Rivett Thread chasing dial

On the other lathes I've used, the thread chasing dial was marked 1 through
4, with lines in between, and I learned the rules about when to engage the
half nut for odd, even , and half threads.
The thread chasing dial on my Rivett 1020S is marked 1,2,3,4,5,6 with no
lines. I assume there is a different set of rules in play here?
Dan
Reply to
Dan Cassaro
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Dan,
How many threads per inch does the lead screw have?
I believe that most are 8 threads per inch, maybe yours is different.
Another rule is you can engage the half nut any place it will engage if the number of threads on the lead screw will divide into the number of threads you are cutting evenly. (Or at least I think that is the rule of thumb I remember, maybe someone else can confirm it).
Vince
Dan Cassaro wrote:
Reply to
Vince Iorio
It's 6 TPI, and the dial advances two digits per 1" of carriage travel. So, I assume that if the thread is a multiple of 6 tpi, I can engage the half nut at anytime, and if a multiple of 12 at any digit?
Reply to
Dan Cassaro
Dan,
As I understand it, yes, you can engage at any number if you are cutting 6, 12, 18, etc. threads. But you might want to run a few tests to verify it first.
Vince
Dan Cassaro wrote:
Reply to
Vince Iorio

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