Author Topic: Sometimes too much length is a bad thing.....  (Read 362 times)

Online orabanda

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Sometimes too much length is a bad thing.....
« on: 16.05. 2019 14:28 »
That got your attention!

Making a clutch for a Shooting Star under construction. Using the standard BSA clutch crowded roller bearing arrangement.

I trial fitted the clutch to an A10; there was a problem.

The hub turned freely until the centre nut was tightened; then it would bind and release as rotated; notchy.

I checked all the obvious interference areas, but couldn't find the cause.

Then decided to get back to basics, and measured the length of each 1/4"roller with a micrometer, and found the problem,

Two of the rollers (bought as a set) were 0.008" longer.

Replaced them, and now the clutch turns freely!

A reminder to check everything.


Richard

Offline A10 JWO

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Re: Sometimes too much length is a bad thing.....
« Reply #1 on: 16.05. 2019 18:15 »
My 4 new clutch springs were all different lengths, one by 1/4". Says it all. 

Online RDfella

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Re: Sometimes too much length is a bad thing.....
« Reply #2 on: 16.05. 2019 19:14 »
When you have to check other people's work it doesn't say much for their quality control or attitude.
'49 B31, '49 M21, '53 DOT, '58 Flash, '00 Firestorm, Weslake sprint bike.

Offline IVO

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Re: Sometimes too much length is a bad thing.....
« Reply #3 on: 21.05. 2019 14:33 »
 Reminds me of Aristotle's - Pleasure in the job puts perfection in the work.
   
 Ivo
 
   



Online coater87

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Re: Sometimes too much length is a bad thing.....
« Reply #4 on: 13.06. 2019 06:27 »
Richard,

 What are you using for a. Plate stack up?

 I see everyone else uses 6 frictiond. I a. Using 7 because if i dont i run out of room on the pressure plate.
In other words pressire plate is bottomed out and the clutch plates are still loose.

I am thinking about stacking sfsfsfsfsfs, im missing something because you get away with six fibers and i need the entire stch of 7  *????*
What am i doing wrong here?

Lee
Central Wisconsin in the U.S.

Online orabanda

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Re: Sometimes too much length is a bad thing.....
« Reply #5 on: 13.06. 2019 06:42 »
Hi Lee,
Nothing wrong with your set-up; I suspect your inner clutch hub is sitting lower than mine do. The position (height) of the inner hub is determined by how you engineer the inner spline arrangement.

The arrangement "sfsfsfsfsfs" should be the perfect fix.

Confirm that the inner hub is not sitting too low relative to the basket; if this is the case, then the bottom fibre plate would hang up on the basket and would have insufficient contact with the steel plate below. This could be resolved by having 2 steel plates back to back below the bottom fibre plate; I have had to do this occasionally. Alternatively, if there is a thicker steel plate in your collection, put it on the bottom.

Richard

Online coater87

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Re: Sometimes too much length is a bad thing.....
« Reply #6 on: 13.06. 2019 17:41 »
 Thank you Richard,

 I think maybe my bottom friction plate was getting pinched in the slide groove when the clutch got warm. I am going to install all new plates and raise that bottom friction more.

 I will keep you informed on this.

 Lee
Central Wisconsin in the U.S.