How to find the center of a pc of all thread

[Paul Waddle]

I wish to use a pc of 1" 8tpi all thread to make an auxillary shaft for my wood lathe chuck. I wish to use a length of 3/4" crs for the main shaft,2" of all thread. Previous attempts have resulted in in .025. run out when chuck was installed..The length of shaft is 10". I THINK my problem is not being able to accurately locate the exact center of the all thread. I want to bore the all thread for 1/2" hole,turn the 3/4" shaft to 1/2" x1", and J B weld it in the all thread. I want to keep the run out to .003 or less. I have access to a metal lathe,a 4 jaw chuck ,and face plate and lathe dogs. Will someone give me the correct porcedure? Thks,pw:confused:

[Chris Padilla]

Paul,

Seems to me you have the perfect equipment to drill in the dead center of the all thread with your metal lathe. I mean, how does the all thread look while spinning in the metal lathe?

[Daniel Winsor]

I don't have a metal lathe, just a wood lathe, but that just makes it easier for you. What I would do is to chuck up a waste scrap of hardwood and turn it round. Then use the jacobs chuck in the tailstock to drill a hole in the wood. Tap the hole for 1"x8tpi and screw the all-thread in. You could use a nut and washer on the all thread to index against the wood so it runs true. Once you get the all-thread running true, use the jacobs chuck to drill your hole.

Dan

[Bruce Page]

It’s tough to do with all thread. You could try tightening two nuts against each other and then chucking on one of the nuts. It might work, might not. If you have access to a metal lathe you’d be better off making it as one piece and chasing the 1”-8 thread.