Need to make a thread dial

[jabraham17]

I just started using an Emco Maximat V10 that I have and I am impressed with how well this small lathe works. I just finished making a lower unit prop shaft for an outboard motor and when I did this I had to cut some threads. At this point I realized that it has no thread dial. I managed to get the job done by not disengaging the feed (and using reverse to return).
Going forward, I want to make a thread dial for it. If anyone has done this, can you tell me how many teeth the gear needs to have, i've seen others with 16 or 32. and any other details that I may need to know about this. I will only be cutting American pitch threads due to the current gear set in the machine.
Thanks in advance for any advise. Josh

 

[jabraham17]

Thank you Jim!
As a matter of fact, I just measured the screw. I has an O.D. of .780 and it is LH 8 t.p.i
I will start with the gear and work my up from there. Do you want to sell an extra gear if you have one?

 

[martik777]

Wow $6!!!!!!!!!!!!!!!!! Can you make the small gear for a south bend 9 back gear shaft for that???? Mine has sheared off and was thinking I could press fit one on with a key slot, Nylon should work at those low rpms. Let me know

 

[jabraham17]

Jim, I recieved the gear, Thanks! It should work just fine for what I need.
one other question, how many indication marks would I need on this thread dial that I am making? Thanks, Josh

 

[GK1918]

Tipical being a $100 even a used one for years I ran a speedometer cable off the lead screw with a
red neck gauge and needle, figured the timing and marked it with a sharpie. Since I bought one from
an atlas for 20 bucks ebay. the gear could be bigger but it does work, problem is that keyway on the
south bend. My other big lathe has no keyway and I made the gear from a brass washer perfect.

 

[HMF]

Here are some good threads on making a thread dial that I found: