Thread cutting on the lathe ??

[jack620]

At times when using HSS I will chamfer with the threading tool,...

OK thanks. I had another look at the notes I linked to and that's what he recommends too.

[welder]

Thank you all for your help support and positive comments. I think I can screwcut now I just cut a 5/8 and 1/2 thread on both the nut fitted and the thread looked good now for internal threading

[welder]

I was making a plug gauge for the lathe last night and. It was going swimmingly until I stalled the lathe which moved the part in the chuck. I malsomoved the tool how do I bring the tool back to the same position on the threads?

[Bryan]

By juggling the compound and cross slide. What's more concerning is that the work may be knocked out of true. If it's wobbling it may be better to start again. You must have gone pretty hard to stall it. You need lighter cuts as you get deeper because the cut gets wider. Even on my 14" lathe I'll only take a thou on the last few cuts.

[Anorak Bob]

I was making a plug gauge for the lathe last night and. It was going swimmingly until I stalled the lathe which moved the part in the chuck. I malsomoved the tool how do I bring the tool back to the same position on the threads?

Very carefully Andre.

A jeweller's loupe helps. Withdraw the tool so that the tip of the tool is just outside of the cut thread. Rotate the spindle by hand with the lead screw engaged and carefully follow the progress of the tool. Use the compound to advance or retract the tool to synchronise with the thread pitch. Then infeed using both the compound slide and the cross slide. You can manage to realign the tool with the thread if you take it easy. I have had the same thing happen to me on a number of occasions. I cut threads with the compound set at zero.

I'm sure others will pipe up with better ways of achieving realignment but slow and careful has worked for me.

Bob.

ps. Bryan beat me to it. Same technique. A job out of whack in the chuck complicates things. Too complicated and it heads for the bin.

[wbleeker]

By juggling the compound and cross slide. What's more concerning is that the work may be knocked out of true. If it's wobbling it may be better to start again. You must have gone pretty hard to stall it. You need lighter cuts as you get deeper because the cut gets wider. Even on my 14" lathe I'll only take a thou on the last few cuts.

+1 But a bit more detail Andre, check to see if your job is still true in the chuck, if not and there is a surface you can use to indicate off, reset it. Then with the job true, engage the leadscrew, and rotate the chuck by hand towards you to take up any backlash in the geartrain/leadscrew etc, then you can use compound and crosslide to pick up the thread. I do this with the machine running on long threads but with a short one as I presume you have it is safer to follow the steps above.
Will

[pipeclay]

Did you by some chance advance the tool at the end of the thread rather than retracting or did you forget where you were upto with the compound.