Seneca Lathe

Ah. Thanks very much.

If anyone has a use for them, they can have them for the cost of shipping. A small flat rate box would probably do it.
 
My SF lathe has a couple of keyed spacers which fit over the change-gear shafts to allow for aligning the gears, they're the same width as a gear. Typically one with the spindle gear and one on the leadscrew gear, one inside of the gear and the other the outside.

Here's an example of one on the inside of the spindle gear keeping it lined up with the ouside of the ganged idler gears and a matching spacer on the outisde of the leadscrew gear keeping it meshed with the inside ganged idler. Not sure if any of those are the same or not.
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Progress report:

After a couple of hints from @derf I found solutions to both the compound angle lock and the compound lead screw nut.

The compound lock was a case of a broken off set screw jamming up the threads. I thought that was where it would be but couldn't get it to work. Chased it with a bottoming tap to get the broken bits out of the threads and all is well.

The lead screw nut for the compound I had to fabricate, but it also went right where I thought it must. Conveniently enough, the lead screw is a common 7/16-14 thread so I was able to TIG a post to an ordinary hex nut and fix that issue as well.

Now all I need to do is get the 3 jaw chuck tuned up a little better and learn to grind HSS tools (I have printed out @mikey 's excellent instructions) and I should be able to start making chips.
 
Progress report:

After a couple of hints from @derf I found solutions to both the compound angle lock and the compound lead screw nut.

The compound lock was a case of a broken off set screw jamming up the threads. I thought that was where it would be but couldn't get it to work. Chased it with a bottoming tap to get the broken bits out of the threads and all is well.

The lead screw nut for the compound I had to fabricate, but it also went right where I thought it must. Conveniently enough, the lead screw is a common 7/16-14 thread so I was able to TIG a post to an ordinary hex nut and fix that issue as well.

Now all I need to do is get the 3 jaw chuck tuned up a little better and learn to grind HSS tools (I have printed out @mikey 's excellent instructions) and I should be able to start making chips.

I'm thinking somewhere along the line someone replaced the original compound lead screw. First off I've never heard of a 7/16-14 thread on a lead screw. That would make each full revolution of the handle advance the cutting tool about .071". The factory standard compound lead screws are generally 8 or 10 threads per inch. An 8 pitch would advance the cutting tool .125" while the 10 pitch would advance it .100" per revolution.

The compound lead screw on my Star #20 was originally 7/16-10. When it wore out I replaced both the screw and nut with a 3/8-10 (7/16-10 was unobtanium) to keep the graduation dial on the compound accurate. In this case the Star was the only lathe I had at the time. I would have turned a new lead screw 7/16-10 if the lathe was working. Instead I had to order a screw and nut from McMaster. I modified the nut to fit on the mill and adapted the new smaller lead screw to the original handle.
 
Interesting as the cross slide on my SF is a 7/16-8. I'm pretty certain it's the correct and probably original screw, as one full rotation moves the compound in 1/8", which seems an odd fit until you look at the graduations on the dial being 1-250, meaning each tick is 0.0005"
(1/8 = 0.125, 0.125/250 = 0.0005)

Seems they had some variation in the design of these.
 
Anyone have a source for the full dimensions of the Seneca 3s or #3 collets? I know the back bearing is 1.000" and length is 4.59". Ultimately I am looking for the angle of the head but if I can find the width of the head and the length of the head I can figure it out with good old geometry. I have searched the interwebs but can't find it. Thanks.
 
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I too thought is was odd that the screw was a 14 pitch, but it didn't have a dial either. That comes out to .0714285 per rev. When I made the dial, I cut 72 graduations and called it close enough.
 
Anyone have a source for the full dimensions of the Seneca 3s or #3 collets? I know the back bearing is 1.000" and length is 4.59". Ultimately I am looking for the angle of the head but if I can find the width of the head and the length of the head I can figure it out with good old geometry. I have searched the interwebs but can't find it. Thanks.

The 10th and 13th edition of the Machinery's Handbook have a section on collets. The complete dimensions for both the Seneca #3 and #3s are included. Some other editions may include this information. They are no longer included the 16th edition.
 
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cp1.jpg


No dial on mine either. Must have been the economy model...
 
The 10th and 13th edition of the Machinery's Handbook have a section on collets. The complete dimensions for both the Seneca #3 and #3s are included. Some other editions may include this information. They are no longer included the 16th edition.

If you have one could you send me the dimensions? Or is there a source to view online? I couldn't find anything available here or elsewhere.
 
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