Getting steady rest / 3 jaw bearing chuck aligned and centered

This has been a good thread with lots of thoughtful insights from all the contributors - thanks for that. One aspect that hasn't been touched on is the repeatability/accuracy of scroll chucks. RidgeRaider has one on his headstock and one in the steady rest. Scroll chucks do not have great repeatability. Simply opening and closing the chuck on the bar can result in a .002"-.003" discrepancy. This difference can be rectified by tapping (not smashing) the jaw on the high side with a small brass or wood hammer. Using this technique, you can achieve a more consistent result when chucking your work. RidgeRaider, maybe you knew this and already incorporated it into your routine, but I hadn't seen it mentioned by anyone.
My 2 cents,
Gary
 
This has been a good thread with lots of thoughtful insights from all the contributors - thanks for that. One aspect that hasn't been touched on is the repeatability/accuracy of scroll chucks. RidgeRaider has one on his headstock and one in the steady rest. Scroll chucks do not have great repeatability. Simply opening and closing the chuck on the bar can result in a .002"-.003" discrepancy. This difference can be rectified by tapping (not smashing) the jaw on the high side with a small brass or wood hammer. Using this technique, you can achieve a more consistent result when chucking your work. RidgeRaider, maybe you knew this and already incorporated it into your routine, but I hadn't seen it mentioned by anyone.
My 2 cents,
Gary
My headstock has an independent 4 jaw. So I can dial it in on that end at least.
 
My headstock has an independent 4 jaw. So I can dial it in on that end at least.
One note of caution when using a 4 jaw for cue work. You have to be quite careful with how much torque you put on the individual jaws. Even with plastic collets it's easy to dent a cue. So when dialing in your part loosen the opposing jaw before tightening the other. These things may seem obvious but it never hurts to mention it.
 
One note of caution when using a 4 jaw for cue work. You have to be quite careful with how much torque you put on the individual jaws. Even with plastic collets it's easy to dent a cue. So when dialing in your part loosen the opposing jaw before tightening the other. These things may seem obvious but it never hurts to mention it.
Absolutely. I toasted a few maple shafts when I first started.

I beat the stupid out of myself, and now I dial it in with care and a good leather collet.


Minor dents are easy enough to get out with a glass vial though.
 
My 4 jaw chuck I never use for cue making, too much clamping pressure.
6 jaw chucks get a lot of hate from machinists, but I find them super usefull, especially when it has a set-tru feature, essentially letting you dial in zero, like you would on a 4 jaw.
Collet chucks are amazing, safer to use, super accurate and so much faster if you have to do repeat operations. I have a ER40, A 5C and a Pratt Burnerd KC15 that takes stock up to 1.5"
 
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Y'know, my lack of knowledge is going to show my ass a lot on most of this stuff. So bare with me please haha.

I have no true idea if the piece I had in there was true. I like to think it was, because I turned it in the lathe and it was zeroed, but I guess that doesn't mean much in the scheme of it all.

So, knowing that already in the back of my head, I found a test bar that has a long enough parallel section in it that I could use. After cue-mans advice to bore the jaws, I did and after an hour or so of doing that and re-checking and re-boring, I finally got it to about 2.5 thousands on the 3jaw. That's a lot better than it was, that's for sure. I'd love to get it down to 1thou, but I am unsure if that's a pipe dream for this 3jaw.

The only problem I see with this set up is you are only holding one bearing with the steady rest. So unless you find a way like a metal shim or something to make it hold both bearings it may never give you the very best accuracy possible.
 
The only problem I see with this set up is you are only holding one bearing with the steady rest. So unless you find a way like a metal shim or something to make it hold both bearings it may never give you the very best accuracy possible.
Hmmm. I’ll have to figure something out for that.

Assuming I’d never be able to just sleeve it with a pipe over both the bearings and have that pipe contact the posts in the lathe steady? Accuracy would be sloppy I assume.
 
Hmmm. I’ll have to figure something out for that.

Assuming I’d never be able to just sleeve it with a pipe over both the bearings and have that pipe contact the posts in the lathe steady? Accuracy would be sloppy I assume.
It may not make a difference, but a single bearing has a little pivot to it on the inner race. The fact the rear bearing is up against the front bearing may be enough to stop the pivot. But having pressure on the outside of both bearings would be best. Brass posts shaped like an L would do it. Or a small shim the length of the two bearings. I think trying to bore a cylinder to go around it might be overkill although it was a good idea on your part.
 
Some times simple is better. This is a setup I use for taper boring forearms after I core a cue. Just a simple delrin collet inside a bearing.
 

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Some times simple is better. This is a setup I use for taper boring forearms after I core a cue. Just a simple delrin collet inside a bearing.
What bearing is that?

And what’s your method for getting the bearing and steady rest dead center with the headstock?

I’m still trying to find time to give ya a call. Hard to even find a few mins on a weekday.
 
What bearing is that?

And what’s your method for getting the bearing and steady rest dead center with the headstock?

I’m still trying to find time to give ya a call. Hard to even find a few mins on a weekday.
You have to get the part running in the same axis as the spindle. So the way I do it is I support my part with the tailstock then carefully adjust the jaws of my steady until they touch the bearing. You have to be careful not to pull the part off axis. Your dial indicator won't tell you that. I use standard bearings, a 6207 works well for larger diameters. If you leave your bearing setup in the steady, you just need to press in different collets. If I pull my bearing out I usually just loosen the top jaw of the steady as to not disturb the location of my bearing. if I get a minute I could make a vid of the process, not hard just have to be delicate while centering your bearing in the steady.
 
You have to get the part running in the same axis as the spindle. So the way I do it is I support my part with the tailstock then carefully adjust the jaws of my steady until they touch the bearing. You have to be careful not to pull the part off axis. Your dial indicator won't tell you that. I use standard bearings, a 6207 works well for larger diameters. If you leave your bearing setup in the steady, you just need to press in different collets. If I pull my bearing out I usually just loosen the top jaw of the steady as to not disturb the location of my bearing. if I get a minute I could make a vid of the process, not hard just have to be delicate while centering your bearing in the steady.
Seems like simple is better. I was trying all sorts of jacked up ways before.

My problem with the 3 jaw and 2 bearings is it's heavy. It's drooping most stock I put in. I'd love a video of what ya do!
 
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