# High Speed Threading (to a shoulder) On A Manual Lathe



## RobinHood (Feb 7, 2020)

1000 rpm, 1.0 mm thread pitch, to a hard shoulder and not crash the tool.... all on a manual lathe.

Came across this video by a British Machinist.






I think I just added another project to my already long list.


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## PeterT (Feb 7, 2020)

Good score Rudy. That is a very neat design. He is right, there are other retracting mechanisms, but none that I've seen with that amount of retraction reach to clear shoulders like his demo video + simplicity of resetting tool position. I don't 100% understand the interaction geometry of the parts. Reminds me of a Winchester lever loader which I don't fully understand either LOL. Maybe I could reach out to him & even get some sketches, from that load into my CAD program & do the similar motion evaluation.

I scratched my head over this thread retraction issue in the past & never really resolved, leaving it to: 
1. run threading tool in opposite direction (from HS to TS). Not all lathes have the Fwd/Rev & feed screw direction capability and/or screw spindle vs Camlock. Fortunately mine does.
2. have the retraction occur with solenoid, either directly to the plunger movement itself, or un-triggering a lock & allowing a spring to move. (I think that's mechanically what he achieved).
3. installing a mini dedicated geared motor on the end of the lathe spindle that basically drives the threading operation. The main motor is turned off & is just rotating along for the ride. A glorified way of powering the 'hand crank' method but now you have some power behind it & potential to limit stop electrically

2&3 are above my electrical pay grade so they sit in cobweb mode.

I'm game to work on this if you are!!


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## RobinHood (Feb 7, 2020)

Peter, I stumbled upon his videos as I was researching info on my Clarkson T&CG; found this website: http://bedroom-workshop.com. There was a link to Paul Hopewell’s videos. He has a Clarkson as well, but some parts were missing - so he made them.

I agree with you that threading from H to T solves a lot of the crash potentials. I use it whenever I can. Like you, I was very intrigued by his clever design.

If you can get some further info (plans), I would be up to pursuing the project.


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## Perry (Feb 7, 2020)

"pucker factor increases to involuntary bowel movement"    

He has a way with words.    lol.


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