How to use thread dial with no chart?(on a sheldon)

[D.sebens]

I don’t have any need currently to thread but I haven’t threaded with this lathe. It’s an early Sheldon 10”. The thread dial is 1-4 if I remember correctly. I don’t think I saw any chart on the machine for when to engage for selected tpi’s. Any tips on how to figure that out?

 

[OTmachine]

Please Explain How A Threading Dial Works.

I've been watching some videos on threading. I saw a guy make a cut then move the carriage back set the depth of the next cut and wait for the threading dial to hit 1 and then engaged the half nuts. He did it every pass. I don't see how that guarantees the cutter will cut in the same thread as...

www.hobby-machinist.com

 

[woodchucker]

you won't find a chart.
its a general rule. for even threads, you can engage on any mark.
for odd, I think it's any number.

 

[D.sebens]

Any mark as in any number or division line?

I actually have the Sheldon operation manual/book. I hadn’t read it all the way through. The link ot machine posted references that book. That being said, if I picked single number when starting the thread would could I choose that same number every pass for any thread? Or could it end out out of sync for the weird threads that have weird numbers to engage on?

 

[woodchucker]

Any mark as in any number or division line?

I actually have the Sheldon operation manual/book. I hadn’t read it all the way through. The link ot machine posted references that book. That being said, if I picked single number when starting the thread would could I choose that same number every pass for any thread? Or could it end out out of sync for the weird threads that have weird numbers to engage on?

it should be any division for even.
Any number for odd.
But if the manual says different, I am not going to argue.

When unsure, just pick the same number, you can't go wrong that way.
For metric, things are different.

 

[D.sebens]

it should be any division for even.
Any number for odd.
But if the manual says different, I am not going to argue.

When unsure, just pick the same number, you can't go wrong that way.
For metric, things are different.

I don’t yet have the transposing gears so metric isn’t possible for me yet.

 

[Jim F]

Leave the half-nuts engaged, reverse the motor to return to starting point.
Guys at work do it that way.

 

[talvare]

I believe Woodchucker is correct. But, it's not too difficult to figure out. Chuck up a piece of 1/2" PVC pipe and start making some test passes. You'll figure it out pretty quickly.
Ted

 

[Nutfarmer]

If in doubt engage the half nuts at the same place on the dial each time. If threading metric keep the half nut engaged.

 

[SLK001]

It depends a lot on your leadscrew TPI. For a SB10, we use this:



Here's a better .pdf version of the same: