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I got the lathe set up for 16TPI and turned it on to make sure the half nuts worked and everything looked good except for the strange sound every two turns of the chuck. Rather than risk damage to the lathe I aborted thread cutting for today and will be tearing down the lathe to find out where the noise is coming from. I suspect something to do with the motor pulley but I won't know until I dissect it.
Ed
EDIT: Lathe is fixed and cleaned up and ready to go.
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Ah, project creep. Glad I'm not the only one who experiences it.
Lathe (n); a machine tool used in the production of milling machine components.
Milling Machine (n); a machine tool used in the production of lathe components.
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arvidj (07-16-2021)
I started to cut the threads and soon realized they looked like saw tooths. WTF!
I know the gearing is set up right because the scratch pass showed exactly 16TPI. I repeated the attempt on some delrin I had and same problem. Had to be the angle I set the compound to. I had set it to 29.5 degrees but to the incorrect reference. I got bit by this same error when I first turned threads on my 14x40 lathe. Corrected the angle, still 29.5 degrees, and tried cutting on the delrin and perfect threads.
Since I butchered the original part I have to make a new blank and start over.
Ed
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EdK (07-17-2021)
(07-16-2021, 08:30 PM)EdK Wrote: I had set it to 29.5 degrees but to the incorrect reference. I got bit by this same error when I first turned threads on my 14x40 lathe.
Ed
I ended up putting a new punch mark on my compound 90° away from the factory line to become the 'correct' zero point.
Willie
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Highpower (07-17-2021), arvidj (07-17-2021)
(07-17-2021, 02:38 AM)Highpower Wrote: (07-16-2021, 08:30 PM)EdK Wrote: I had set it to 29.5 degrees but to the incorrect reference. I got bit by this same error when I first turned threads on my 14x40 lathe.
Ed
I ended up putting a new punch mark on my compound 90° away from the factory line to become the 'correct' zero point.
I'm going to fine tune the angle and scribe a line on the cross slide to mark the proper angle. I did the same thing on my 14x40 lathe but being an old fart, I totally forgot about my past errors.
Ed
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EdK (07-17-2021)
I blame the South Bend book "How to run a lathe". All of my threading woes (sawtooth, double start) in the beginning resulted from following that book to the letter. There are no footnotes in there telling you that the compound angle and the threading dial chart didn't work for Asian lathes. But everyone said that was THE book to follow.
Did they even make Asian lathes back then?
Willie
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Highpower (07-19-2021), arvidj (07-20-2021)
Got'r done yesterday evening. No mishaps except a 3/8" metal sliver across the end of my thumb.
Ed
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Where are the jaws?
Full of ideas, but slow to produce parts
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f350ca (07-19-2021)
(07-19-2021, 11:09 AM)rleete Wrote: Where are the jaws?
I took them off while I made the adapter. Made it easier to test the threads I was cutting against the puller piece.
Ed