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Edmonton - small part needed for lathe.

I got my first lathe: a colt-720g, took the headstock apart to clean, then realized that the adjustment nut for reassembly is MIA. I'm in a pickle and need someone to machine the nut so I can get back to learning to machine!

There's absolutely no information about these lathes or the original part and its dimensions so I can only provide the thread measurements as I've taken them from the spindle.
-0.966" major thread diameter on the spindle
-18 TPI

I'd like to get something like the part diagram I included. I'm an absolute novice so the dimensions are not set in stone and ideally if someone's willing to help I can meet up and we can confirm the part dimensions with the spindle. I'm just not confident in my novice eye to send this off to be made.

If someone's willing to help then you can inbox me a quote and we can figure it out.

Thanks
 

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How about posting an image or two of your lathe. Never heard of a colt.
It's a "copy" of the Myford Super 7. The main difference is in the headstock which uses opposing tapered roller bearings as opposed to the Myford's combination of brass sleeves and thrust bearings.
What little information on these (basically notifying people they exist) can be found if you look up Myford Lathe Copies. I'd post the link but I have sub-3 posts in my history atm.

15-16 UN 28 maybe?
When I check with a Whitworth gauge, 18 TPI is almost perfect so I don't think 28 will do it.
 

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Crankit

Well-Known Member
It's a "copy" of the Myford Super 7. The main difference is in the headstock which uses opposing tapered roller bearings as opposed to the Myford's combination of brass sleeves and thrust bearings.
What little information on these (basically notifying people they exist) can be found if you look up Myford Lathe Copies. I'd post the link but I have sub-3 posts in my history atm.


When I check with a Whitworth gauge, 18 TPI is almost perfect so I don't think 28 will do it.

Not metric by chance?

Here is a link for Colt Lathes...on a side note, it's a good looking lathe!

http://www.lathes.co.uk/myford-copies/
 

PeterT

Ultra Member
Premium Member
When I check with a Whitworth gauge, 18 TPI is almost perfect so I don't think 28 will do it.

Sorry I grabbed the wrong pitch, 28 vs you said 18. Looking at the common sizes for 15/16 shows 16 or 20 so maybe you have something special.
Not that the pitch would be difficult to make on most common lathes but maybe keep flushing out what it might be.

Even it common Whitworth (that's 55-deg vs 60 right?) I don't see that combo but I'm not that familiar with them
https://www.trfastenings.com/products/knowledgebase/thread-geometry/british-standard-whitworth-bsw


1623133621487.png
 
Sorry I grabbed the wrong pitch, 28 vs you said 18. Looking at the common sizes for 15/16 shows 16 or 20 so maybe you have something special.
Not that the pitch would be difficult to make on most common lathes but maybe keep flushing out what it might be.

Even it common Whitworth (that's 55-deg vs 60 right?) I don't see that combo but I'm not that familiar with them
https://www.trfastenings.com/products/knowledgebase/thread-geometry/british-standard-whitworth-bsw


View attachment 15256
I don't know why I didn't check in both metric and imperial. The thread form is most definitely Whitworth (yes .55*, at least according to my gauge), but the spindle is definitely in mm and the major thread diameter in in mm. See drawing below. This lathe is a tower of babel regarding measurements.
 

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PeterT

Ultra Member
Premium Member
No chance it’s a M24 (0.944”) by module 1.5 (about 17 TPI equivalent)? The wrinkle would still be 55-deg angle because ISO metric typically 60 deg
 
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Here's the spindle threads with 1.5 metric and 18 Whitworth.
 

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