Lathe Hack and old school tool use.

[Worth1]

Originally Posted by loulac

Don't you think you are a bit overdoing it ? This must be your Texan touch. The point is I have been young much longer than you have.

I read your post at 10 o'clock French time, you wrote it at 3 a.m. Texan Time. Do you ever sleep ?

Normally Texans dont say what they dont think at least they used to.
Here is an explanation of the 2 TPI idea.
I want to cut french checkering in steel or something close to it.

It would take some time but it can be done.
You cut one whole thread it doesn't have to be to full depth
Then you evenly mark out lines around the work starting at the first thread without removing the work.
Remove work rotate to next mark and cut threads keep doing this for all of the threads repeat cutting the left hand threads.
If you skip a given amount of those indexed marks going both ways you will end up with diamonds in the pattern.
Say cut 5 threads skip 3 marks cut 5 threads., what ever the count would need to be to end up right at the end.
To get the amount of line spacing you would use the same formula you would use for cutting gears.
This is the same process used to cut multiple start threads.

Worth.