South Bend Quick Change Collet chuck from Grizzly

[weldnfab]

Hi everyone, I just ran up to Grizzly in Bellingham today and picked up a South Bend R-8, Quick Change Collet chuck set, for my Bridgeport clone milling machine, thinking that it will sure make my life a lot easier when needing to change between tooling in the mill. I don’t have any experience with these collets, and am finding that when I install an end mill or drill bit in the collet, ( let say 3/8” drill bit in the 3/8” collet ), once it is tightened and I am done using it, I thought it would be real easy to unscrew the nut and remove the collet and quick change to another size for the next operation. Not !!!!! Once the nut has been removed, I can’t get the collets out of the main body very easily. I am having to use a pc of aluminum rod and drive them out of the main body, or unscrew the drawbar. (The whole idea is to not have to remove the drawbar everytime i need to change tools.) I can drive them out by catching the lip on the collet and carefully driving it back out. This doesn’t seem right though . Can anyone tell me what I am doing wrong, or is there a tool like a wedge or something, that you are suppose to use to wedge the collets off when changing them to another collet. The set sure looks nice but isn’t doing what I thought it was supposto to so.. Thanks a lot.!!

http://www.grizzly.com/products/16-Piece-Quick-Change-Collet-Set-R8/SB1349

[adatesman]

Looks like the collets have a groove in them for extraction like ER collets, so perhaps you need to snap the collet into the nut before putting tooling in (like with ER collets)?

[Toolguy]

Collet Holder

You are supposed to put the collet in the nut first, then insert the tool into the collet, then tighten. When you unscrew the nut it will break the collet loose and come out with the nut.

[adatesman]

Btw, they look a lot like TG collets. Anyone know if that's the case?

[weldnfab]

thanks

thanks everyone I will try this first thing in the morning
now it all makes sense the groove in the collet should engage into the threaded nut , before I install any tooling. I was putting the collet with tooling into the main shank, then spun the nut on, it milled ok, but sure made the collet hard to remove when done. Thanks again, can't wait till tomorrow. ;-)

[macona]

Btw, they look a lot like TG collets. Anyone know if that's the case?

No, they are not TG. Looks like a custom design.

[weldnfab]

Thanks

Well you guys were right. Thanks a million. I took one of the collets and it does snap right into the coller. Then the rest of the process works flawlessly. Really appreciate the input. I love this new set from Grizzly!

[Rich Carlstedt]

Do yourself a favor
Using collets for endmills is not a good idea when heavy cuts are made, as the helix angle on the cutter will pull the endmill out.
If your depth of cut is critical, you will loose the part, and not even realize it .

To help guard against this, put a dot of red nail polish ( quick dry laquer) on the joint between the cutter and the collet.
"If" the cutter pulls, the dot will break and will be visible even at 2,000 RPM
when you look at the joint.
When removing the cutter, just clean with a bit of laquer thinner.

Rich

PS
Collets specifically made for endmill use have a plug that locks into the Cutter Flat to prevent pulling.
Most inexpensive collets do not employ this feature

[Toolguy]

Collet Holder

Agreed - For heavy cuts use a setscrew endmill holder.
I have 4 sets of the holders the OP has. (I think they are the same.) Although it's a proprietary collet, I have used them for years with good results on normal to light cuts.

[Jaakko Fagerlund]

Guys, tighten your clean collets if you are experiencing a pull-out under a cut. What I've seen is that the endmills will break first before coming off the holder.

If a small screw or two supposedly prevents this, then the collet should grip even with more power, if it is clean and without dings.