Threading intimidation.

Tb1988 said:
Gotcha. Thanks for your help. Well atleast I know what lathe I have now
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Well, that'll be a heckuva start. I'm glad i kinda half way maybe sorta thought that maybe I oughtta check to be sure I hadn't heard of an 81 tooth gear... I'm working on finding the directions for that, which I "might" have, but I'm not sure. I suspect you already have what you need there to make threads, but I gotta find a reference, as min has a "oh so similar" but still different gear train. I don't want to send you the wrong way...
 
I think I do have what I need to be able to thread. I’m going to try it this evening and see what happens. I appreciate the information. I’m glad to know what I’ve got.
 
It’s been mentioned before, but I would not only scribe your thread pitch on a piece of scrap,I would make a complete thread (either internal or external) to verify it will match the mating internal or external thread.

Many moons ago (1999) when I got my Seneca Falls machine I needed to modify a number of chucks to fit the spindle. The spindle is 1 7/16-12. I picked the change gears and installed them.

Before threading the internal threads on one of the chucks I decided to make a plug with mating external threads to use as a go/no go gauge on the chuck threads. When I finished the (Delrin) plug I tried it in the original chuck.

For the life of me no matter what I tried it wouldn’t fit. When I got out the thread gauge I realized I’d made an 11 1/2 pitch thread rather than a 12 pitch thread. I had misread one of the numbers on the change gears.

I changed out the errant gear and made a new plug. It fit like a glove. I had no idea where an 11 1/2 pitch thread was used until a few years later when I needed to make some adaptors for a lawn sprinkler. As it turned out 11 1/2 tpi is for a standard garden hose.
 
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projectnut said:
It’s been mentioned before, but I would not only scribe your thread pitch on a piece of scrap,I would make a complete thread (either internal or external) to verify it will match the mating internal or external thread.

Many moons ago (1999) when I got my Seneca Falls machine I needed to modify a number of chucks to fit the spindle. The spindle is 1 7/16-12. I picked the change gears and installed them.

Before threading the internal threads on one of the chucks I decided to make a plug with mating external threads to use as a go/no gauge on the chuck threads. When I finished the (Delrin) plug I tried it in the original chuck.

For the life of me no matter what I tried it wouldn’t fit. When I got out the thread gauge I realized I’d made an 11 1/2 pitch thread rather than a 12 pitch thread. I had misread one of the numbers on the change gears.

I changed out the errant gear and made a new plug. It fit like a glove. I had no idea where an 11 1/2 pitch thread was used until a few years later when I needed to make some adaptors for a lawn sprinkler. As it turned out 11 1/2 tpi is for a standard gardener hose.
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Interesting. Thanks for the tip!
 
by the way, there should also be a serial number stamped into on top the bed at the tailstock end

1735765867868.png
discussed here:
https://www.wswells.com/sn/sn_index.html

Take that number and try a look-up here:
https://www.wswells.com/sn/sn_db.html

That will help establish the year it was built.
I have a CD of old Southbend info that with year and catalog number (22-YB) I can try to find the original catalog pages for it.

Brian
 
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