Thats a handy trick to remember Bill.
It immediatey sparked my curiosity about how would I go about finding other prime numbers above 3 without an indexer on any typical bench lathe.
Numbers like 5, 7, 9 or even 13 might be challenging
Say we want 5 divisions
Set the lathe to the coursest pitch thread -(lets make it 1-3/4"UNC)= 5 tpi on my charts
Calculate
1000/
(tpi x Divs) =
1000/
(5 x 5) = 40
When a micrometer or dial indicator shows the carrage has moved 40 thou, the spindle will have rotated 1/5
th of a revolution.
If your change wheels are set for a metric thread, use the formular
pitch mm/
Divs = carrage movement mm
Ramon when you work out where to find time, keep it a secret, you won't want to get killed in the rush.
Bez