Need Ideas For Collet Stop Design

[omni_dilletante]

I find myself in need of a collet stop for 2A collets which do not have an internal thread.

The cavity in the collet is 0.680" in diameter and about 2" long.

I need some ideas on how to make a simple yet functional collet stop. I would like a stop that fits inside the collet and not on the collet closer.

The google has provided me with a few examples, but I am hoping someone on this board has a better idea:

This example is a bit complicated, not sure how I would make the split part:



This example is for a 3C collet (even smaller than mine) but I am not entirely sure how it works. The only thing I can find about it is this picture:



This is a Speed Stop, which is made here in town, but I don't think they make one small enough for my collet. (I tried to email them, but the address on their website does not work):




This example is for a shaublin 20mm collet that uses ball bearings and tapered shaft to grip the inside of the collet. I have no idea how I would drill a hole that would allow the ball bearing to extend to the collet, but not fall out completely.



This commercial collet stop looks way too complicated to scale down to fit inside my collet:



I appreciate your help.

 

[T Bredehoft]

How about, a plug, just under the ID of the collets, Drill and tap for a pipe plug, Saw length wise past the plug hole in X pattern, insert plug in collet, adjust for correct depth and tighten pipe plug. You could have a short set screw in the other end for fine adjustment.

 

[chips&more]

You can hold 4 equal sized pieces of square stock bundled together in a 4 jaw chuck on the lathe. Then do your hole and OD machining. That way no need to do any saw splitting…Dave

 

[Wreck™Wreck]

Why do you not want a through spindle stop?

On occasion I use a Hardinge turret lathe that uses 5C collets, this is just a beautiful little machine, 1 1/8" through and nearly silent when running ( 1" max collet diameter) the back of the spindle past the closer has a taper so I made a tapered aluminum part the fits this taper with a hole drilled through the center and some set screws to hold a 1/2" rod as a spindle stop. I just hammer it into the rear of the spindle like a Morse taper drill in a tail stock. Install collet and part and set the stop, make parts, When done remove collett and place a piece of bar through the front of the spindle and drive the tapered part out, nothing could be simpler.

 

[RJSakowski]

The first modification that I made to my Grizzly 602 lathe was to thread the back end of the spindle for a work stop. The stop consists of an adapter with 1-1/8"-16 external thread and 3/8-16 internal threads and lengths of 3/8-16" threaded rod with various ends to suit the work piece need.

Here is the link to the post on that subject.
http://www.hobby-machinist.com/threads/lathe-headstock-work-stop-g0602.32809/#post-276973

 

[omni_dilletante]

You can hold 4 equal sized pieces of square stock bundled together in a 4 jaw chuck on the lathe. Then do your hole and OD machining. That way no need to do any saw splitting…Dave

Perfect.

That was exactly the simplification I needed.

You are brilliant. Thank you.

 

[TakeDeadAim]

I think the simplest way to do it would be to turn a piece of bronze or brass that just slides into the collett, drill and tap the back side for a set screw and split the stop half way up into 4 segments the set screw should expand and lock the piece into the collett. Thread the other end for a stop screw and use a lock nut to hold it in place. IT's really just a simple example of the ones you submitted as examples.

 

[kd4gij]

Easiest way get a 3/4" expanding arbor and turn it down. A 5/8" might work.

 

[Kernbigo]

here is a couple i made when i worked in the shop