE%20002_zpshfhncpk3.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/EXHAUST%20VALVE%20002_zpshfhncpk3.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/EXHAUST%20VALVE%20003_zpsobbtxjhs.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/EXHAUST%20VALVE%20003_zpsobbtxjhs.jpg.html)

brian Rupnow
08-06-2015, 07:02 PM
Dang!! I didn't notice how crooked that lock nut was setting until after I had posted the picture!!:p I took it off, turned it around, and put it back on. It's setting straight now, but you're going to have to take my word for it.

brian Rupnow
08-07-2015, 10:11 AM
I found a precious hour this morning to whittle out an intake valve, lap it, and install it in the intake housing. I still have to make paper gaskets to go between the intake and exhaust housings and between the exhaust housing and the pillar it bolts against. I have never had much luck with the "gasket in a tube" stuff by Permatex nor anyone else.---Perhaps that is because I end up taking things apart and putting them back together again about 40 times before I'm actually finished!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/INTAKE%20VALVE%20001_zpsfxwzzc3v.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/INTAKE%20VALVE%20001_zpsfxwzzc3v.jpg.html)

brian Rupnow
08-08-2015, 04:15 PM
And today we have the needle valve, complete with needle silver soldered to adjusting knob. It works.--I can blow a stream of air through the jet from the gas line end with my mouth firmly puckered around the fuel inlet.---As I close the needle valve with my fingers, it gets harder and harder to blow until finally it seals completely. Tomorrow it will be time to build gaskets.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/NEEDLE%20VALVE%20002_zps4tnd7xkt.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/NEEDLE%20VALVE%20002_zps4tnd7xkt.jpg.html)

brian Rupnow
08-08-2015, 06:37 PM
Wife is having a nap---I kept working!!! Gaskets are made and installed. Valve timing is set. When spun by hand, I am getting a bounce back on compression stroke. Not a lot of bounce back, but it's there. Holy Cow---All that's between me and a running engine is the starter ring which bolts to the flywheel to let me engage my variable speed drill as a starter!!! I can borrow a gas tank of one of my many other i.c. engines.---Getting excited now!!!

Black Forest
08-09-2015, 05:37 AM
Wife is having a nap---I kept working!!! Gaskets are made and installed. Valve timing is set. When spun by hand, I am getting a bounce back on compression stroke. Not a lot of bounce back, but it's there. Holy Cow---All that's between me and a running engine is the starter ring which bolts to the flywheel to let me engage my variable speed drill as a starter!!! I can borrow a gas tank of one of my many other i.c. engines.---Getting excited now!!!

Eagerly awaiting the test run on gas! I bet it will be like a shaper meaning the wobbly cylinder will have you standing there mesmerized!

brian Rupnow
08-09-2015, 05:42 PM
Today's offering to the Machine Gods consists of a starter hub, the part which fits into my variable speed drill to engage the starter hub, and a mounted condenser. I have set the valve timing and the ignition timing. The ignition points and cam are hidden in behind the hub of the flywheel.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/STARTER%20HUB%20AND%20CONDENSER%20001_zpskcvpgp4k. jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/STARTER%20HUB%20AND%20CONDENSER%20001_zpskcvpgp4k. jpg.html)

aostling
08-09-2015, 06:57 PM
Today's offering to the Machine Gods consists of a starter hub, the part which fits into my variable speed drill to engage the starter hub, and a mounted condenser. ...

Will the engine not start by simply spinning the flywheel by hand?

brian Rupnow
08-09-2015, 07:05 PM
Now is the difficult time. The engine is ready to run. I have gas tanks which I can "borrow" from many of my other engines. The issue is that this type of engine has no throttle. It is designed to run "wide open" or "full throttle". The device which controls the RPM is the hit and miss lockout lever and the centrifugal governor. There is nothing that quite compares to starting one of these engines without the governor set up in place. First you wonder if it will start and run. Then, in one terrifying burst you wonder if you will be able to shut it off before it over revs and explodes. This all happens in a matter of nano-seconds, and it scares the crap out of you. I will make the lockout lever and install it before I try to start this engine. There is a spring required to control the centrifugal weight, and I think the spring I currently have in place is too light. I went to Brafasco and raided their spring collection, but the only spring that would actually fit the hole prepared for it is the spring out of a ball point pen. The strength of this spring is critical to the way the engine runs. If the spring is too light, the governor weight will fly out and engage the exhaust valve lifter at too low an rpm, and the engine won't have enough speed to keep running. If the spring is too strong, the governor weight won't fly out and engage the exhaust valve lifter until the engine reaches warp speed. And the only way you will know if the spring is too light or too strong is to start the engine and find out!!! At least I have progressed from having to pull the spark plug wire off and risk electro-shock therapy. I have a kill switch on my "power box" which has the 12 volt coil in it.

brian Rupnow
08-09-2015, 07:09 PM
Will the engine not start by simply spinning the flywheel by hand?

Sometimes, if your stars are in perfect alignment, they will. More often than not, you can flip that damned flywheel until your wrist is about to fall off and they won't start. Have you ever built an i.c. engine of any kind? Have you ever built and tried to start a brand new hit and miss engine that has never ran before? If you have, I doubt that you would be asking this question.---Brian

RB211
08-09-2015, 07:29 PM
Well, we all can't wait to see the video of the first run!

Cuttings
08-09-2015, 07:46 PM
Brian - there is one difference between you and the rest of us patiently waiting to see the new engine run.
We are far enough away to duck if she tries to put something into orbit.
But I am sure I speak for most fellows on hear that we have a lot of confidence in your ability to get it right and we should worry about having to duck.

brian Rupnow
08-09-2015, 08:01 PM
I don't normally admit to it---but---I was just going over the layout of that lock-out lever on my cad system (Thank God I can animate stuff and move it through the motions the finished parts will move in)---and I discovered a mistake in the positioning of the roll pin in the exhaust valve lifter. It was MY mistake.--I fixed it. It is nice to discover these things BEFORE you actually make the part!!!

aostling
08-09-2015, 08:04 PM
Have you ever built and tried to start a brand new hit and miss engine that has never ran before?

No, and I now appreciate what a stressful operation the first start might be.

Considering how critical it is, the optimum governor spring constant K (lb/in) could be calculated, for whatever desired RPM you want the engine to run at.

brian Rupnow
08-09-2015, 09:24 PM
Aostling---You and I have both seen this type of engine start with "a flick of the wrist". Some of my engines will, after they are warmed up and everything adjusted to compensate for the ambient temperature, fuel mixture, etcetera. Some folks post videos of doing exactly that, and would lead you to believe it happens every time. Either these people are light years ahead of me in their technical ability, or know some wonderful secret I have yet to discover. Trying to explain just how much is involved with the first start of a newly built engine is like trying to describe color to someone who has been blind since birth. I have had some newly built engines start right up on the very first try, but trust me---it doesn't usually happen that way.---Brian

aostling
08-09-2015, 09:47 PM
Brian,

If trial and error gets frustrating, this centrifugal force calculator might help: http://www.calctool.org/CALC/phys/newtonian/centrifugal. It will tell you the spring force required to maintain the governor mass at a given radius (of gyration) and RPM.

You could guess at the radius of gyration -- it is the distance from the flywheel axis to some point in the moving weight, further out than its centroid.

brian Rupnow
08-10-2015, 11:04 AM
So---How good are your eyes? In the first picture, the counterweight on the centrifugal governor has pivoted and swung outward from centrifugal force, causing the brass spool to slide along the crankshaft, which makes the hit and miss catch lever pivot and swing in under the 1/8" diameter split pin in the bronze valve lifter. This prevents the exhaust valve from closing, so the engine remains in the "miss" cycle as long as the engine rpm is high enough to keep the governor weight swung out like that. In the second picture, the engine has slowed down enough that the spring captured between the governor weight and the governor weight support has caused the governor weight to pivot and swing back in, which moves the brass spool the other way, thus causing the hit and miss lever to pivot the other way and swing out from under the split pin, which now lets the exhaust valve lifter follow the cam and let the exhaust valve close to build compression as the engine continues to rotate because of the flywheel. In this state the engine will then fire and start the whole cycle over again. There is some very fussy work in getting all of this to happen freely in a static position.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/HIT%20AN%20MISS%20LEVER%20002_zpsned696nh.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/HIT%20AN%20MISS%20LEVER%20002_zpsned696nh.jpg.html )
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/HIT%20AN%20MISS%20LEVER%20003_zpsrcdgdxt9.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/HIT%20AN%20MISS%20LEVER%20003_zpsrcdgdxt9.jpg.html )

aostling
08-10-2015, 11:58 AM
So---How good are your eyes?

Mine don't know what to look at. I can't tell what has shifted in the two photos.

Can you identify the pivoting counterweight? Perhaps with a a sketch, or arrows on the photo.

brian Rupnow
08-10-2015, 12:15 PM
FIRE IN THE HOLE!!!! Engine is firing, but just as I suspected, the governor spring is too weak. It fires once, goes into miss mode and stays there. The weak spring doesn't have enough strength to retract the governor weight against even a low firing rpm!!

brian Rupnow
08-10-2015, 12:16 PM
The pivoting counterweight is that thing just inside the bearing support beside the flywheel.

brian Rupnow
08-10-2015, 01:18 PM
I have a fix for this, but it will take a while. The counterweight and counterweight support bracket are exactly as designed by the original designer, Philip Duclos, and the hole for the spring is only 0.172" in diameter. I can open this up to 0.219" safely, which will allow for a larger, stronger spring. Before I modify anything though, I will go back down to Brafasco and make sure they have larger stronger springs that will fit into a 7/32" diameter hole. Then I have to remove the flywheel, the ignition cam, and the crankshaft support bearing to get the counterweight support bracket off to work on it and enlarge the hole in it and in the counterweight.

woodenbird
08-10-2015, 01:45 PM
Thanks for showing the two positions, Brian. Glad you have a relatively easy fix.

dp
08-10-2015, 05:21 PM
In the mean time can't you snap some elastic bands around it so we an all watch it run? :)

brian Rupnow
08-10-2015, 06:08 PM
I went to Brafasco and bought 3 springs that would fit into a 7/32" diameter hole in a "test piece" I had made. I got a light spring, a medium spring, and a heavy spring. I removed the governor and enlarged the hole that holds the spring to 7/32" diameter. Then I installed the medium spring (the copper colored one). For those of you who asked about the centrifugal governor, I have included shots of the governor bracket that is fixed to the crankshaft with a set screw, and the governor weight which swings out under centrifugal force to move the brass spool. You can see it before and after assembly. It pivots on a 1/16" diameter pin.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/GOVERNOR%20STUFF%20001_zpsuz6yuknu.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/GOVERNOR%20STUFF%20001_zpsuz6yuknu.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/GOVERNOR%20STUFF%20002_zpsrigt6e1v.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/GOVERNOR%20STUFF%20002_zpsrigt6e1v.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/GOVERNOR%20STUFF%20003_zps999reqdm.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/GOVERNOR%20STUFF%20003_zps999reqdm.jpg.html)

brian Rupnow
08-10-2015, 07:32 PM
EXCELLENT NEWS!!! Engine starts and runs, but medium strength spring is still a bit too light. Engine is new, and still a bit stiff, so it dies before it can go from "miss" mode back into "hit" mode consistently. I am now changing up to strongest spring, but things are really looking positive!!!

brian Rupnow
08-11-2015, 08:06 AM
No joy yet. The strongest spring does work all right (near as I can tell.) I had the engine running for short duration blasts, and grabbed the video camera a dozen different times but the engine wouldn't oblige me by staying running. I played with the ignition timing, first advancing it, then retarding it, looking for the "sweet spot" but never found it. I adjusted the carburetor needle to every conceivable position, but the best run I got was only about a two minute duration, with the engine gradually slowing down and coming to a stop. After about 50 different attempts to start the engine, I was rewarded with a rather ominous "clanking" sound every time it started. Nothing was visibly wrong that could be seen from outside the engine (and almost everything is on the outside of the engine.) The compression has improved exponentially, so the pressure caused by the engine firing has firmly seated the valves. I never reached the point where the engine "took off" and gained rpm until the centrifugal governor was activated, but I was able to activate it by spinning the engine fast enough with my 3/8" variable speed drill, so I know the centrifugal governor is working. I will pull the head off the engine sometime today and make sure that the piston isn't coming adrift from the connecting rod, and ascertain that my pressed together crankshaft hasn't slipped out of alignment.

brian Rupnow
08-11-2015, 10:20 AM
TA-DA
https://www.youtube.com/watch?v=_j7U56CSLtI&feature=youtu.be

brian Rupnow
08-11-2015, 10:58 AM
I pulled the head off to check the piston, to make sure it hadn't come loose from the con rod but it was okay. I then seen that the set screws holding the flywheel and key in place had come loose, and that was what was making the nasty "clank" sound at the end of yesterday. I tightened them up and then I monkeyed with the ignition timing and fuel mixture some more. I advanced the spark more than I had tried yesterday, and I believe that is what finally did the trick. Now I have to try and suss out why it is not revving up. The flywheel is heavy, but that won't keep an engine from revving up. A heavy flywheel will only keep an engine from revving up quickly. I have noticed that the intake valve doesn't seem to be moving at all, although it must be moving some for the engine to run at all. I may try cutting half a coil from the inlet valve spring to see if that makes a difference.

bob_s
08-11-2015, 11:14 AM
Brian:

That flywheel looks bigger than the flywheel on my old Norton.

The heavy flywheel may be what is preventing it from going into hit-n-miss mode.

Sum of the torques = moment of inertia times the angular rate of acceleration.

aostling
08-11-2015, 11:21 AM
Well done! It is amazing that the engine runs so well, so soon after completion. The fine-tuning process will be as interesting to follow as the construction phase.

It is such a nifty engine. Scaled up, this design might be good to power a boat.

brian Rupnow
08-11-2015, 11:43 AM
Here we are going in and out of hit and miss mode. As I suspected, the spring on the atmospheric intake valve was too strong, making it difficult for the engine to draw in enough air (and consequently fuel) on the intake stroke. I removed the spring and cut off one full coil, and the engine immediately reached into a much higher rpm range with no other tweaking. The new higher rpm range allows the engine to go in and out of hit and miss mode, but it is running much too fast. I will now put the "medium" governor spring in place and see how much it slows the engine down.
https://www.youtube.com/watch?v=qymo4QU9d0Q

aostling
08-11-2015, 12:03 PM
As I suspected, the spring on the atmospheric intake valve was too strong, making it difficult for the engine to draw in enough air (and consequently fuel) on the intake stroke. I removed the spring and cut off one full coil, and the engine immediately reached into a much higher rpm range with no other tweaking. ...

By shortening the coil spring you made it stiffer, but also reduced the pre-loading (if any). So you have two things to tweak.

brian Rupnow
08-11-2015, 12:40 PM
We're done!!! This is the correct speed for a hit and miss engine to run at. Thank you to all who have followed this thread, and I truly do hope that any new-bees following may have learned something new.----Brian
https://www.youtube.com/watch?v=4Q1dWMnXfj0&feature=youtu.be

woodenbird
08-11-2015, 03:28 PM
Thanks for posting and taking us along this adventure. It has been an interesting trip. A great success!

The Artful Bodger
08-11-2015, 04:07 PM
Thanks Brian for taking us along on your adventures with this wonderful little engine!;)

Rustybolt
08-11-2015, 04:24 PM
Fascinating, as usual, Brian. Thank you.

hitnmiss
08-12-2015, 10:55 AM
Awesome runner! Thanks for sharing Brian

mattthemuppet
08-12-2015, 11:59 AM
I've seen pics of people winding their own springs using a lathe with the appropriate threading gear. Looked pretty nifty and might be a way to get exactly the spring you want for a certain situation.

brian Rupnow
08-12-2015, 04:54 PM
I've seen pics of people winding their own springs using a lathe with the appropriate threading gear. Looked pretty nifty and might be a way to get exactly the spring you want for a certain situation.

I do wind my own tension springs sometimes, using the lathe. Tension springs are easiest, because you don't need to use the lead screw to move the carriage. Compression springs are a bit more involved, generally use a larger, stiffer wire, and you pretty well have to use the lead screw and gears to get uniform spacing between the coils.---Brian

brian Rupnow
08-12-2015, 08:19 PM
Every time I build an engine, I discover something.--The thing about the engine refusing to continue running until I removed a coil from the intake valve spring was a "process of elimination" sort of deal. I knew I had spark. I knew the spark was coming at more or less the right time, or the engine wouldn't have run at all. I knew that I had fuel because I could see it moving in the transparent fuel line. I knew that the valve timing was right, or very close to it. The engine had reasonable compression---I could feel it.The sparkplug was good. This was a very typical problem that has plagued me and others before on these small i.c. engines. They start, they run, but only for 20 seconds or so and then they tail off as if they were running out of fuel. Too strong an intake valve spring (on an atmospheric intake valve) was all that was left. It couldn't suck enough air, and since it is the air movement that creates the vacuum to suck fuel up from the tank through Venturi effect, it was running out of fuel. This was an incredible find!!! Everybody that reads this will now be out in the shop dialing in their atmospheric intake valve springs!!!---Brian

Toolguy
08-12-2015, 09:13 PM
It took a good bit of detective work and some hands on experience to come up with that one! Bravo! That is a great looking and running engine! Thanks for the ride (again).

brian Rupnow
08-14-2015, 08:26 PM
-It's funny how, as you solve the most common issues (poor compression valve timing), then you begin to focus on the OTHER problems. The first set of problems keep the engine from starting. Once you have solved the issue of getting the valves to seal, and your engine will actually start and run, then the second set of issues rears it's head----How to keep your engine running. And once you have your engines so they will start, and keep running, then you start wondering about the issue of "How do I get it to fire ONCE like the full size engines, and then immediately go into miss cycle for 8 or 10 revolutions, then hit again ONCE and repeat the cycle. My flywheel design boils down to "best guess". Right now, I think my flywheel is too heavy. There is simply too much inertia to overcome for that 1" cylinder to fire one time and bring it up to speed. The engine has to fire multiple times to bring it up to a speed where the governors will engage the miss lever. I don't believe it is an issue of the governor spring being too strong or too weak. I think the flywheel simply has too much mass for the bore of the cylinder. I'm not sure I will do anything about it, but I am wondering.---Brian

Lew Hartswick
08-15-2015, 08:12 AM
Brian. Some things just DO NOT Scale. Maybe you've run into one of those here. :-)
...lew...

vpt
08-15-2015, 09:32 AM
Nice running motor Brian! The videos were nice to come back to after our camping trip.

brian Rupnow
08-15-2015, 10:39 AM
Guys--I truly do appreciate your comments and the fact that you stopped by and said Hi. I fully realize that to many veteran machinists, what I am making are just "nonsense toys'. However, I find them exciting, and my machining skills improve with every engine I build.---Brian

The Artful Bodger
08-15-2015, 04:58 PM
Brian, I expect the exhaust port has a lot of bearing on how well a hit 'n miss cycles that and of course the mass of the flywheel.

brian Rupnow
08-16-2015, 08:21 PM
As a point of interest--I have been running the engine intermittently over the last few days searching for that "sweetest of sweet spots" where the carb setting and ignition timing are just about at the perfect spot. I have continued clipping half a coil at a time off the atmospheric intake valve spring, until I am at the point where I can barely feel any compression at all in the valve spring when pressing on the valve stem with my finger. (I have removed a total of 2 1/2 full coils since the engine first ran.) Each time I removed half a coil, the engine ran better.----Now, something I read about in regard to intake valves. I have always reamed the valve guide with an "on size" reamer, and turned the valve stem for a very precise fit in the guide. Of course, the more precise the fit is, the more drag is created on the valve when it opens and closes, and the more important perfect concentricity becomes between the valve guide bore and the actual valve seat. The piece I recently read said to make the valve stem about .001" to .0015" under-size from the bore of the valve guide. This removes any potential "drag" on the valve stem, thus allowing a more lighter and responsive valve spring. It also takes away some of the need for absolute concentricity between the valve guide and the valve seat.--The valve can "float" a little bit concentrically, ensuring a good seal between the valve face and the valve seat. I had inadvertantly turned the intake valve stem a bit smaller than I ususally do, but I thought of the article I had read and decided to use the valve anyways to see what would happen. It appears that the article was correct.

Robw
08-17-2015, 06:38 PM
Hello All, This is my first post on this forum. I don't mean to hijack your thread on this impressive build. I built this same engine during the winter of 01/02 using a King Canada 9x18 lathe with a diy milling attachment and drill press. It was my first model engine and first major machining project. I will attempt to attach a pic.

https://drive.google.com/file/d/0B_YXYmdfgJy1cU1rT1hVZHJORnM/view?usp=sharing

brian Rupnow
08-17-2015, 07:26 PM
The engine is running good. Very good!! I have everything dialed in now to the point where I don't see much room for improvement.---BUT---The engine still has to "hit" 4 times consecutively before it ramps up enough speed to go into "miss" mode. A weaker governor spring won't fix this. With a weaker governor spring, the engine will go into "miss" mode immediately, and not build up enough speed to keep going and "hit" again. A stronger governor spring will make the engine run faster, but not do a lot in terms of hit to miss ratios. I have to get rid of some of the mass in that flywheel. Right now, as it sets, the flywheel weighs 3.2 pounds, and of that 3.2 pounds, 2.72 pounds is in the outer rim. If I set the flywheel up in the lathe and carve away the inner surface of the rim by 33% of the existing thickness on both sides, the rim will then weigh 2.15 pounds.-This equates to a reduction in mass of roughly 21%.---In fact, since I have to remove it from the chuck and turn it around to machine the other side, I can even try it on the engine at the "half way" point where I have only carved away 10.5% of the existing mass. On one hand, I hate to carve up a reasonably pretty flywheel. On the other hand, it didn't cost me anything but my time, and I really would like to have a hit and miss engine that hits once, misses for 5 to 8 cycles, then hits again.
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/FLYWHEEL--OSCILLATING_zpsnbzwsjv0.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/FLYWHEEL--OSCILLATING_zpsnbzwsjv0.jpg.html)
http://i307.photobucket.com/albums/nn294/BrianRupnow/BrianRupnow024/FLYWHEEL--LIGHTENED_zpswlenqjr4.jpg (http://s307.photobucket.com/user/BrianRupnow/media/BrianRupnow024/FLYWHEEL--LIGHTENED_zpswlenqjr4.jpg.html)

dp
08-17-2015, 08:11 PM
Sounds like it needs a proper load like a generator or rotary water pump. Or even a magnetic brake.

brian Rupnow
08-17-2015, 08:22 PM
Dp--under load, they won't run fast enough to go into "miss" mode at all. They "hit" on every compression stroke.As soon as the load is removed the engine will speed up enough to go into "miss" mode.

RichR
08-17-2015, 11:47 PM
Hi Brian
I hope you don't mind if I offer some thoughts (or speculation).

A stronger governor spring will make the engine run faster, but not do a lot in terms of hit to miss ratios. I have to get rid of some of the mass in that flywheel.
The flywheel is basically an energy storage device. If you lighten it, it will take fewer hit cycles to get it up to speed, but return less energy to get
you through miss cycles. The hit to miss ratio will be a function of (power into the flywheel)/(power out of the flywheel). That brings us to this:

Of course, the more precise the fit is, the more drag is created on the valve when it opens and closes, ...
The same holds true for any other close fitting parts in your engine, closer fit, more friction. I bring this up because the frictional losses hit you
twice. Friction reduces power being put into the flywheel during the hit cycles, and reduces it again during miss cycles when it's returning power.
I think the only thing lightening the flywheel will do is increase the frequency at which the motor transitions between hit and miss mode.

The Artful Bodger
08-18-2015, 12:18 AM
Brian, may I mention again the exhaust port. The time the engine will coast is obviously very much effected by the load and a major part of that load is the effort of pumping air back and forth through the exhaust port.

We had a hit and miss which drove sheep shearing equipment and I recall the length of the exhaust was somewhat critical.

John

dp
08-18-2015, 01:17 AM
When a hit and miss engine is coasting the intake valve should not open so there will be no flow of air through the engine. That in fact is how you know your valve spring is working well. It is an atmospheric valve and I suppose a reed valve could be used in its place now that I think about it - they're also atmospheric valves.

It is not or at least should not be a pass-thru air pump but the air does come and go in the cylinder through the open exhaust valve and that is waste energy so the larger that valve head diameter and port the better. These engines have very heavy flywheels compared to other engines of their capacity to help get them through the miss cycles. Brian has settled on a valve cage design for his engines that to my mekanickle mind appear to create a long air path and I spent many hours of my yoot working to shorten those very paths and to improve air flow. Some of that cage is also combustion chamber which creates odd shaped flame fronts, but his engines finally do run fine.

Hit/miss engines I've seen in person have very large exhaust valves and short, fat ports, and much smaller intake valves and made with attention to light weight. I've seen some clever designs that have the exhaust valve in the head and the intake valve in the block. Some have gravity fed fuel drips with governor-controlled needle valves to prevent fuel flow when the engine is coasting.

I wonder too about the issue of applying a load. These engines can handle loads - it's why they existed, so there may be some manufacturability decisions that create operational inefficiencies. I'm not in his shop looking over his shoulder so don't know all the details, but I do enjoy his creativity and enthusiasm for these engines. He's one of my home shop heroes :)

brian Rupnow
08-18-2015, 08:31 AM
Dp--I beg to differ with you. When a hit and miss engine is coasting, the intake valve remains closed, however the exhaust valve is held wide open by the "hit and miss lever" creating a great deal of air flow through the engine. This not only cools the exhaust valve and seat, but cools the cylinder as well. No vacuum is created to draw air in thru the intake valve, that is why it remains closed during the miss cycles. As soon as the engine speed drops below a critical point, the centrifugal governor releases the hit and miss lever, allowing the exhaust valve to close. Immediately, as the piston moves down in the cylinder, vacuum is created, the intake valve is sucked open, admitting a fresh charge of air and fuel so the engine will "hit' again.----I have tried applying a light load by holding my thumb against the rim of the flywheel, ---all this does is make the engine "hit" continuously, with no miss cycles at all. the engine pretty well has to be "free wheeling' with no load to go into "Miss" cycle.---Brian

ammcoman2
08-18-2015, 08:55 AM
Brian,

I recently completed a Nanzy engine (about one cubic inch) but could not get it to run (this is my first IC engine build). With the help of some fellow model club members and my suspicion of the machining of the carb, I used an OS carb from a 0.4 cubic inch engine and connected it to the engine with a manifold, made from Delrin, about 2" long. Excuse the Hillbilly setup! Using Coleman fuel the engine started almost immediately and, after fiddling with the springs on the hit & miss governor, I got it to run quite well. Note that those flywheels are quite "chunky".

http://i56.photobucket.com/albums/g189/ammcoman2/IMG_1710_zpst58tmnuj.jpg (http://s56.photobucket.com/user/ammcoman2/media/IMG_1710_zpst58tmnuj.jpg.html)

This photo shows the engine as originally designed with its long intake manifold.

http://i56.photobucket.com/albums/g189/ammcoman2/IMG_2451_zpsrpgwjw3e.jpg (http://s56.photobucket.com/user/ammcoman2/media/IMG_2451_zpsrpgwjw3e.jpg.html)

Being suspicious of the use of a long pipe on a slow revving engine I then attached the Delrin manifold to the bottom of the pipe still using the OS carb. After starting the engine I couldn't get over how different it sounded - a much louder thump and the engine ran about three times longer on the miss cycle than before. In both cases the carb's throttle was just cracked open so this may have influenced the results.

So, my suspicions were unfounded with respect to long intake manifolds.

Geoff

brian Rupnow
08-18-2015, 09:18 AM
Positive results--With one side of the outer rim machined as per my previous post, (removing approximately 10.5% of the rims weight), the engine now fires 3 times before it goes into "miss" mode. It was firing 4 times before going into miss mode before I machined one side of the flywheel. The flywheel is now back up on the lathe, removing the same amount of material from the other side.

brian Rupnow
08-18-2015, 09:57 AM
With the other side of the flywheel machined away, for a total weight reduction of about 21.5%, I don't at this time see a heck of a lot of difference in the hitting and missing. BOO---HISS!!! This engine has totally different characteristics than my water cooled hit and miss engines. The water cooled engines stay very stable in their set-up demands, requiring that the fuel mixture needs to be slightly leaned out as they warm up, but that is all. This engine gets hot.---Hot enough to burn my fingers with the cylinder. And as the heat gradient changes, so do the set-up parameters. I now have to wait half an hour for it to cool down completely before I mess with it anymore. One thing I know---The little 1/16 cross section x 1/4" i.d. o-ring that I have between the oscillating cylinder and the support bearing is only butyl rubber, and it is probably degrading very rapidly from the exhaust gas passing over it. I may go over today and get a Viton o-ring to replace it. That may help the engine stability.

dp
08-18-2015, 11:47 AM
Dp--I beg to differ with you. When a hit and miss engine is coasting, the intake valve remains closed, however the exhaust valve is held wide open by the "hit and miss lever" creating a great deal of air flow through the engine.

We're kind of saying the same thing. The engine (general case hit/miss engine) is rebreathing its exhaust, so air is not passing through the engine, it is passing in and out of the engine through the same port valve. The difference is muddied given the unique design of this engine and the shared port.

Forgot to mention in the last post that long paths in the intake/exhaust effect scavenging of the exhaust gases, and leave exhaust gases in the vicinity of the intake valve. It shows to go ya that engines run fine with less than million-dollar designs :)

If the engine has only enough HP to overcome its internal friction at the miss point then no additional load is possible. Hard to say what the problem is, but the pool of things it can be are engine efficiency, engine drag, the scale of the engine requires it to run at a possibly undesirable higher RPM (HP being proportional to RPM), the shared port for intake/exhaust sets an upper limit because scavenging isn't possible, and loaded engines create more exhaust than when free-wheeling.

I realize you may not have intended ever to power a device with this engine so this isn't a suggestion to do so, but more to better understand small engines or to sate some curiosity. Lock out the governor and run it with an adjustable load to see what the load/rpm curve looks like. As a minimum it would be nice to be able to drive a cooling fan on this one though the frequency the engine will be run probably argues against further refinements.

This is the first IC hula engine I've seen - all others were steam/compressed air so I'm really impressed that it runs well, given the combustion chamber extends out of the engine to the valve block. You continue to amaze with your unique functional designs.

dp
08-18-2015, 12:07 PM
Brian,

I recently completed a Nanzy engine (about one cubic inch) but could not get it to run (this is my first IC engine build). With the help of some fellow model club members and my suspicion of the machining of the carb, I used an OS carb from a 0.4 cubic inch engine and connected it to the engine with a manifold, made from Delrin, about 2" long. Excuse the Hillbilly setup! Using Coleman fuel the engine started almost immediately and, after fiddling with the springs on the hit & miss governor, I got it to run quite well. Note that those flywheels are quite "chunky".
Being suspicious of the use of a long pipe on a slow revving engine I then attached the Delrin manifold to the bottom of the pipe still using the OS carb. After starting the engine I could get over how different it sounded - a much louder thump and the engine ran about tree times longer on the miss cycle than before. In both cases the carb's throttle was just cracked open so this may have influenced the results.

So, my suspicions were unfounded with respect to long intake manifolds.

Geoff

The paths to the valves are as short as is possible in the Nanzy engine which is quite the opposite of Brian's design, so I would not expect the length of the manifold to be much of an issue, especially at the low RPM range these engines run at. By comparison, look at the intake of a VW Beetle (air-cooled) engine.

That's a beaut!

brian Rupnow
08-21-2015, 01:33 PM
I've spent the last few days studying relationships!! No, not that kind of relationships, ya dirty buggers!! The relationship between engine speed, flywheel weight, and governor spring strengths. The heavier a flywheel is, then the greater a "kick" it needs to bring it up to a speed fast enough for the governors to come into play. That is why my engine had to fire five or six times in a row, each time giving another kick to the flywheel until it was spinning fast enough to trip the governors. At this time there were two ways I could have gone--#1-A lighter governor spring, or #2-a lighter flywheel. I chose to go with the lighter flywheel option, and after much dialing and tuning and disassembly/reassembly, I have it tuned to a point where my engine fires only two and sometimes 3 times before the flywheel is going fast enough for the governors to kick in. Also, I note that with the lighter flywheel, the engine runs at a faster speed than previously. I could shave some more weight off the flywheel, but then we get into the opposite side of the equation--The flywheel has to be heavy enough to carry the engine through 5 or 6 "miss" cycles, and still have enough inertia to compress a charge of fuel for firing after the governors disengage. I don't want to take more off my flywheel and have it too light. It is a lot easier to take metal off than it is to put it back on. Another option comes into play here, that I'm thinking about. The faster the flywheel is running, then the closer it is to the governor "trip point", and the less "kick" it needs to speed up to trip the governors.---However, that defeats the "I want my engine to run slowly" side of things. It's easier for me to change the governor spring than it is to remove and machine more off the flywheel, and at least with changing springs it is easier to "undo the change" than it is if too much weight is taken out of the flywheel.

bob_s
08-21-2015, 02:08 PM
Brian

One other alternative, which may be a little tricky to implement, is to orient the crankshaft vertically.

That would reduce the gravitational component of the bearing friction, aside from what small resultant you would need to compensate for in the thrust bearing required on the bottom of the crankshaft.

-regards
Bob

The Artful Bodger
08-21-2015, 04:18 PM
Brian, this is the way I think of it...

The weight of the flywheel as you say has to be light enough that a single firing stroke will push it up to governor cut out speed and it has to be heavy enough to carry the engine through a few coasting strokes plus the induction and compression strokes when the governor cuts back in. So a few things to play with there, the power of the firing stroke, the weight of the flywheel, the friction during the coasting stage and of course the range of the governor.

Lets look at the friction during the coasting stage, assuming the friction of the engine is as low as practical which I have no doubt of we are left with the dynamic friction of the air flow through the exhaust tract. With this I suspect we are entering a realm where things do not scale very well and I am sure there are text books and even entire libraries devoted to the subject of gas and liquid flow in various circumstances. In this case we need to pump air in and out of the engine with minimum effort and through a tract that is quite small. There is a general principle when dealing with the movement of air that the effects increase in an exponential manner so that doubling the speed of air movement may quadruple the effort required to move it. Therefore I believe reducing the speed of the engine would be a good thing.

Obviously a slow running engine requires a heavy flywheel and a heavy flywheel requires a lot of bang to accelerate the engine to governor cut out. Perhaps increase the bang or reduce the governor range.

These are just my thoughts and are not intended as any sort of criticism of your impressive machine Brian.

brian Rupnow
08-21-2015, 05:04 PM
I am getting very encouraging results by cutting off one coil at a time from the governor spring. The good news is that it is a standard spring from Brafasco, and if I cut it back too far, there are many more of the same where it come from.

brian Rupnow
08-26-2015, 10:50 AM
One final video before I leave this thread behind. I added an anti-backflow valve into the fuel line and shaved away close to 50% of the original flywheel rim thickness to get to the state you see in this final video. ----Brian
https://www.youtube.com/watch?v=oBSHanHaSRU&feature=youtu.be

woodenbird
08-26-2015, 11:57 AM
Great job, Brian. I have enjoyed your build immensely.

vpt
08-27-2015, 08:52 AM
Very nice Brian! Thanks very much for sharing these builds and videos.

That crank and flywheel spin very true and smoothly on this one, looks and sounds to be a very good runner.

brian Rupnow
08-27-2015, 05:06 PM
Thought for the day---Imagine a rock, tied to a 10 foot length of string. Hold one end of the string in your hand, and swing the rock around in a horizontal plane. Once you get it going, you can swing that rock pretty darn slowly, and it will keep the sting tight and maintain it's position. Change up to a five foot length of string. You can still keep the rock swinging, but you are going to have to swing it faster to maintain a tight string and keep the string horizontal. Probably not twice as fast, but definitely faster. Now change up to a 1 foot length of string. It becomes impossible to swing the rock fast enough to keep the string tight and horizontal. Whatever forces are at play here, are probably not linear. The same physics apply to model hit and miss engines. My model is a 1" bore with an approximately 5" diameter flywheel. Let's just for the heck of it, translate that to a 3" bore. That would correspond to a 15" diameter flywheel. I don't have a full size 3" bore, single flywheel hit and miss engine here to measure, but I'm pretty darn certain that the flywheel on such a model would probably be at least 24 to 30" diameter. Not everything is scaleable. I did get the engine to slow down some by retarding the ignition a bit, but not a lot slower.---Sure has been fun though!!!

Lee Cordochorea
08-27-2015, 08:50 PM
Whatever forces are at play here, are probably not linear.

Yes, they're not. :)

Stress on the rope equals mass of the rock times the radius of the swing times the square of the tangential velocity. Tangential velocity, in turn, is proportional to the radius. To get the same tension on the 5' rope as the 10' rope requires the rock to have 1.414 times the tangential velocity. The rpm would be about 2.8x. For the 1' rope, the rpm would be more than 31x the 10' rope to have the same tension. (Multiply the scaling factor times the square root of the scaling factor.)

http://hyperphysics.phy-astr.gsu.edu/hbase/cf.html

http://hyperphysics.phy-astr.gsu.edu/hbase/rotq.html

:)

brian Rupnow
08-30-2015, 03:10 PM
If anyone decides they would like to have a go at building this engine, then send a request to the email address in my web page (not the forum email) and I will send you a free set of my working drawings which are in Imperial (inch) dimensions.---Brian