Author Topic: Line-Shaft Clutch (Read 15511 times)

Brian Rupnow · « **on:** October 03, 2016, 04:58:06 PM »

After doing a bit of research on line shaft style clutches, with a manually operated swing lever to actuate them, I've decided to build one, "Just to see if I can!!" (This train of thought was brought about by John who is building the 19th century machine shop diorama on Model Engine Maker). A bit of research yesterday showed me that the smallest I can possibly make this clutch is 1.75" outer diameter, to work on a 1/4" diameter shaft. There are a few parts to this "expanding shoe" style of clutch that become too small for me to make if I try to make the clutch smaller in diameter. I have made use of a keyslot cutter in a very unorthodox manner to get started on this, and since I'm doing this in "real time" I will keep you posted of my progress.---Brian

Brian Rupnow · « **Reply #1 on:** October 03, 2016, 06:34:13 PM »

This is the center hub of the clutch. It is fixed to the line-shaft. The expanding shoes which transmit torque to the outer hub slide in the miniature T slot which was cut thru with the keyway cutter.

Brian Rupnow · « **Reply #2 on:** October 03, 2016, 10:01:35 PM »

Some very close (fiddly) work here. First picture shows cutting a 1/16" slot into one side of the sliding pressure shoe. Second picture shows the sliding pressure shoe profiled for a sliding fit into the brass part. That slitting saw blade is 1/16" wide!! Next step will be to separate the sliding shoe into two pieces, one to bit on each side of the center of the brass.

b.lindsey · « **Reply #3 on:** October 03, 2016, 10:43:11 PM »

That looks great Brian and quite workable. Hard to imaging scaling it down enough for John to use on his diorama, though he is crafty with the small parts.😊

Bill

Brian Rupnow · « **Reply #4 on:** October 03, 2016, 11:41:32 PM »

Bill this clutch will probably end up being 1.7" diameter. that is roughly twice the size he wants to end up with. I can't imagine machining something that small myself. However, he is doing some amazing small stuff.----Brian

crueby · « **Reply #5 on:** October 03, 2016, 11:52:13 PM »

Quote from: Brian Rupnow on October 03, 2016, 11:41:32 PM

Bill this clutch will probably end up being 1.7" diameter. that is roughly twice the size he wants to end up with. I can't imagine machining something that small myself. However, he is doing some amazing small stuff.----Brian

Make a good contest, who can make it smallest. My money is on George.

Brian Rupnow · « **Reply #6 on:** October 04, 2016, 12:10:46 AM »

This is just about at my limit for "small stuff". The "sliding pressure shoes" are finished. the side where you can see the heads of the socket head capscrews faces inward towards the clutch drum. The side where you see the slots and the shanks of the #40 shcs faces out. The dark blue "actuator arms" (as per the solid model) fit thru the slots in the brass part and bolt to the "sliding pressure shoes". There is a full 8 hours in what you see here.

90LX_Notch · « **Reply #7 on:** October 04, 2016, 12:25:29 AM »

I think one half that size would be doable. In racing, the mantra is that you can never go fast enough. In this hobby it should be, you can never go small enough. I think I will add that to my tag line. Thanks Brian and Chris.

-Bob

crueby · « **Reply #8 on:** October 04, 2016, 12:36:27 AM »

This has been very interesting so far - never knew how they controlled the lines shafts other than sliding belts on and off, plus a neat build to watch!

Brian Rupnow · « **Reply #9 on:** October 04, 2016, 01:19:19 AM »

This is a "real" line-shaft clutch set-up, and it is what serves as the basis for my design. One thing that the "real" one has and my model doesn't (because of scale/space restrictions) is individual adjustments for the tapered surfaces on the arms that the sliding cone interacts with. That would serve to adjust the sliding pressure pads on each side to contact the inside of the drum equally. At the scale I am working, there simply isn't room for threaded adjusters, so I will have to resort to grinding the angled contact surfaces on the dark blue "arms" to get equal travel/pressure on both pressure pads.

Brian Rupnow · « **Reply #10 on:** October 04, 2016, 01:19:43 AM »

I don't THINK that there were any springs in there to retract the shoes and disengage the clutch, but I really don't know. That picture is one I downloaded off the internet. I have never seen one of these clutches in "real life". If anyone has info to the contrary, please let me know.---Brian

Brian Rupnow · « **Reply #11 on:** October 04, 2016, 01:38:54 AM »

I'm going to make a small change to the pulley drum. Since most of the machinery I drive use 1/8" diameter rubber O-rings as drive belts, and we will want to actually "field test" this clutch, I have put a groove in the green drum to keep the o-ring in place.

J.L. · « **Reply #12 on:** October 04, 2016, 01:16:31 PM »

Fascinating Brian! Thanks for having a go at design and execution of the part. I appreciate your insight into this little project and will post my progress as I attempt stop make a rather primitive version of your larger model. We think very much alike on the design. I plan to make both shoes, their studs that project out the front of the plate and the internal collar all out of one round piece of metal.

I've always enjoyed making prototypes, and I can see why you wanted to try this as well.

I love your computer generated design.

John

Brian Rupnow · « **Reply #13 on:** October 04, 2016, 04:34:46 PM »

This morning I decided to make "easy" parts, that just required turning. I checked all of my bins, and found that I didn't have any round steel large enough in diameter to make the outer 'drum'.---I did however have a piece of 2" diameter cast grey iron left over from the cylinder on the Rupnow Vertical engine. I decided to use it. This has a good side to it, in that it won't need a bushing where it rides on the revolving line-shaft when the line-shaft is turning and the pulley is not turning. The bad side is that cast iron isn't the strongest metal going, so I left the rim a bit thicker than my original intent. the finished diameter is now 1.725". I did find a piece of cold rolled steel to make the set collar from. That set collar keeps the drum from "drifting away" from the correct position.

Brian Rupnow · « **Reply #14 on:** October 04, 2016, 04:37:15 PM »

J.L.--If you can wait for a couple of days, I will post a package of all the detail drawings for what I am doing. I want to make sure this thing works as intended before I put up the drawings.--Brian

Brian Rupnow · « **Reply #15 on:** October 04, 2016, 10:57:26 PM »

Well, it sorta/kinda works. The angle on the contact surfaces which I arbitrarily picked as being 45 degrees is too steep. I have a 45 degree angle on the nose of that 3/4" diameter slider and with the lathe running at about 60 rpm I can hold the pulley drum from rotating with a finger. If I use my other hand to force that 3/4" diameter slider against the "arms", the shoes do expand and make the drum rotate. However, I am sure a shallower angle will make things work with a lot less effort.

Brian Rupnow · « **Reply #16 on:** October 04, 2016, 11:57:17 PM »

I changed the angle on the end of that 3/4" slider to an included angle of 60 degrees instead of 90 degrees, and it made a tremendous difference. The clutch is working just as I hoped it would. You have to keep in mind that those sliding shoes only have to move about .015" to make the difference between engaged and disengaged. If they had to travel any real distance, then I'm sure they would "cock over" and bind badly. I can feel a video coming on---

90LX_Notch · « **Reply #17 on:** October 05, 2016, 01:49:11 AM »

Brian-

Nicely done.

Based on what I see, I do think 1/2 scale is feasible. The challenge is of course the t-slot. However, I believe that John's diarama would work out to be 3/4 scale of your clutch (3/16 vs 1/4 shaft). This makes it very attainable. At 1/2 scale the 4-40 screws work out to 0-80 and at 3/4 scale they would be 2-56. 0-80 can be nerve wracking; 2-56 isn't bad.

-Bob

J.L. · « **Reply #18 on:** October 05, 2016, 02:32:05 AM »

Nicely don Brian!

Brian, if I may, through you to Bob.

Hi Bob,
The diorama scale is 1/12.
John

90LX_Notch · « **Reply #19 on:** October 05, 2016, 02:53:01 AM »

John-

I understand. I'm refering to Brian's clutch as 1:1. Your 3/16 shaft would scale to 3/4 of Brian's clutch. He used a 1/4 inch shaft.

-Bob

Brian Rupnow · « **Reply #20 on:** October 05, 2016, 04:18:19 PM »

This morning I took successive cuts from the outside diameter of the coned 3/4" piece until I had it down to a diameter that would just slide between the arms under slight pressure to open them wider and engage the sliding shoes with the clutch drum. This was not something that could really be calculated with any accuracy. It was purely "turn a little bit and then try it" engineering. With my model, the "ideal diameter" should have been 0.520" diameter. In actuality, it was exactly 0.500" diameter, which is pretty darned close, considering the build up of tolerances and the shape of the arms. I have provided two pictures, one showing the clutch in the "not engaged" position--The "Not engaged" position shows a gap of 0.100" between the nose of the sliding cone and the brass hub. The "engaged" position shows 0 gap between the nose of the sliding cone and the brass hub. And yes, that is a Canadian quarter laying in the foreground to give e sense of scale. Our quarter is the same size as an American quarter .

Brian Rupnow · « **Reply #21 on:** October 05, 2016, 04:45:12 PM »

It doesn't always start with a pretty 3D cad model. Sometimes when I'm hashing out exactly what I'll do next, I resort to good old pencil sketches to determine the direction I will take. I will now go from this preliminary sketch to a 3D cad model where I can input all the math data to create accurate models and detail drawings from.

Brian Rupnow · « **Reply #22 on:** October 05, 2016, 06:43:38 PM »

So, we end up looking like this. The panther pink pulley is driven by an o-ring drive belt from one of my engines, to turn the lineshaft. When the clutch is not engaged, the green pulley drum just sets there and does not revolve. When the clutch is engaged, the pulley drum does turn, and will drive an o-ring belt that powers one of my "work, work, work mechanisms, probably the moving staircase.

10KPete · « **Reply #23 on:** October 05, 2016, 07:38:44 PM »

That's a pretty neat bit of work, Brian. I'm looking forward to you building that into one of your engine/load set-ups. One small concern, that probably won't mean much for the limited service intended, is the lack of compliance or elasticity in the mechanism. A tiny amount of wear in the clutch surfaces or the actuator cone and arms will result in no engagement. Maybe the arms could be lengthened and made thin to act a springs......

Pete

Brian Rupnow · « **Reply #24 on:** October 06, 2016, 12:11:39 AM »

That's enough for today. My back hurts!! Tomorrow, I hope to make the lever mechanism that will engage and disengage the clutch.

Brian Rupnow · « **Reply #25 on:** October 06, 2016, 12:26:36 AM »

Quote from: 10KPete on October 05, 2016, 07:38:44 PM

That's a pretty neat bit of work, Brian. I'm looking forward to you building that into one of your engine/load set-ups. One small concern, that probably won't mean much for the limited service intended, is the lack of compliance or elasticity in the mechanism. A tiny amount of wear in the clutch surfaces or the actuator cone and arms will result in no engagement. Maybe the arms could be lengthened and made thin to act a springs......

Pete

Pete--If you go back and look at reply #9 you will see that on the original line shaft clutches, the tapered bits on the end of the arms have a thread in them. I think that was how they adjusted to compensate for wear and to make sure that both arms extended equally. Of course, here in "Model world" I don't have to be quite as concerned with wear. Now that I have actually made the arms, I see that I could have incorporated a threaded fastener into them to provide the same service, however, as in most things I build, this is my 'prototype", even if I never build another one. Before this week, I always wondered about this type of clutch and how it actually worked. But----There are about a million mechanical things floating around in the back of my mind that I kind of wonder about, but unless I make a conscious effort to recreate the design and build one myself, they are only vague thoughts. One thing I can say for this clutch, based on my experience so far---There isn't much "between" to this clutch. It's either ON or its OFF. Probably it transfers less shock to the driven machinery than a dog clutch would, but there isn't a whole lot of "slippage". There doesn't seem to be any replaceable lining on the friction shoes either from what I can see in the photograph in post #9.

gerritv · « **Reply #26 on:** October 06, 2016, 02:42:06 AM »

Considering how ubiquitous these devices were at one time it is surprisingly difficult to find details. I even tried trolling old patents as well with little luck.

J.L. · « **Reply #27 on:** October 06, 2016, 06:08:14 PM »

Hi Brian,

Wonderful work Brian. I have been hammering out a prototype as well. Drawings are up on the diorama thread.

Great weather as we approach Thanksgiving.

Cheers...John

Brian Rupnow · « **Reply #28 on:** October 06, 2016, 07:43:08 PM »

Jeez John--You don't fool around, do you!!! Nice work on your clutch. Mine is all finished and seems to work well. If I can find the energy to get things set up, I'll post a video. I think since I already have my Kerzel hit and miss out on the bench I will use it as a driver, thru the newly made clutch, to the steel ball elevating staircase. if everything works as I hope, I will put up a link to the drawings.-- Most line shaft clutches I remember seeing had the line shaft overhead, and a long handle that hung down for the machine operator to pull to engage the clutch. Of course my memories are from sawmill stuff in the 1950's.---Brian

J.L. · « **Reply #29 on:** October 06, 2016, 09:10:12 PM »

Hi Brian,
Thanks!
Brian, I've got to get my head into your videos and posts. I apologize for not taking time to search them out.
Cheers...John

Brian Rupnow · « **Reply #30 on:** October 06, 2016, 09:18:13 PM »

Well, I'm all set up and ready to go. I realized that the drive wasn't going to work on the Kerzel, because the gas tank was in the way, so I stuck the Rupnow Vertical in there instead. However, I've ran into technical difficulties. My clutch which worked so good when testing it in the lathe is letting me down in "actual circumstances". The coned hub which the lever moves back and forth is supposed to turn freely, so that when it is engaged it doesn't see any load from the lever. When engaged it is supposed to turn with with the central hub and arms. For some reason that isn't happening, and it is creating drag where there shouldn't be drag, and making my drive belts slip. I'm too tired to fight with it anymore today, so I am going to clean up, go upstairs, and drink wine.

Brian Rupnow · « **Reply #31 on:** October 06, 2016, 11:01:47 PM »

Right now I'm not too impressed with my clutch. In all my years in engineering I have never had particularly great results with sliding mechanisms. It seems that nothing has fundamentally changed. Pivots rule!! I will make one more stab at making my clutch work tomorrow. if I don't have immediate success, there is going to be a design change. I haven't lost all that much if I go to a total design change. The frame and pulley have the most work in them, and that will stay. I have to think on what to do next.---Brian

Captain Jerry · « **Reply #32 on:** October 07, 2016, 04:23:05 PM »

Brian -- I have worked on some of these things a long while back so if you don't mind a couple of suggestions, here is what I would look at. First is the width of the groove in the sliding part. There needs to be plenty of room or even some slop to prevent the engagement pins from binding in the slot. I have seen some that used a square or rectangular sliding block in the groove attached to the pins. Second is the width of the flat section on the engagement cone. It must be wide enough that the clutch lever arms can slide onto the flat so that they don't offer any back force on the slider.

On those that I remember, the clutch was overhead so that the weight of the handle returned it to vertical after engagement and there was still plenty of movement to disengage. Is it possible that your model with the handle on top is keeping some pressure on the engagement face of the groove?

Jerry

Brian Rupnow · « **Reply #33 on:** October 07, 2016, 06:39:15 PM »

Jerry--right now it's all a matter of fits and tolerances. I ream all of the holes which shafts turn in, and anything else I deem as being critical. When it is all assembled, the stack up of tolerances introduces binding where there shouldn't be any binding. I took it all apart this morning and loosened everything up a bit. Hopefully when I reassemble things, it will work better.

Brian Rupnow · « **Reply #34 on:** October 07, 2016, 08:35:40 PM »

So there we have it--An operating line shaft style, expanding shoe drum clutch. This was not a great effort in terms of engineering, as I followed a design from long ago. The problems came in reducing everything in size to end up with a 1/4" shaft and a 1.7" outside diameter drum. The original full sized clutches had better proportions, and the contact surfaces on the end of the arms which the sliding cone bears against to operate the clutch had threaded ramps, which could be used to set the pressure on the shoes, and equal travel on each arm. My initial attempt to operate this clutch yesterday failed because there were too many points of "binding" in all of the mechanicals. I took it all apart this morning, added a few clearances to critical areas, and made a new coned slider out of O1 material which I flame hardened. That seemed to do the trick, and as the video shows, the clutch does operate.

<a href="https://www.youtube.com/watch?v=y5m5SrYTjFk" target="_blank">http://www.youtube.com/watch?v=y5m5SrYTjFk</a>

crueby · « **Reply #35 on:** October 07, 2016, 09:43:03 PM »

That works quite well - thanks for sharing all the info and build with us!

Now, you need to build the rest of the diorama like John did...

Brian Rupnow · « **Reply #36 on:** October 07, 2016, 09:49:56 PM »

Crueby--John is doing such a masterful job that I wouldn't even try to compete with his wonderful build. I just needed a little "filler job" to get me thru this week. I looked at hundreds of line shaft type clutches on the the internet, and to be truthful, I never did see one exactly like I have built. From what I could see, the majority of the expanding shoe type clutches used a full internal band with a split in it, and a lever operated cam to wedge the band open and engage the clutch.

Brian Rupnow · « **Reply #37 on:** October 08, 2016, 02:18:07 AM »

Having built one line shaft type clutch, which works, but is far from perfect (I hate sliding parts), I have taken some advice from Charles Lamont on HMEM and reworked the design so the clutch shoes are operated by pivoting levers. The shoes still slide in a milled rectangular slot, but the arms which operate the levers are pivoted at one end, and have an adjustment screw at the other end to set the pressure they exert on the inside of the drum, and the two separate sliding shoes can be equalized. Force is transferred from the pivoting arms via a cross-pin which transfers movement to the sliding shoes. The overall diameter is the same as the clutch which I just built and made the video of. I am quite excited about this design, and probably will make a clutch to this design in the coming weeks.

sbwhart · « **Reply #38 on:** October 08, 2016, 07:11:57 AM »

Hi Brian

Bin following this interesting project along, and what a great result, look forward to following your MKII progress.

Thanks for showing

Stew

Brian Rupnow · « **Reply #39 on:** October 08, 2016, 02:39:21 PM »

This is the same pivoting style clutch with the shoes maximized for thickness and for width. this gives more than twice as much shoe contact area with the inside of the drum.

Brian Rupnow · « **Reply #40 on:** October 08, 2016, 07:02:05 PM »

Okay--Hang onto yer pants--Here we go!!!---

Brian Rupnow · « **Reply #41 on:** October 08, 2016, 07:02:58 PM »

And a couple more--

crueby · « **Reply #42 on:** October 08, 2016, 07:46:59 PM »

Very nice! Another set for the files for future projects... whatever may need a line shaft!

Brian Rupnow · « **Reply #43 on:** October 09, 2016, 04:32:29 PM »

I have a much better feeling about this new pivoting clutch. The two main outer shells that bolt together and the adjustable swinging arms are finished. Probably I will make the sliding shoes next.

gerritv · « **Reply #44 on:** October 09, 2016, 08:06:32 PM »

A wonderful illustration of iterative design.

Brian Rupnow · « **Reply #45 on:** October 09, 2016, 10:01:13 PM »

Quote from: gerritv on October 09, 2016, 08:06:32 PM

A wonderful illustration of iterative design.

Thank you. I had to get my dictionary out and look up "iterative" to see what it meant!!!-Thanksgiving was cancelled here today. Good wife woke up sick with the flue, which prompted a flurry of telephone calls to children and grandchildren telling them not to come here today. Wife spent the day in bed. I spent 12 hours in my shop. This new clutch has so many parts fitted into such a small space it reminds me of one of those Kachina dolls.

Brian Rupnow · « **Reply #46 on:** October 09, 2016, 11:00:52 PM »

So, after a full days work, this is the new clutch in which the shoes are expanded by pivoting levers. I have one "in process" shot of the shoes being machined as one piece from a 1 1/2" diameter piece of steel. They were fitted and split into two pieces after all of the machining. It works so smoothly I had to make a movie of it.

<a href="https://www.youtube.com/watch?v=szABU_9WM4o" target="_blank">http://www.youtube.com/watch?v=szABU_9WM4o</a>

Brian Rupnow · « **Reply #47 on:** October 10, 2016, 09:57:45 PM »

And--A short explanation video about the fully assembled clutch---

<a href="https://www.youtube.com/watch?v=lGXQXf7ZGSY" target="_blank">http://www.youtube.com/watch?v=lGXQXf7ZGSY</a>

Brian Rupnow · « **Reply #48 on:** October 10, 2016, 10:33:15 PM »

Final "run" video of clutch version #2

<a href="https://www.youtube.com/watch?v=hPuQ2R0E8Ys" target="_blank">http://www.youtube.com/watch?v=hPuQ2R0E8Ys</a>

10KPete · « **Reply #49 on:** October 11, 2016, 01:12:49 AM »

Brian, may I make a suggestion? The video where you explain the most recent model of your clutch, without it running, is taken too far away from the clutch. The features you are explaining can not be seen. If you position the camera so the clutch fills the frame then maybe we could see the parts.

Following along with great interest,

Pete

Brian Rupnow · « **Reply #50 on:** October 11, 2016, 01:17:31 PM »

Sorry, Pete--I'm just not going to make it in this life as a photographer. However, to see everything more clearly, see post 37 and 39. That shows 95% of what I built.---Brian

Brian Rupnow · « **Reply #51 on:** October 12, 2016, 01:41:45 AM »

This was a fun project, even if the first attempt gave less than stellar results. I really like the second, final version. I was so burned out on machining from my July thrash on the vertical engine that I haven't wanted to do any machining until last week when this came up. The total duration of this project was 6 days, including the first version which I wasn't really happy with. It is getting more and more difficult to find projects that interest me. I think I'm up to 23 or 24 finished engines now, 12 of which are i.c. and 11 or 12 that are steam/air powered. I'm tired of building engines. I want to build another interesting machine to drive with my engines. Currently I have the slinky machine, the bubble blowing machine, the ball elevator that appears in the video, a sawmill, a buzz saw, a wood splitter, a piston pump, a gear pump, an oil well "grass-hopper" pump, a pile driver, and a semi-complete marble automation. I think that perhaps I will design and build a "walking beam conveyor" for my next project. They are fascinating to watch, and just different enough to be interesting.

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Author Topic: Line-Shaft Clutch (Read 15511 times)