single point single start threading ?

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InvisibleMan

Member
Joined
Feb 13, 2011
Messages
716
Location
San Jose, CA
I have a question about setting up the compound slide for single point, single lead threading - specifically internal threading. I'm using the LMS 8.5x16, otherwise known as the Sieg C4.

From all I've learned from youtube videos, etc., for the external threads, the compound slide is deflected 29.5*, such that the crank handle is offset to the right of the cross slide crank handle (probably bad terminology:)). So, I would loosen the compound, turn it clockwise to 29.5*. No problem there.

However, for internal threading, the compound slide crank is always shown offset to the left of the cross slide crank handle. Mine doesn't go there. It won't swing that far. Do I instead turn the compound counter clockwise to 29.5* on the other side of the dial, and have the crank on the back of the lathe?

I hope that makes some sense:redface: Resin is soft enough I may not need the offset anyway, but I'd like to know. I've got multi-lead threads working great with no offset.
 

InvisibleMan

Member
Joined
Feb 13, 2011
Messages
716
Location
San Jose, CA
OK, mystery solved! Shawn emailed (thanks, Shawn!), confirming what I ~thought~ was the right answer, but my lathe just wouldn't do it. Then, I found a "supplementary" users guide via google search, and it had a couple of modifications to make to my lathe. Modifications made, problems solved.

So, if you have this lathe, go here: http://www.fenichel.net/papers/Bob Ackert's SIEG SC4 Manual.pdf and improve your life:biggrin:
 
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