Collet chuck use

[mmcmdl]

I forgot to mention that my collet chuck has 3 tenths runout.

Better get that fixed Dave

 

[Shootymacshootface]

NASA asked me to make a one-off part


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Yeah, they have been knocking my door down too.

 

[erikmannie]

It seems to me that you could make that collar in either a 5C collet, 3 or 4J chuck.

I have done those in a 3 and 4J, & they did not turn out well if I flipped them around (I couldn’t get the faces coplanar).

I read that you only need to grip 1/32” in a 5C collet chuck. That sounds like a small amount to me!

 

[mmcmdl]

NASA asked me to make a one-off part

Yeah, they have been knocking my door down too.

They turned me down . I think they heard I used my old dial calipers for scribing .

 

[Braeden P]

3 tenths! you need a hardinge lathe now!

 

[NC Rick]

Semi related to your question Dave is that i replaced the old 3 jaw chuck on my lathe and have been really surprised by the improvement. It has reduced the need to switch to my collet holder by a lot. For a simple bushing i no longer need to make the swap. Previously i was swapping many times per week. In either the three jaw or collet using a stop really helps. Otherwise i face both sides, measure the length (in the collet this means removing smaller parts to measure) then rig a dial-indicator before touching off and removing the right amount. When things are going right and the guys at NASA are to busy messing with O-rings to check i can get away with parting to length.
in reality little bushings like that are not as easy as it seems they should be.