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brian Rupnow
12-19-2012, 07:46 PM
My brain never stops!!! Not all of my ideas are good ones, but I never run out of mechanical things to think about. Playing about with my model sawmill has got me thinking about simple mechanical clutches. Not something that tightens or loosens a drive belt, and not something that creates "drag" when disengaged. Rather some device that totally and completely disengages the driveshaft from whatever it is driving, and can be engaged softly like the clutch on an automobile, not with a sudden "grab and lurch". It would have to be simple, cheap, small, and a minimum of moving parts. I have many small, single race ball bearings from disassembling various "things" over the years, and they will take a lot of axial as well as radial pressure without failing. I was doodling on a piece of paper, and where the levers are in the sketch, think about a Destaco style clamp. Not the ones with the swinging lever, but the push/pull type. I see the friction material as being oak or maple, glued into a brass or aluminum housing. Not sure if I will build something like this or not, but it is intriguing!!!

http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/CLUTCH002_zps74ddf548.jpg

sasquatch
12-19-2012, 07:59 PM
My friend , you are a deep thinker!! Lol-- Looks logical to me.

Are those coffee stains!!?

Toolguy
12-19-2012, 08:04 PM
The mechanism of an Ettco-Emrich tapping head is just like that. It's called a cone clutch. The way I understand it is that it has a thin layer of leather between the cones. There are 2 cones for forward and reverse. It is very tractable - the more pressure you apply to push the cones together, the more torque it puts out. The tapping head I have is a real pleasure to use. Just an up or down motion of the drill press handle gives you forward and reverse, neutral is in the middle and easily controllable. You can tap an #0-80 hole as easily as a 3/8-16.
Your version should work very nicely. You may want to make the tension spring loaded or screw adjustable.
I have enjoyed following your builds, very interesting and nice work too! Thanks for sharing with the rest of us!
Best Regards - Warren

duckman
12-19-2012, 08:06 PM
Brian first if your brain stops we will all miss you, that said the clutch that you drew is just like the one on my old round tube Cub Cadet,

firbikrhd1
12-19-2012, 08:16 PM
Your drawing is similar to how the brass synchronizer rings work in a manual transmission. AS the shifter is moved the syncronizer ring is pressed against a cone shaped area on the end if a shaft with an integral gear getting it spinning at the same speed as the shaft of the gear being shifted into. The only difference is that the outside of the syncronizer ring has teeth that mesh with splines in the syncronizer assembly.

http://www.youtube.com/embed/L3j6HaAieEU?rel=0

http://automobiles-hariadhikari.blogspot.com/2010/12/synchromesh-gear-system.html

The point of what I have said is that given that syncronizers are small enough to fit inside manual transmissions for cars you might be able to adapt some internal parts of a junk manual transmission to your application instead of starting from scratch.

bob_s
12-19-2012, 08:37 PM
Centripetal clutch yields full disengagement when revs are low.

brian Rupnow
12-19-2012, 08:45 PM
Centripetal clutch yields full disengagement when revs are low.
Yes, you are correct. If I was running my models with a high winding chainsaw or weedeater motor, that would be just the ticket. I used to run go-carts during part of my miss-spent youth, and although we called them centrifugal clutches, I think we're talking about the same thing. However, all of the model machinery I would run with a clutch are quite low rpm devices.

Scottike
12-19-2012, 08:50 PM
That looks very similar to the power feed clutch on my lathe. (Rockwell 10")
but on mine the cone is driven by gear teeth on the od. and engages the
female to drive a gear. The shaft does not rotate and is used only to engage &
disengage the clutch. and of course, I don't think I can get away with using
oak for the cone.

edit: maybe ironwood?

claudev
12-19-2012, 08:52 PM
Cone clutches. Back in the good old days (before hydralics and VS drives), variations of these were very common. They were used in a wide variety of devices from old american lathes to heavy earth moving machinery. Cat, for one used them with a band brake on their exterior surface for winch drive clutches. (Worked on/with them while in uncles employ.) If you are are considering building one for heavy service look in some of the older (60 + years) engineering handbooks for design details.

Another type of smooth clutch/drive mechanism used by some of the "poorboy" loggers and "peckerwood" sawmills here in the deep south and maybe elsewhere might also fill someones needs. These utilize a rear end (from a lawn mower size to a truck size) as a winch or clutch. These utilize the property of a differential whereby the braking of one axle while rotating the differential assembly causes the other axle to rotate. Usually a winch drum is bolted to one axle and the other end is braked/controlled with the original brake mechanism. Often one and sometimes both axles are shortened.

My appologies if the later portion of my reply highjacked your topic. This was not my intention.

flylo
12-19-2012, 09:17 PM
I've had several old Case tractors with hand clutches & loved them. You could be off the tractor while it was in gear & nudge the clutch to move as little as you like without climbing back on. Get a drawing of that & I think you'll like it! JMHO

camdigger
12-19-2012, 10:59 PM
Looks very similar to the clutch on my JD 312 lawn tractor. As I recall, the friction facings look like custom facings of typical material.

Cone clutches are also found on some older small drilling rigs from GEFCO. The cone is activated by an air cylinder.

camdigger
12-19-2012, 11:04 PM
Here is another clutch.

http://i766.photobucket.com/albums/xx301/camdigger/P8151271.jpg

This one uses a bullet shaped cam to spread two spring steel friction shoes against the inside of the driven pulley. It is part of the drive set up for my old line shaft lathe.

becksmachine
12-20-2012, 02:25 AM
It may not meet all your requirements, but one of the cheapest "clutches" that has a soft start is an automotive differential with one working brake.

Not only can this arrangement achieve the entire range of soft-hard starts, prolonged slipping usually has no detrimental effect.

Dave

studentjim
12-20-2012, 09:01 AM
Hi Brian, the clutch that you have sketched up should work faithfully. In my younger years we had a gas powered tugger that had a 3000# line pull with a cone clutch that was activated with about a 3'-0 lever and cam. You could ease the drum into motion so slowly that the cable would just inch along,but the motor would stall before the clutch slipped. The motor was a four cylinder Wisconsin, not sure what the horsepower was, but it was quite large. The clutch was simply made of wood with a material like a brake shoe making contact with a steel cone. Should be very easy to make for a man with your capabilities. Jim

Duffy
12-20-2012, 06:40 PM
Brian, if you intend to try this with local hardwood, see if you can get either dry sugar, (not red,) maple or hop hornbeam, aka "ironwood." Most of our hardwoods are not really suitable for these kinds of compression and friction loads. You might also try persimmon, (look for an old driver.) If you opt for exotics, a lot of them are oily, (ebony, most rosewoods, blackwood, lignum vitea,) and may tend to crack. I have some East African olive which would work well. It is dense, fine grain, not oily, but the postage will kill you!:)

topct
12-20-2012, 08:41 PM
Instead of wood what about a piece of disc brake pad. No dimensions are given for your clutch, but something off a big truck might work if you need something really thick.

brian Rupnow
12-20-2012, 08:58 PM
Good idea Gene, but this is just a little clutch about 2 1/4" in diameter to use on some of the model steam or gas engines that I build. A piece of hardwood (probably oak) will work for this just fine. Duffy--I'll probably just use a piece of oak from the lumberyard near my house. ---Cheap, if not free.---It will never see heavy loading.---Brian

The Artful Bodger
12-21-2012, 02:40 PM
Brian, I spent a few minutes at the library reading up on what we call "bush mills" to learn how they moved the log carriage and found three principles were in common use. Fast and loose pulleys, jockey wheels, slack belts.

In the case of fast and loose pulleys they simply had a flat pulley fixed to a shaft and along side it another pulley that was free to revolve. The belt was guided to one or the other as required, there was a variation where there were was another pulley which the belt could be moved to for reversed direction.

The jockey wheel system had two wheels close together and a rubber or leather tired jockey wheel was brought between them to engage drive.

Slack belts, obvious enough but you did say you didnt want to use that principle.

John

{LATER} Oops! just read your last post.....

Rustybolt
12-21-2012, 04:34 PM
O.r simply buy a used procunier tapping head and use that. I think the mating surfaces are steel and cork. The clutches on a B&S screw machine were phenolic and lasted just about forever.

Fasttrack
12-21-2012, 05:13 PM
Hey Brian -

Check out Machinery's Handbook. There's a whole section on cone clutches and choosing the correct taper, calculating max power transference, etc. I used one for a go-kart several years ago and it worked great. Several old lathe manufacturers use cone clutches, as well.

The Artful Bodger
12-21-2012, 11:56 PM
OK, maybe the easiest clutch of all, but maybe not very elegant. The driven member is an open sided drum and the driver is a wheel of friction material that is a loose fit in the drum. The clutch works by pushing one of these off centre so that the rim of the wheel presses against the inside rim of the drum. Simple but may involve shaft misalignment.

We had farm machinery (sheep shearing machines) that used this principle.

malbenbut
12-22-2012, 05:32 AM
The drawing on post 1 looks nearly identical as the one used on a Kerry lathe, very simple and very effective. I preferred this more than disc clutches which always seems to rattle after being used for a while.
MBB

brian Rupnow
12-22-2012, 11:18 AM
And moving from hand doodles to CAD doodles, we have this. What I have attempted to do here is to ensure that all axial loads are transferred thru the ball bearings instead of any sliding surfaces betwen rotating mechanical parts.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ASSYOFCLUTCH_zps0f67abf1.jpg
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ASSYOFCLUTCH-DRAWING_zpsdaa020a9.jpg
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/SOLIDMODELOFCLUTCH_zps19198b50.jpg

brian Rupnow
12-22-2012, 01:48 PM
Bad on me!!! I forgot to show the drive pin and slot in the shaft in the first drawing I posted.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ASSYOFCLUTCH-DRAWING_zpsdc53ac30.jpg

Jaakko Fagerlund
12-22-2012, 04:25 PM
Is there a reason why you have used regular deep groove ball bearings in a place that screams for thrust bearings?

brian Rupnow
12-22-2012, 04:43 PM
Yes---An excellent reason!!! As I said in my very first post---Because I have them.

Scottike
12-22-2012, 04:56 PM
Is there a particular reason to use the wooden cone rather than
building the whole part in bronze?

Jaakko Fagerlund
12-22-2012, 05:02 PM
Is there a particular reason to use the wooden cone rather than
building the whole part in bronze?
Friction needed? I don't see how you achieve good friction with bronze, as it tends to be used as bearing bushes.

brian Rupnow
12-22-2012, 05:03 PM
Wood has a much higher co-efficient of friction. The wood basically becomes the "friction" disc in this clutch.

brian Rupnow
12-22-2012, 05:08 PM
This is the first part I will make. As you can see, I have added a second groove to it, simply because I have the room. This entire clutch is not going to be a study in superior engineering. Its something to do to keep me from going nuts during the ensuing festive season. I THINK it will work fine and I will post drawings as I go along, because I have to make them anyways for myself. If it works really really great, then you can copy the drawings and save them. If it doesn't work, then at least it will have amused you.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/PULLEYPORTIONOFCLUTCH_zps9d538aad.jpg

brian Rupnow
12-22-2012, 07:48 PM
Here is a little trick that works for me. When I want to go to a non critical flat bottomed hole in a part, which has a smaller thru bore already in it, I stick this 1" dia. 4 flute end mill in the tailstock chuck with my lathe on its lowest speed (about 150 rpm) and crank it in. This seems to put a smaller chip load on the lathe than cranking in a 1" drill bit, and I can go full depth in one shot without having to worry about a tapered bottom like you get from a drill. This side will now be opened out with a boring tool to 1 5/16" diameter, and then I will set my topslide over 25 degrees to make the final taper.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ENDMILLINLATHE001_zpsa85ed1d5.jpg

brian Rupnow
12-22-2012, 08:22 PM
There!!! Enough silliness for one evening. Time to go spend some wife time.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/taperedsideofclutch001_zpsb4168e4e.jpg

brian Rupnow
12-23-2012, 10:37 AM
Thanks for looking and commenting guys. The plan keeps evolving!!! My whole premise behind this clutch is that the bearings do take up all the axial load. Ball bearings like the ones I am using (because I already have them) will take amazing radial loads, but they will take considerable axial loads as well, though not as great. As for holding the lever in to keep the clutch engaged, this latest drawing will show what I have in mind. On the extreme right hand piece the outer diameter of the body will have a 1 1/4" thread on an extended boss and will be threaded thru a plate with a 1 1/4" thread, which is attached to the baseplate. A handle on it will engage or disengage the clutch by swinging in an arc to advance the entire end (holding the bearing) on the threads. Since the threads on a 1 1/4" nut are quite coarse, a 45 degree swing of the handle should advance all the pieces sufficiently to engage the clutch, and it should hold its position there untill the handle is revolved 1/4 turn in the opposite direction. This is very hard to get your head around, but the drawing I have posted should make it clearer.---Brian

http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ASSYOFCLUTCH_zps8d191480.jpg

1-800miner
12-23-2012, 11:28 AM
Are you sure you want only one bearing in the mounting block/shaft support?


Never mind,I see it now.

Sometimes I suffer from ADOS......attention deficit...oh shiny!

Jaakko Fagerlund
12-23-2012, 11:38 AM
Nice idea that engaging with a thread!

Barrington
12-23-2012, 12:06 PM
An observation on clutches in general - with any type of friction clutch the slip is controlled by the force with which the friction surfaces are pressed together

If you attempt to control it by 'position' only (i.e. using the motion of the thread as above) the control range is likely to be very small. (i.e. the coupling goes from zero to locked over a very short throw of the actuating lever.)

Now this may well be the design goal in this case, but if not, fitting an appropriate spring between the actuator and the friction surface will allow the clutch pressure to be varied smoothly over wider arc of the lever.

(Any flexing in the bracket or compression of the friction material will also increase the operating range.)

Cheers

.

brian Rupnow
12-23-2012, 12:13 PM
Barrington--I'm playing "Find out as I go along." Since my drive belts are rubber o-rings, they will take a lot of the "grab and lurch" out of my system, As far as the actual travel from 0 engagement to full engagement, I'm hoping to achieve it in about a 45 degree swing of the lever. A 7 TPI thread will have 0.143" of linear movement per full turn, so divided by four that gives about .036" im a 45 degree arc.

Toolguy
12-23-2012, 01:09 PM
Hi Brian-
That looks like a good design! I wonder if I'm understanding it correctly though. It seems to me like the slot in the shaft for the drive pin should be on the right side of the pin instead of the left. I don't want to be critical, just trying to understand. I do like the threaded on and off lever idea!

becksmachine
12-23-2012, 01:25 PM
Brian, your CAD renditions are amazing!! ;)

Not only that but they are clear and relatively un-ambiguous.

One observation, most of these type clutches have some type of over-center mechanism to maintain pressure on the friction faces. With the otherwise elegant threaded arrangement you have now, I fear that the smallest vibration would allow the "screw to unscrew" and allow slippage.

The fix could be as simple (inelegant??) as a bungee cord on the lever to hold it in the engaged position.

Dave

brian Rupnow
12-23-2012, 01:31 PM
And here's how the other side turned out. I am always amazed by the infinitesmaly (is that a word?) small difference between a press fit and a Loctite fit!!! This was supposed to be a "light press fit" . It turned out by about one zillionth to be a Loctite fit. No fear though. I had reamed the bore on the fabricated part and it was right on. So---I slipped a piece of 3/8" cold rolled shaft thru the fab'd part, slipped the bearing over that, slathered on a bit of 638 Loctite, and together it went. Concentricity gaurenteed.

http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/BEARINGINPULLEY001_zps6f2426fe.jpg

brian Rupnow
12-23-2012, 01:34 PM
Hi Brian-
That looks like a good design! I wonder if I'm understanding it correctly though. It seems to me like the slot in the shaft for the drive pin should be on the right side of the pin instead of the left. I don't want to be critical, just trying to understand. I do like the threaded on and off lever idea!
Yah, you're right. We'll split the difference. I'll put the slot centered on the pin. That will allow some movement in both directions.---Brian

Scottike
12-23-2012, 01:41 PM
Very nice design Brian, I like it!
the only reason I mentioned bronze vs wood is that is what the cone clutch
on my lathe uses.
Do you have any concerns about the threaded engagement tightening itself
while the clutch is running? (or loosening if it's rotating the other direction)
I know it doesn't look like it should, but best laid plans and all that.

brian Rupnow
12-23-2012, 02:05 PM
Not overly concerned. My drives are all fractional horsepower. I would have opted for a "push-pull" mechanism similar to some Destaco clamps, which are an "over center" device, but then the clutch gets too long.

brian Rupnow
12-23-2012, 02:20 PM
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/OAKHARDWOOD_zps49cad474.jpg

brian Rupnow
12-23-2012, 02:35 PM
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/CLUTCHOUTERBODY_zps573d1e11.jpg

co_farmer
12-23-2012, 07:27 PM
My Dad had a portable sawmill in the late 1940s, early 1950s. He used a model A coupe with no body to cut full length trees into sawmill length using a chain saw bar driven by one wheel. Braking the opposite wheel would drive it. That opposite wheel also drove a winch drum that would pull the tree in for the next cut when the chainsaw side brake was applied. The normal inactive operation was to have the brake on the winch side locked on and the chainsaw bar raised, but the chain still running. That was the only good use I ever saw for Ford mechanical brakes!

If a long wait was going on, they just shut off the engine.

A portable sawmill was one that could be disassembled and loaded onto trucks and moved to a new site.

Paul

brian Rupnow
12-23-2012, 07:51 PM
I know a very funny story about a model A powered buzz saw.

sasquatch
12-23-2012, 08:05 PM
AND,,,, I,m just waiting to hear it ,, Please?

Haven't heard a Rupnow story now for some time!!:(

brian Rupnow
12-23-2012, 09:37 PM
Okay Saquatch---You asked for it. I've posted this before, but its a very funny true story, and well worth telling again. I think of it every time I see "Model A" and "saw" in the same sentence.
I grew up in the kinder, gentler, far more poverty stricken world of the 1950's. I have a firm belief that it wasn't necessity that was the mother of invention---poverty was. The lack of money created a world of tinkerers and inventors, simply because there was no money to buy the proper tool or machine. An older friend of mine, named Leonard had built a portable buzz saw for cutting firewood. This was basically a 48" diameter circular saw mounted on the chassis of a model A Ford, circa 1930 or 1931. The lengths of wood were lifted onto a tilting carriage, and the carriage was tilted into the saw to cut up lengths of firewood. The saw was driven by a flat belt and pulley arrangement that came from the rear of the old Fords transmission. Now, Leonard had a problem----The old 4 cylinder Ford engine had babbit bearings, so it did not take kindly to prolonged high speed revving. However, if someone didn't open the throttle and give it some gas when the log engaged the saw, the engine would stall. Leonard was a veteran tinkerer, and somehow come into the posession of a set of flyball governors off an old steam train. He mounted them with a belt drive from the Ford engine, and hooked them up to the carburetor with a system of levers and pulleys. The theory was quite simple---under no load conditions the old Ford would set there idling, but as soon as the log engaged the buzz saw, the rpm's would drop off, and the flyball governors would open the throttle automatically. this was a perfectly good working theory!!! The problem was that Leonard somehow got one of his lever arrangements bass ackwards. When the last bolt was tightened, and the last brace welded in place, Leonard went to test his creation. He started the Ford---that part worked perfect. As soon as it started however, the flyballs began to fly outward from centrifugal force, and the farther out they flew, the more the lever mechanism opened the throttle. The engine went from zero to a zillion rpm's in the blink of an eye. Leonard leaped from the drivers seat and raced around the car to pull off the coil wire and shut down the engine---and at the same time the flyball governor self destructed (it too was by then doing a zillion rpm's). One of the steel balls flew and hit poor Leonard directly in the kneecap and broke it into a dozen peices--then the old Ford engine self destucted in a scream of tortured babbit bearings and shattered castings!! Leonard eventually recovered, though he walked with a limp ever afterwards. We all survived the 1950's, but it certainly was a time that gave rise to a lot of interesting stories.---Brian.

djc
12-24-2012, 04:59 AM
...As far as the actual travel from 0 engagement to full engagement, I'm hoping to achieve it in about a 45 degree swing of the lever. A 7 TPI thread will have 0.143" of linear movement per full turn, so divided by four that gives about .036" in a 45 degree arc.

I don't know if it is a showstopper but there are eight lots of 45 degrees in a full turn, not four. There are, of course, four lots of 90 degrees.

Black Forest
12-24-2012, 05:08 AM
I don't know if it is a showstopper but there are eight lots of 45 degrees in a full turn, not four. There are, of course, four lots of 90 degrees.

Hey go easy on Brian. Remember he is a Engineer and we all know they are not known for their math skills, common sense and buildabilty (see Brian I can make up words also) when designing. Or at least the ones that worked for me in a former life!

brian Rupnow
12-24-2012, 10:05 AM
Ahh---Would you believe I had just been out mushing my team of huskies, and was a bit snowblind when I did that 45 degree calculation?????--If not, I'll think of something else.---Brian

brian Rupnow
12-24-2012, 11:39 AM
There----Thats the outer clutch housing finished. I did manage to get a much better fit on the bearing this time. I lined both pieces up on an old 3/8" bolt to take this picture, as I couldn't find a piece of 3/8" cold rolled. Maybe I will have time to make the oak friction cone and epoxy it in place later today. Gotta go now and do Christmas things.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/outerclutchhousing001_zps1d129bb4.jpg

ironmonger
12-24-2012, 11:54 AM
I realize this is a little late to comment on design... :), but the clutch looks to be similar to those found on new style Little Giant power hammers. They were maple wood blocks simply bolted onto the inner clutch drive and engaged a cast iron conical surface. One of the design 'elements' that caused excitement was the end play in the system. If the clutch mechanism could not pull the blocks out of engagement because the shaft drifted back and forth, the clutch would not disengage. That was exiting.


Here Sid talks about the clutch a little, but if you look closely you can see the 180 degree opposite clutch block mounting instead of a drum with near 360 lining. The clutch blocks responded well to a light oiling.
http://www.youtube.com/watch?v=vuYddtwcp0Q

The early ones, as shown here:
http://www.youtube.com/watch?v=KVAJFublLY4
used belting or brake lining.


This doesn't really show the new style clutch but...:
http://www.youtube.com/watch?v=E0ICdvaU94o



(http://www.youtube.com/watch?v=E0ICdvaU94o)

brian Rupnow
12-24-2012, 01:41 PM
The oak, turned to correct o.d. and epoxied into the outer metal housing.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/oak-1002_zps890be9d5.jpg

brian Rupnow
12-24-2012, 04:48 PM
The oak machines very cleanly at 1620 rpm, with HSS turning tools and/or carbide boring tools.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/oakmachined002_zpsc1471bec.jpg

brian Rupnow
12-24-2012, 05:40 PM
I "blued" the inside of the metal cone with some Dykem layout dye, and after it had completely dried I set up both parts on a 3/8" alignment shaft and spun them in opposite directions by hand. The initial results appear very good. I had to swing my topslide over to the opposite side to turn the oak, and I set it to 25 degrees by the protractor built into the topslide. The protractor is marked in 1 degree increments and is only slightly better than a guess. I know that if things weren't perfectly concentric, they would be after the first 5 minutes of actual use. From the pattern I see where the Dykem wore off the aluminum and onto the oak, I think I got it pretty close.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/BLUEDCONE001_zpsebf5e7fa.jpg

Lew Hartswick
12-24-2012, 10:20 PM
Brian, I liked that note on the thickness of the Oak part. :-)
...lew...

brian Rupnow
12-26-2012, 09:54 AM
This morning I made up a drawing of the main support bearing. More to determine whether I have a piece of material big enough or not.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/SUPPORTBEARINGSTAND_zps29473ccf.jpg

brian Rupnow
12-27-2012, 03:08 PM
Thru good luck, 4$, and some creative begging I was able to scoop a 1 1/4"-7 hex nut and about 3" of threaded rod this morning. I keep changing the right hand end of the clutch, and refining it so that none of the rotational moments feed back thru to the thread which forces the clutch faces together. The wood in the background is boards sawn from my model sawmill.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/threadedrodandnut001_zps7ab3e906.jpg

brian Rupnow
12-27-2012, 04:29 PM
Sometimes I think that the quality of my life would improve if I could cut single point threads on my lathe!!! However I can't. First it was learners inability, Then somehting went crunch in the leadscrew drive. So----I live with work arounds.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/CLUTCHPRESSUREMEMBER_zpsfbad0e61.jpg

brian Rupnow
12-27-2012, 09:20 PM
I just finished the part which "activates" the clutch cones, to move them together or apart. I was going to weld the threaded portion to the turned portion of shaft, but found out that the piece of what I thought was 1 1/2 diameter steel was actually cast iron. Thats okay though. Since the threaded portion sets up against a shoulder when the clutch is being engaged, Loctite 638 will suffice to keep the two pieces together. The cross hole for an anti rotation pin has not been drilled yet.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/THREADEDPARTOFCLUTCH003_zpsa4a6be2c.jpg

brian Rupnow
12-27-2012, 09:30 PM
The design of the right hand end of this clutch mechanism keeps evolving, as I think of potential problem areas and ways to overcome them. This is the latest vesion, in which the part with the external thread on it has an anti rotation pin riding in a slot, so that none of the rotational moments up at the "cone" end can be transferred to the part with the external thread, causing it to tighten or loosen by itself.

http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ASSYOFCLUTCH_zps5fed5be0.jpg
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ASSYOFCLUTCH-solidmodel_zps74e6cc9b.jpg

Scottike
12-27-2012, 10:12 PM
Is that a circular gib to the right of the threaded
engagement screw, Brian? Half moon?
I hate it when things go "Crunch!"

edit: I meant my other left! (right!)

brian Rupnow
12-28-2012, 09:55 AM
Scott--if its the two triangular shapes you are looking at, no its not a gib. It represents the weld bead holding the threaded outer portion and unthreaded inner portion together. As it turns out, I couldn't weld it anyways, as the inner peice that I thought was steel was cast iron, so I loctited them together instead. I don't have threading capabilities on my lathe so thats the reason its made in two pieces and then joined instead of all carved from one piece.

brian Rupnow
12-28-2012, 10:56 AM
This is where I'm going next---
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/THREADEDRING_zps6bc2c001.jpg

brian Rupnow
12-28-2012, 12:57 PM
Well, is it starting to look interesting yet? Thats all the internal parts finished. The #10-24 threaded rod screwed into one of the tapped holes in the ring was just there to give me a temporary handle to see how smoothly things turned. While I had the rotary table set up, I also added the 3/16" hole for the anti rotation cross pin in the part which I made earlier today.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/partialassembly001_zps10dc3107.jpg

brian Rupnow
12-29-2012, 03:15 PM
In my great surge of creativity and rush to complete the mechanical clutch, I did the unthinkable!!! I designed a part which, although it looks just great, simply can't be built with the tooling I have. That cut out in the center with a 0.906" radius is impossible for me to machine. The design engineer thought it made perfect sense. The machinist looked at it and after studying the drawing for a few minutes said "How in H%$# am I supposed to machine that???" So---The design engineer sat down, screatched his head for a while, and said "I Know!!! We'll make it in two pieces with the split line right on the center of that .375 width and bolt the two peices together with a couple of alignment dowels to keep everything concentric. And thats what he did!!! (The alignment dowels are not shown in the solid model.)
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ENDPLATEWITH125INTERNALTHEAD_zps98febd54.jpg
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ASSYOFENDBLOCKS_zpsaa805bcd.jpg

Toolguy
12-29-2012, 03:22 PM
Hopefully the Machinist will not be too hard on the Engineer!:rolleyes:

Scottike
12-29-2012, 03:23 PM
Don't you just love it when the engineer and machinist can work well together,
instead of pointing fingers at each other for whose to blame!

Black Forest
12-29-2012, 05:58 PM
That is why every engineer that worked for me had to work in the shop before I would let them design anything. I wanted them to know every process first hand and to design machines that could be built. And be built with what we had in the shop. Some got their feathers ruffled having to do the work in the shop and I can tell you the weldors really put the screws to the engineers. They were harder on them than the machinists. But weldors are like that aren't they!!! I always let the engineers know that they were there to support the machinists and weldors not the other way around. If they could stand the trial by fire they ended up good employees and had the respect of the others.

When I sold the company to my management team I told them that they had better keep in mind that they work FOR the shop and once I was gone if they got on their high horse they would lose a lot of long time employees that made the company successful. As far as I know not many have left since I sold out so they must have listened.

Jaakko Fagerlund
12-30-2012, 08:30 AM
In my great surge of creativity and rush to complete the mechanical clutch, I did the unthinkable!!! I designed a part which, although it looks just great, simply can't be built with the tooling I have. That cut out in the center with a 0.906" radius is impossible for me to machine. The design engineer thought it made perfect sense. The machinist looked at it and after studying the drawing for a few minutes said "How in H%$# am I supposed to machine that???" So---The design engineer sat down, screatched his head for a while, and said "I Know!!! We'll make it in two pieces with the split line right on the center of that .375 width and bolt the two peices together with a couple of alignment dowels to keep everything concentric. And thats what he did!!! (The alignment dowels are not shown in the solid model.)
Nah, that just would have required some lathe work to make it :) Though would have been interesting, highly unbalanced item, cut that will almost put it in half and interrupted cut for some time.

So give your engineer some slack, it wasn't near impossible yet ;)

brian Rupnow
12-30-2012, 05:46 PM
Making the endblock in two pieces is the only way I can make this part.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ENDBLOCK-1_zpsbfdbd80b.jpg
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ENDBLOCK-2_zps9cdde4d9.jpg

brian Rupnow
12-30-2012, 06:08 PM
Wanting to do this in as few set-ups as possible, I clamped a 2" x 1" x 12" piece of aluminum bar to the mill table with a 1/4" spacer bar under each end. This was to raise the piece being machined up of the mill table so I could drill thru it without damaging the mill table. I aligned it very carefully with the right to left axis of the mill and then cut away two areas to the finished thicknesses of .938" and .813", both about 3/8" longer than the part it would make. Then all bores except one and all bolt holes and tapped holes were done without having to move the part. I also milled away the 1" x 3/16" x 2" relief on the mating faces while in this set-up. The faces which were machined will face each other when the two parts are seperated and bolted together. Of course that means that there is one bore which will be on the far side as well as 4 bolt counterbores. I will flip the part over, pick up position off of the .75" reamed hole, and then put in the final 1.5" dia. counterbore and the c'bores for the bolt heads. I hope I have this sequence figured out correctly, and it seems to be going okay so far. I will use the round piece that registers in the .75 bore and the 1.5" bore as an alignment tool when bolting and doweling the two pieces together.

http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/firststep-endblockmachining001_zpsa9d3a7ec.jpg

http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/firststep-endblockmachining002_zpsb99c4e38.jpg

brian Rupnow
01-01-2013, 03:04 PM
Happy New Year everybody!!! Things keep moving along, and as the work progresses the design keeps evolving. These drawings are current and will not change, because the parts are made and assembled. I will be posting a video a bit later today of this actuating mechanism working.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ENDBLOCK-2_zps287759a3.jpg
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/CLUTCHPRESSUREMEMBER_zps26175486.jpg
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/BUSHING_zps318a39de.jpg
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/ENDBLOCK-1_zps28f14b41.jpg

brian Rupnow
01-01-2013, 06:56 PM
Here is a rather shabby quality video of the clutch actuator working. I am fighting with my camera today, and this is the best of 3 videos I made of the same thing. Its not great, but it does show the action very well.----Brian
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/th_CLUTCHACTUATORMOVIE_zps6cee0f8a.jpg (http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/CLUTCHACTUATORMOVIE_zps6cee0f8a.mp4)

Tony Ennis
01-01-2013, 11:35 PM
Cool beans, I've been enjoying the build.

alchymist
01-02-2013, 01:30 PM
Nice plan, great execution! For those of us who don't have the inspiration -

http://www.amazon.com/Ingenious-Mechanisms-Designers-Inventors-Set/dp/0831110848

Can be had cheaper used. I have the 1st three volumes, looking for the 4th.

brian Rupnow
01-02-2013, 02:34 PM
This is the last part I have to make, other than the shaft and the final pulley (which I will change to a double groove). I finished the part this morning that looks like a large pillow block bearing, all except for rounding the top, which I do on my big stationary belt sander out in the main garage. However, wife and I are both sick with the cold. I'm recovering, she's in bed----And her bedroom is right above the main garage. I won't be firing up the big belt sander until wife is up and about.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/BASETIEPLATE_zps158009dd.jpg

sasquatch
01-02-2013, 05:11 PM
Good plan Brian keeping the missus happy goes a LONG way on projects!! Lol

(Lots got this crap of a flu or whatever is going around.)

brian Rupnow
01-02-2013, 07:05 PM
Almost finished!!! I have to make a pulley for the outboard end and put a slot in the shaft, thats all. What about the gap?--Oh, that gap. Well---I left the oak about .080" longer than what the drawing called for, to give me some "extra" friction surface to wear away, then went and built that bottom plate to the blueprint. Thats okay. I sort of figures there would be some fine tuning when I got to this stage of things.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/CLUTCHALMOSTDONE-2001_zps0cfbcc1b.jpg

sasquatch
01-02-2013, 07:24 PM
Looks great and pretty fancy with the brass knob.

Make sure you stamp your'e name and date under it for people of the future!!

brian Rupnow
01-03-2013, 09:36 PM
How do you put a 3/32" slot thru a 3/8" diameter steel shaft?---Answer: The same way porcupines make love.---VERY carefully!!! I drilled thru the shaft at what would become the ends of the slot, then walked a 3/32 carbide endmill back and forth taking about .010 doc each pass. Held my breath the whole time, but it turned out okay. I thought I was ready for final assembly, then realized that I still hadn't made the 3/8" diameter shaft collar that prevents the pulley part of the clutch from following the friction disc along the shaft when the clutch is disengaged. Then after taking another look at the assembly drawing, I realized that if I put a set screw thru the outer diameter of the collar the normal way, I wouldn't be able to get at it to tighten it up unless I drilled an access hole thru the face of the pulley. I will look at it more closely tomorrow. I may have to put the set screw thru from the side at an angle. At any rate, here is a picture of all the parts except the shaft collar and the outer pulley.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/SLOTINSHAFT-2001_zpsc2fdec2b.jpg

brian Rupnow
01-04-2013, 06:23 PM
Just enough room--barely, barely---with a cut down allen wrench, to reach in and tighten the screws in the shaft collar.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/JUSTENOUGHROOM002_zpse5536e8f.jpg

brian Rupnow
01-04-2013, 08:00 PM
The clutch works!!! At least it works as near as I can tell by turning the shaft with a pair of vice grips while engaging and disengaging the handle and holding the cone-pulley with my OTHER hand. Yeah, I know. Thats 3 hands!!! Can't really tell a lot until I get this pulley made and get things hooked up with my o-ring drive belts.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/DRIVENPULLEY_zps3d616983.jpg

brian Rupnow
01-04-2013, 09:20 PM
Teaser shot!!! I haven't tapped the set screw threads in the pulley yet, but I just had to see what it looked like. The outer pulley is driven, the inner pulley is the clutched pulley. Although, I suppose it could just as well be the other way round.
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/TEASER002_zpsf0be1055.jpg

brian Rupnow
01-05-2013, 03:56 PM
Here we have the promised video of the clutch in operation. Bear in mind that the clutch is brand new, and consequently a bit stiff untill it gets ran for a while and loosens up. The sawmill takes very little power to drive it, but the stiffness in the clutch is the reason that the electric drill was working as hard as it appears in the video. Once this clutch mechanism is fully "run in", it will take very little power away from the engine it is used with. My trusty Canon digital camera has crapped out on me, so I just went and bought a Sony DSC-H90 to make this video.---Brian
http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/th_CLUTCHDRIVINGSAWMILL_zps1d315822.jpg (http://i307.photobucket.com/albums/nn294/BrianRupnow/CONTINUATION%20OF%20MAIN%20ALBUM1/CLUTCHDRIVINGSAWMILL_zps1d315822.mp4)

Tony Ennis
01-05-2013, 06:19 PM
Very nice. Thanks for taking the time to post all those photos.

sasquatch
01-05-2013, 09:07 PM
A great piece of Inventive workmanship Brian!!

(hope you all are on the mend!!)

jdunmyer
06-09-2013, 06:02 PM
Resurrecting the thread:

My buddy & I built 4 of these clutches, but we did make a couple of minor changes:

Both our pulleys are conventional flat belt style, crowned in the middle. We drilled a hole in the pulley for the Allen wrench rather than cut it down (see post #84). I don't know what my buddy will do, but I've lashed my first one to the sawmill, using the center as the Drive pulley, with the outboard one being the Driven. My reasoning is that the thing will probably run most of the day, mostly disengaged. That pulley is running on a ball bearing, whereas the shaft is running in a brass pilot bushing on the inboard end. I wanted to minimize the wear on that, besides it mounted up to the sawmill better this way. Also had to machine a radiused clearance under the pulley; the Clipper lacing rubbed very slightly.

First pic is of the front:
http://www.oldengine.org/members/jdunmyer/4show/clutchfront.jpg

Second pic is from the rear:
http://www.oldengine.org/members/jdunmyer/4show/clutchrear.jpg

The belt between the clutch & sawmill is a hunk of an old serpentine belt, spliced with Clipper lacing. It's only 3/4" wide, as that's what my buddy made the pulley, per the print. The belt between the engine and clutch is 1/8" leather, also connected with Clipper lacing. It's just shy of an inch wide.

The mount is just a piece of 1/4" X 3.5" X 7" aluminum with 2 tapped holes to mount the clutch and 2, 1/4" slots to mount it to the sawmill and allow belt adjustment. I will probably scallop it out below the clutch, just to make it look a bit more finished.

Of the 4 clutches, 2 have a fair amount of drag when they're engaged. The Drive pulley has nearly zero drag, as it's just running on the ball bearing. The other 2 clutches run pretty free, even when engaged.

Once again, Thank You, Brian for sharing your work. We had fun building these things, and will get many hours of fun running them.

AJA
06-11-2013, 04:06 PM
I remember using a 5 hp vertical shaft rototiller which used this (http://www.stollerlawnandgarden.net/pages/CustomCatalog/Product/2198083) for the clutch lining.

The lining was free to float between the output shaft of the engine and the input of the gearbox of the tiller.

Many times I would stall the engine when hitting a tree root. The clutch would never slip.

I think this would work in some of your applications.

AJ

jdunmyer
06-11-2013, 06:44 PM
AJ,
Actually, the wood that Brian calls for works fine. First of all, there will be probably 1/2 a ft.-lb. of torque at most that the clutch sees, and secondly, the slippage upon engagement will be minimal.

I'll know more after this coming w/e, when I'm operating my sawmill at Coolspring, PA. Each cant sawed calls for about 8 clutch operations. I'll know if the lining is wearing or if there's any slippage, but tests so far make it look very promising.

Abner
06-12-2013, 09:57 AM
Holy crap! From doodles to finished - nice! I feel like the last kid to the party and that is a good thing as your sawmill looks to be a vertical reciprocating type. My comments would be for the circular/ movable carriage type mill which I own an old one.

For those fertile minded mechanism types there is a sawmill transmission that I have only seen one of. A large round flat plate under power. Across the face of this plate was shaft with a small movable rubber coated wheel. This shaft/wheel controlled the carriage movement forwards and backwards depending on which side of the plate the small rubber wheel on. It gave not only forward and reverse but variable speed depending on the distance from the center of the drive plate. Not sure on the wear but it was very unique.

I had the old friction wheel/ belt type "transmission" in the beginning and latter upgraded to a (2) slack belt system. Not applicable here at all

Nice work Brian. Your doodles to CAD always impress me.
Abner

alchymist
06-12-2013, 10:08 AM
Holy crap! From doodles to finished - nice! I feel like the last kid to the party and that is a good thing as your sawmill looks to be a vertical reciprocating type. My comments would be for the circular/ movable carriage type mill which I own an old one.

For those fertile minded mechanism types there is a sawmill transmission that I have only seen one of. A large round flat plate under power. Across the face of this plate was shaft with a small movable rubber coated wheel. This shaft/wheel controlled the carriage movement forwards and backwards depending on which side of the plate the small rubber wheel on. It gave not only forward and reverse but variable speed depending on the distance from the center of the drive plate. Not sure on the wear but it was very unique.

I had the old friction wheel/ belt type "transmission" in the beginning and latter upgraded to a (2) slack belt system. Not applicable here at all

Nice work Brian. Your doodles to CAD always impress me.
Abner
Typical in snow blower variable speed drives.

brian Rupnow
06-13-2013, 07:10 PM
Jim Dunmyer---I love it!!! I'm so happy the clutch works well for you, and I appreciate your showing the clutch you made and your working sawmill rig. I just got home today, from USA, (see "Chased back to Canada".)---Brian