Problem with lathe chuck

J

JLCues

AzB Silver Member
Silver Member
I'll try to keep this short. I have an Enco 13x40. About a year ago I bought a Bison six jaw set tru. The first one I got, as soon as I got it, I put the key in the chuck and almost had to use two hands to open or close it. Never even got to install it. I called Enco and told them, they sent me another. It was fine. I installed it according to the directions (I have absolutely no machining experience by the way). I indicated the spindle face. The .001 indicator didn't even hiccup. I installed the back plate. It indicated almost as well as the spindle face. Put on the chuck, spent about 45 min of adjusting the chuck to indicate 0, I was using a drill blank to indicate on. The chuck is supposed to have a repeatability of like .0004. I don't have the paper work in front of me but it's something like that. I loosened the chuck and re-tighted. It went from 0 to about .003. I readjusted to get it to 0 again. Loosened and re-tighted off .003 again. Called and told Enco it wouldn't repeat. They sent me another, it sat on the work bench for about 6 or 7 months because I was fed up with it at that point. The other day I took a stab at it again. The spindle face indicated the same as before. The back plate indicated around .002. I took it off and rotated it. Same .002. Took it off again and triple checked that there was no debris. Re installed it. Same .002. What am I doing wrong? When the second chuck was sent back, the back plate went back as well. So this is a different back plate than the one I got to indicate 0. I am at a complete loss. Any suggestions? The factory three jaw, 8 out of 10 times will indicate around .001. Is going through all this even worth it? I apparently thought so at one time but this is becoming a real pain in the azz trying to get rid of .001 of runout. It's very close to getting boxed up and put on ebay.

Jason
 
Are you tightening the chuck at the same socket each time? I was taught that when tightening a scroll chuck to always tighten at the O mark . It's a long shot but might be worth trying.
 
Canadian cue said:
Are you tightening the chuck at the same socket each time? I was taught that when tightening a scroll chuck to always tighten at the O mark . It's a long shot but might be worth trying.
Click to expand...
This is a very valid question....

1st) Bison recommends that the backplate might need or should be machined...your first one was the keeper!

2nd) I have heard that depending on where items are made (Chinese lathes) for example....the highest quality goes to the highest bidders..next best quality to the next highest bidder and so forth.

In this case, Enco is a sister co. to MSC. The Bison chuck you received may be a lesser quality, believe it or not, and that could be why you are saving $$$ and having problems. ??? Ask them to verify...if they will?

Hope this sheds some light...best price is not always same quality even though it has the same name!!

All IMO of course!

Chris
 
Jason, You said you have an Enco Lathe so I will assume that you have a d1-4 spindle mount. Is the problem after you loosen the scroll on the chuck or are you loosening the nuts on the backplate? I have the same chuck with a d1-4 backplate and have not had any problems. I have found that if you remove the chuck from the spindle that you have to re inidicate when you lock down the cams on the spindle or you can get some runout.
also make sure that the "set-tru" screws are firmly against the backplate when you tighten the nuts that hold the Chuck to the Backplate. hope this helps, Jim
 
Canadian cue said:
Are you tightening the chuck at the same socket each time? I was taught that when tightening a scroll chuck to always tighten at the O mark . It's a long shot but might be worth trying.
Click to expand...

Actually gave all three a twist.
 
Poulos Cues said:
This is a very valid question....

1st) Bison recommends that the backplate might need or should be machined...your first one was the keeper!

2nd) I have heard that depending on where items are made (Chinese lathes) for example....the highest quality goes to the highest bidders..next best quality to the next highest bidder and so forth.

In this case, Enco is a sister co. to MSC. The Bison chuck you received may be a lesser quality, believe it or not, and that could be why you are saving $$$ and having problems. ??? Ask them to verify...if they will?

I actually got my third chuck straight from Tool Mex, which from what I understand supplies all who sell Bison products. As far as making a face pass on the back plate, they told me NOT to, that it isn't nessary. I'm sure it's just operator error.

Jason
Click to expand...
 
Tooljunkie said:
Jason, You said you have an Enco Lathe so I will assume that you have a d1-4 spindle mount. Is the problem after you loosen the scroll on the chuck or are you loosening the nuts on the backplate? I have the same chuck with a d1-4 backplate and have not had any problems. I have found that if you remove the chuck from the spindle that you have to re inidicate when you lock down the cams on the spindle or you can get some runout.
also make sure that the "set-tru" screws are firmly against the backplate when you tighten the nuts that hold the Chuck to the Backplate. hope this helps, Jim
Click to expand...

It does have the D1-4 mount. Problem was just from loosening the scroll.

Jason
 
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