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View Full Version : My collet closer saga



tmc_31
11-01-2009, 06:10 PM
Hi all,

Now that I have finally got Photobucket figured out, I can post these:

http://i663.photobucket.com/albums/uu351/tmc_31/thecolletcloser014Small.jpg

http://i663.photobucket.com/albums/uu351/tmc_31/thecolletcloser016Small.jpg

http://i663.photobucket.com/albums/uu351/tmc_31/thecolletcloser017Small.jpg

http://i663.photobucket.com/albums/uu351/tmc_31/thecolletcloser019Small.jpg

This the final result of my Collet Closer build. Since these photos were taken, I have knurled the top of the hand wheel so I could get a little better grip on it.

Thanks to all who helped with comments, criticisms and advise

Tim

PS,I purchased the 5MT-5C nose piece from the fine folks at grizzly

Black_Moons
11-02-2009, 03:12 AM
Nice closer, how is your collet holder registering in the spindle?

spkrman15
11-02-2009, 11:16 AM
Hey Tim,

Nice work. Do you find that tightening by hand is enough?

Rob :)

Doozer
11-02-2009, 11:21 AM
Consider using a thrust bearing and moving the handwheel out some more for finger clearance.

--Doozer

tmc_31
11-02-2009, 12:19 PM
Hi guys,

http://i663.photobucket.com/albums/uu351/tmc_31/thecolletcloserSmall.jpg

Black_moons,

Thanks man, I chucked a small wrist pin (new, .8123 dia. ) in a 13/16" collet to check and see what kind of run-out I could expect. I indicated within .0015 TIR. Then I swapped the wrist pin end for end and again indicated within .0015. So the runout and repeatability are much better than my three jaw chuck. It is not that good on rough stock. I tried a piece of 5/8" CR and got within .002. All measurements were taken 1" from the collet nose.

spkrman15,

Yes, tightens very well as long as the stock is on size or slightly larger. Apparently the grip range of the 5C collets is somewhat limited. They are good for -.001 to +.004. My hand was slipping on the handwheel as I tightened the closer with the slick finish on the rim. Last night I knurled the handwheel to try to alleviate this problem. This was my second attempt at knurling (I did try a test piece before sacrificing my closer to the machining gods).

Doozer,

I have thought about using a thrust bearing and I may add one later if I get to using the collet system a lot. I think I can add one without too much trouble. As to the spacing of the handwheel to the back side of the headstock, yes it is a little close (1/2") but I can live with it. The knurling makes it much easier to operate.

Tim

Black_Moons
11-02-2009, 04:56 PM
Very nice knurl! Odd how the camera sorta makes it look inside out.. (looks like recessed diamonds and raised vallys)

Walter
11-02-2009, 06:15 PM
TMC,

Can you shoot a picture of the face of the hand wheel where it contacts the end of the spindle? I ask because the .0015 TIR seems a bit excessive... Eh, I'm just curious how it all centers out. Back when I did mine for the 9" I had I set up an extremely tight fitting stepped edge. Oh, and add that thrust bearing, you'll appreciate it a lot.

tmc_31
11-02-2009, 07:33 PM
Thanks Black_moons, I thought the knurl turned out pretty good too. If fact the diamonds were a little sharp so I hit them lightly with a file to save my hands.

Walter, here is the picture of the face that contacts the back of the spindle.

http://i663.photobucket.com/albums/uu351/tmc_31/thecolletcloser020Small.jpg

The OD of the tube is 1.50180, the ID of the spindle is 1.51580 for a difference of about .014. I gather from your question that you are wondering if the tube is torquing the collet over in the nose piece. Could be, I hadn't thought of that since the collet is supported front and back by the nose piece. The nose piece is also supported front and back within the spindle. If you measure the runout right at the collet face (on the workpiece) it is within .0005. So the work is slightly cocked in the collet,or the collet in the nose piece. I just attributed this to crappy cheap Chinese collets. I am going to buy a new Hardinge collet just to see if the runout was improved. It may be that I need to cut a thin bushing out of bronze and loctite it to the drawtube. If you have any other ideas or thoughts, please let me know.

Thanks

Tim

K Barton
11-02-2009, 10:21 PM
Hi all,


Thanks to all who helped with comments, criticisms and advise

Tim

PS,I purchased the 5MT-5C nose piece from the fine folks at grizzly



Just a note the collet set up looks good, one thing to be aware of though is on the spindle nose cam lock holes, if these holes are a blind hole there is no problem, but if when you look in the holes and can see the plate that retains the headstock bearing be very cautious about chips getting into these holes and blocking the oil return passage for spindle bearing as you will then start looseing oil out of the headstock as the oil will be unable to drain back. I encounterd this very problem on a 1340 Cadillic lathe where I work. The solution was to install a blank cam-lock adapter over the top of collet adapter, this will block off the holes and not interferre with normal usage of
collet unit, it also protects the spindle nose from damage.:)

Ken

Walter
11-03-2009, 04:21 AM
http://i663.photobucket.com/albums/uu351/tmc_31/thecolletcloser020Small.jpg

The OD of the tube is 1.50180, the ID of the spindle is 1.51580 for a difference of about .014. I gather from your question that you are wondering if the tube is torquing the collet over in the nose piece. Could be, I hadn't thought of that since the collet is supported front and back by the nose piece. The nose piece is also supported front and back within the spindle. If you measure the runout right at the collet face (on the workpiece) it is within .0005. So the work is slightly cocked in the collet,or the collet in the nose piece. I just attributed this to crappy cheap Chinese collets. I am going to buy a new Hardinge collet just to see if the runout was improved. It may be that I need to cut a thin bushing out of bronze and loctite it to the drawtube. If you have any other ideas or thoughts, please let me know.

Thanks

Tim

Tim,

You confirmed exactly what I was curious about. The Draw bar is most likely ending up cocked. You really need the back end of the draw tube centered in the spindle. a ledge cut on a "washer" or on the face of the thrust washer carriage will solve the problem, clearance of .0015 -.0005 or so between the carriage and draw tube would be acceptable. .014 as it is now will only cause you problems. Granted the tendency of the tube should be to somewhat self center, but it will never be as good as it could be with a properly sized guide / ledge.

--Kurt

tmc_31
11-03-2009, 09:41 AM
Ken,

I looked at those holes last night after reading your post. Sure enough, the camlock holes go all the way through. There was even an aluminum chip lodged in one of them. I don't know if it could migrate to the oil return or not but I will fashion a cover for the camlock face to prevent this problem.

Thanks,

Tim

Your Old Dog
11-03-2009, 11:19 AM
Glad you got the photobucket thing working, those are good pics and interesting. Keep'em coming. Nice job on the closer.