Quick Change Collet

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dansawyer

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Attached are pictures of a quick change collet setup. One picture is the closing mechanism, the second is a 5C collet closer with 5C collet, barely visable, and a piece of 1 inch rod. The mechanism actually works, but is very fussy. There is a pin in the mechanism that locks the mechanism, knurled part in the picture, to the part that attaches directly to the spindle. This adjustment is very sensitive, if it is loose then the mechanism does not close tightly. A very small change it tightening, actual closing rod to actual 5C collet, may adjust from too loose to too tight. (As a note on this setup the closing rod is parhaps 1/2 inch too short. A project will be to make a new one. )
Does anyone have experience with this type of mechanism? Is there a good way to better estimate too tight or too loose?
(Overall I am pleased with the result. When a precise rod is placed in a collet overall run out, spindle, collet closer, collet, and rod, is a few tenths. )
 

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dansawyer said:
Attached are pictures of a quick change collet setup. One picture is the closing mechanism, the second is a 5C collet closer with 5C collet, barely visable, and a piece of 1 inch rod. The mechanism actually works, but is very fussy. There is a pin in the mechanism that locks the mechanism, knurled part in the picture, to the part that attaches directly to the spindle. This adjustment is very sensitive, if it is loose then the mechanism does not close tightly. A very small change it tightening, actual closing rod to actual 5C collet, may adjust from too loose to too tight. (As a note on this setup the closing rod is parhaps 1/2 inch too short. A project will be to make a new one. )
Does anyone have experience with this type of mechanism? Is there a good way to better estimate too tight or too loose?
(Overall I am pleased with the result. When a precise rod is placed in a collet overall run out, spindle, collet closer, collet, and rod, is a few tenths. )
Click to expand...
The pin that locks the knurled part after it has been set to the right tension should be turned so that the spring can drop pin into the hole to keep it the same
position . It is the round knurled part with a flat on it. The set screw is what holds it from dropping into the hole.
Jimsehr
 
It's called a lever-action collet closer, looks like a Royal. They're not usually that difficult to get adjusted, put a part in the collet, rotate the locking pin to the disengaged position and tighten the draw-tube adjustment while working the lever. Once the lever snaps, firmly gripping the part, rotate the locking pin to drop in and lock the adjustment.
 
Thank you. This is beginning to make sense. Rotating the knurled adjuster on the actuator changes the collet grip purchase on the draw tube. The actuator is very sensitive to this draw tube adjustment. I worked with this for a couple of hours and found that with a little care the whole thing worked very smoothly. Even better yet the 5C collets held work to much tolerances then a 3 jaw and was much much faster than a 4 jaw.
 
dansawyer said:
Thank you. This is beginning to make sense. Rotating the knurled adjuster on the actuator changes the collet grip purchase on the draw tube. The actuator is very sensitive to this draw tube adjustment. I worked with this for a couple of hours and found that with a little care the whole thing worked very smoothly. Even better yet the 5C collets held work to much tolerances then a 3 jaw and was much much faster than a 4 jaw.
Click to expand...
You might want to look into 5c emergency collets , 5c step collets and 5c expanding collet’s. And there are square , hex and dead length collets.
Jimsehr
And I have loaded thousands of parts with the spindle running.
 
Welcome to the club! You will find yourself looking for ways to use a collet instead of the 3-jaw.
 
It's a JFK brand collet closer. As of six months ago, they were still in business and showed no sign of going away.
Small, family business and very helpful.

One thing that may not be obvious is that the drive flange (my name), attached to the back of the spindle, should be adjusted for minimum radial runout using the setscrews. Don't just stick it on there and tighten the setscrews, Runout will cause the actuator lever to vibrate and becomes generally unpleasant.

 
extropic said:
It's a JFK brand collet closer. As of six months ago, they were still in business and showed no sign of going away.
Small, family business and very helpful.

One thing that may not be obvious is that the drive flange (my name), attached to the back of the spindle, should be adjusted for minimum radial runout using the setscrews. Don't just stick it on there and tighten the setscrews, Runout will cause the actuator lever to vibrate and becomes generally unpleasant.

Click to expand...
Thank you. I was fairly lucky that the first pass was fairly accurate. My drive flange is machined on the spindle fitting to be a good fit. The inside diameter is a slip fit and there is an internal coller that mates to the spindle end. The result is operation is quite smooth, there is only minor handle movement.
That brings up a question, the bearing has a fair amount of play. I do not believe there is an issue at the moment, however I was wondering if that was going to introduce an issue downstream.
 
If it works fine, I would go ahead and use it.

If you need to be certain it's top notch, call JFK. I'm pretty sure you could send that part for their evaluation.

I got my closer by buying an incomplete unit off eBay. It was very grungy when received but cleaned up surprisingly well. My bearing was very rough and hard to turn. After cleaning with diesel fuel, it seems the problem was just coagulated lubricant. The bearing felt pretty good after cleaning. I took it, along with all the other parts I had, to JFK to have them make the unit whole. I specifically asked about the bearing and Jose said it seemed fine. YMMV
 
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