Author Topic: How does this clutch work?  (Read 6224 times)

Offline Brian Rupnow

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Re: How does this clutch work?
« Reply #15 on: September 21, 2018, 03:40:53 PM »
Non of my slitting saws are large enough to cut these apart if they were all machined on a single piece of stock.

Offline Brian Rupnow

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Re: How does this clutch work?
« Reply #16 on: September 21, 2018, 03:59:16 PM »
Might be simpler if I welded all three plates together first on the non critical side.--Then machine that area of plate and the weld off as my last step to leave me with three identical plates.

Offline Brian Rupnow

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Re: How does this clutch work?
« Reply #17 on: September 21, 2018, 04:22:11 PM »
Since these parts see the most wear as the clutch engages and disengages, I would make them out of 01 material, flame harden and quench, then draw them back to a stage of non brittleness in my kitchen oven for two hours at 350 degrees. 01 material is a bit harder to machine in its unhardened state than mild steel, but only a bit. It can be worked with HSS tooling.

Offline Alan Haisley

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Re: How does this clutch work?
« Reply #18 on: September 21, 2018, 05:52:17 PM »
I think this is an ingenious design for a clutch. The only issue with it that I see is that while it may be great for 1" diameter shafts and larger, it would be incredibly difficult to miniaturize it to work on a 3/8" shaft like most of my engines have. True, most of the components are simply "turnings" that would present no difficulty to miniaturize, but the comma shaped pieces would get so small I don't think I could machine them accurately. Too bad, because it is a really slick design.
You're amazing, Brian  :)
First you decide that something is too hard for you to do and then you go ahead and figure out how to do it anyway.  :praise2:
If you are going to build this clutch I certainly want to look over your shoulder while you do it.
Alan
Near Raleigh, NC, USA

Offline Brian Rupnow

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Re: How does this clutch work?
« Reply #19 on: September 21, 2018, 06:55:33 PM »
Alan--It's okay---I'm going a bit mad these days. I don't have any real design work, I'm waiting for all my authors to publish something new so I'll have a good book to read. My yard-work is all caught up, and I'm too old to drink whiskey or chase women. I did have the only other model engineer in Barrie over for a couple of hours this morning and we sat and talked machinery and told lies to each other for a while but he's gone home now. I may build this clutch, #1-Just to see if I can, and #2-to give me something to do other than watch the idiot box.---Brian

Offline crueby

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Re: How does this clutch work?
« Reply #20 on: September 21, 2018, 07:32:19 PM »
Alan--It's okay---I'm going a bit mad these days. I don't have any real design work, I'm waiting for all my authors to publish something new so I'll have a good book to read. My yard-work is all caught up, and I'm too old to drink whiskey or chase women. I did have the only other model engineer in Barrie over for a couple of hours this morning and we sat and talked machinery and told lies to each other for a while but he's gone home now. I may build this clutch, #1-Just to see if I can, and #2-to give me something to do other than watch the idiot box.---Brian
Brian, perhaps you may need a large model project, a vehicle or construction machine - great variety of parts, and many of them, something to keep you busy over a longer time. Lots of plan books (Kozo, etc) for locos and other types, maybe an early style Formula 1 or Indy style car...

Offline Brian Rupnow

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Re: How does this clutch work?
« Reply #21 on: September 21, 2018, 08:58:23 PM »
I decided that shrinking the clutch to 1/3 of it's original size was just going to make components too small, so I just spent a couple of hours shrinking everything to 1/2 size. In the large version it is configured for a 1" diameter shaft. In the small version it is configured for a 1/2" diameter shaft.
This brings it into a more "doable" size range.

Offline Brian Rupnow

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Re: How does this clutch work?
« Reply #22 on: September 21, 2018, 09:01:01 PM »
Chris--If I ever did what you advise, I would work myself right to death trying to finish it. I get so "into" whatever I am making, I find it hard to take time out to eat or sleep. I like these smaller projects that have a 30 day timeline.

Offline BillTodd

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Re: How does this clutch work?
« Reply #23 on: September 22, 2018, 12:19:31 AM »
I don't think you need the :over centre' locking mechanism Brian .

Unless your clutch friction material is very compliant, and able to provide the traction pressure itself , the clutch will lack grip when over the peak . The collet closer on my hardinge uses pretty much the same finger lever as your design but has a flat after the expanding section , so once the closing force reaches maximum it stays at that level with the lever held in place by the friction of the fingers on thr flat section only.

Bill
Bill
wy omnibus Latinis taurus stercore?

Offline Brian Rupnow

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Re: How does this clutch work?
« Reply #24 on: September 22, 2018, 01:08:42 AM »
Bill--You could be right---but---Open the link in the very first post of this thread and see what they did. I probably have the reduced diameter of the expander cone too exaggerated. I'll take a closer look at that in the morning.
« Last Edit: September 22, 2018, 01:16:29 AM by Brian Rupnow »

Offline john mills

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Re: How does this clutch work?
« Reply #25 on: September 22, 2018, 10:08:03 AM »
what does the spring do   does it not give some compressibility and give to control pressure on the clutch facing?

Offline dieselpilot

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Re: How does this clutch work?
« Reply #26 on: September 22, 2018, 12:32:00 PM »
what does the spring do   does it not give some compressibility and give to control pressure on the clutch facing?

This is exactly the purpose of the spring in this case. Adjustment described in the text controls engagement point, so to change pressure you'd really have to change spring rate assuming the cam and cone are fixed.
« Last Edit: September 22, 2018, 12:37:17 PM by dieselpilot »

Offline Brian Rupnow

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Re: How does this clutch work?
« Reply #27 on: September 22, 2018, 04:07:51 PM »
In about two minutes I am going to jump up and grab a piece of mild steel and make this expander cone. It's cold outside and good wife and visiting daughter are off to the mall. I don't have any 01 stock this large in diameter, so I'm not going to harden it.

Offline Brian Rupnow

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Re: How does this clutch work?
« Reply #28 on: September 22, 2018, 06:18:26 PM »
First part made---the expander hub. I made it from a scrap end of material that I had left over from something.

Offline Brian Rupnow

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Re: How does this clutch work?
« Reply #29 on: September 23, 2018, 12:06:31 AM »
I was originally going to make this clutch with three comma shaped arms. However, looking at the slitting saws I have, I decided to make it with four comma shape arms. This way I can cut the 1/8" wide slots in the blue hub all the way across the face.