A question for Granite owners

[44man]

When cutting threads that must stop at a boss or shoulder, how do you stop the machine before the cutter runs into the shoulder? For that matter, even with a shank with no shoulder, how do you prevent over run?
Since you can't shift out of gear or change anything when thread cutting, I am worried.
Yeah, had the same problem with the 1220. Had to shut it off early, sometimes too early and sometimes too late.
Course threads where the carriage is moving faster is the worst.
I am not a machinest so please give me some pointers.

[garandsrus]

44Man,

One thing I have read is to turn the cutting tool over and cut the threads with the carriage traversing away from the shoulder.

John

[44man]

Thats what I was going to do but still have to reverse and go back to the shoulder! Of course the cutter can be backed out until back in position. I know I won't be able to use the leadscrew hand crank. Might be able to turn the belt and pulley by hand for a fine adjustment though.
Thanks for the info, makes a lot of sense. Sure glad I have a speed control now and I put the slow speed pulleys and belts on to slow everything down. I now have a choice between 400 and 3000 rpm's.

[Morgan Astorbilt]

I've never even seen a Granite lathe, but from what you've said, it sounds like you don't have a threading dial to allow you the back out, return to the start, and re-engage the thread. Also 400RPM seems pretty fast for threading, I use 35 or 48RPM.
Morgan

[e15cap]

Sounds fast to me too. You should have a thread relief cut where the threads stop so your cutting tool has a place to just "idle at". You may have to stop short and and pull the chuck around by hand to stop where you want. Best Roger

[44man]

I have it figured out! :???: I do have a threading dial but it was not set to engage the lead screw. I adjusted it. All I need to do is to open the half nut to stop.
The speeds I listed are for the highest speed with each belt change. I will top out at either 400, 1500 or 3000 rpm's.
The speed control itself is variable and starts at zero. I can cut slow as crap now! :drinks:
Thanks guys

[454PB]

I ran a Granite for a while. It had a D.C. motor, and would stall out and stop on heavy cuts. Has this been a problem for you?

[44man]

I just got it set up but it should not stall with the low speed pulley upgrade. It really multiplies the motor power. I don't think anything will stop it now. It also make it easier on the motor.
My old CB would stop and slip belts if I cut deep. I could never get them tight enough.
My problem is that it is so different from my old one it is like stepping out of a jeep into a caddy.
Smithy is sending me a video.
I bought this one used (barely) and the owner forgot to give me the video.