Question About Antique Threads

RHayes

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This is a mandrel from a vintage spinning wheel. I have replicated a number of these using taps and dies but would like to actually know how the originals were done. My guess is on a manual lathe of some sort as it appears the cutting action on this left hand thread starts from a dead stop.

Any ideas or thoughts?

IMG_1845.jpg
 
The abrupt stop on that thread leads me to believe it was milled.
 
The thread was made with a file to lines drawn on the shaft.
The Standard Thread Pitches did not come along until J and W Wyatt patented such a system in 1760
 
There is also a square nut with matching threads. So would a tap be made with the file as well?
The shaft is scratched with the pitch in places. I could take another photo but some of the marking is visible at the bottom right. It didn't match anything metric or inch system but close to 18 threads per inch. So possibly a lathe was used but not with full thread cutting ability, lead screw, change gears ??

I
 
When I visited some factories in India in the 70s making single cylinder engines,the long studs had threads cut freehand with a single point tool ,.then cleaned up and sized with a hand held chaser until a nut fitted...All done in a simple home made lathe .....the bearing journals on the forged crank were turned in an ancient english lathe,without any power feed or leadscrew.
 
This wont help answer the OPs questions and what I think I am seeing may only be an optical illusion but are the threads not even side to side so that the left side of the thread is a steeper angle than the right side?
 
Given the abrupt end to the thread, I would guess that the thread was single point cut. Here is a a process of cutting threads without the benefit of a lathe.
https://ibuildit.ca/projects/cutting-wooden-threads/
The same process could be used with a steel shaft by advancing the depth of cut with multiple passes. This could result in the square end of cut shown above.
 
When my dad started in as a kid during the depression working on his stepfathers gold crusher making studs and bolts was a majority of the work. His first lathe did not have change gears but used a crank on the end of the lead screw. To cut threads they would use a template like a screw pitch gauge and hold it to the work then crank the handle to match the gauge as the stock rotated. Crude but it was all they had.
 
I took another photo of the other side showing the interesting scratch pattern that seems to relate to the threads, but have seen others that had the short section of left hand threads but no scratch pattern like this one. The single scratch to the left of the threads appears to be a measurement reference that relates to how far the wooden pulley(called a whorl) threads on to the shaft. You can just barely see the square nut that is embedded in the wood. The smooth area to the left of the thread and the single scratch mark is wear from the wood bobbin(not shown). I'm guessing late 1800's. Thanks for all the suggestions.
IMG_1846.jpg
 
Can you get a close up of the end of the thread with the flash turned on?
 
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