5C Collet Stop

Cobra

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When making studs and sleeves for the Cross-Twin engine I was having trouble with consistency in length using the collet chuck. I was using a spindle stop but it seems that the clamping of the collet in the chuck was moving the parts. I have looked at buying a stop for the collets for some time but decided yesterday to have a go at making my own. I used my new favorite steel for the body of the stop and drill rod for the movable stop. Stressproof steel is so nice to work with.
The thread on the inside of the 5C is an unusual size -- 1.041-24.
There are some of the stops that are threaded but I wanted a sliding stop that would be held with a set screw.

Sketched up the parts -

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Started from a 1-1/2" bar.

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This steel cuts so nice!

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Cut the 1.041" for the threads with the relief groove.

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Cutting the 24 tpi threads. Test fit the thread with a number of the collets as some are tighter than others.

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Body has been threaded, drilled and reamed for a 3/8" sliding stop. Tapping the #10-32 set screw so that the sliding stop can be used to finish the lathe work and hold the body to mill the flats for the wrench.

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Finishing on the lathe.

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Using a collet block on the sliding stop to hold for milling the flats.

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Not tested yet but high hopes that it will work better than the long spindle stop.

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Attachments

  • 5C Collet Stop.pdf
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Looks good even better then the screw adjusted kind . Fine adjustments may be accomplished with a tapped hole in the adjuster rod . Could be done even mounted in the lathe that way. Just trying to help , like whole concept ill be building one , I love 5C collet with lever . Good build thanks
 
Looks good even better then the screw adjusted kind . Fine adjustments may be accomplished with a tapped hole in the adjuster rod . Could be done even mounted in the lathe that way. Just trying to help , like whole concept ill be building one , I love 5C collet with lever . Good build thanks

Thanks. I think I am going to need an extension tube to fit longer pieces.
 
Nicely done, I have one that I purchased but it is out of aluminum so galls a bit. I will probably machine something similar to what you have out of steel, and I may incorporate a separate larger 20TPI thread unit for a fine adjust.. Thank you for posting what the drawings and the pictures.

I have had some issues in the past in using these stops in that the position can shift slightly based on how tightly the collet is pulled into the chuck. I would assume a collet closer is more reproducible. I use a Bison 5C chuck which seems to be more reproducible as to the final 5C clamping position.
Mark
 
I got a chance to try it out today. I love it when something you make in the shop works the way it's supposed to.
First try with the long spindle stop gave four pieces that were +/- 0.009.
Re-made the four of them today and they were +/- 0.0003.
Also learned a lesson that even with the stop in place, you don't really need to reef on the tightening of the collet chuck.
 
And idea you can do on the stop is add a little dimple relief for when you have to work on the back of a part the may have a tit on it.
 
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