The question of proper threading

Hello.
I have been using the system not so long ago, maybe since 2014, and I cut a lot of threads. And I was always wondering why they do not always turn out smooth? What settings should be on the lathe, which encoder, what rotation speed?

I tried to increase the distance in front of the thread to stabilize the speed. I tried to exit the thread a multiple of the thread pitch and the length of the thread a multiple of the thread pitch.
it still turns out very badly.
Please teach me how to cut the thread correctly.

the simple question, why does the tool pause before the exit taper?

pkasy wrote:

the simple question, why does the tool pause before the exit taper?

I think it might help if you gave more info ie. Do you have an encoder onthe spindle for A+Z and post your ini and hal files with the Gcode you are using to thread with.

ok.
I have same problem at all my different cnc lathes.
It does not depends on one exacly machine.
Spindle has encode ABZ 2500 ppr.
GCODE:Hal:


It looks to me as working with G61 - tool stopped before exit taper.
If I put G64 P0.25 - it moves much better.

But who cut threads with G64?

here is a EMC code:
so in my case taper_pitch < pitch, why?
cutting feed is 600 mm/m as I see at Axis, but at tapper feed is 300 mm/m (about).
but they must be same, right?

G76 doesn't seem to use an encoder to move. I tried to rotate the spindle with my hands on the engine turned off. The EMC waits for a full turn and jumps. and not always.

the video turned out to be of poor quality, since there is no tripod for the phone.
but here is a screenshot of the signals from the encoder when I rotated the spindle by hand. as you see, everything works.
but the cutter stands still and waits for something. sometimes jumping, sometimes follows.

pkasy wrote:

the video turned out to be of poor quality, since there is no tripod for the phone.
but here is a screenshot of the signals from the encoder when I rotated the spindle by hand. as you see, everything works.
but the cutter stands still and waits for something. sometimes jumping, sometimes follows.

Is the encoder counting the correct way ie is it increasing +ve when turning the spindle

that's a very good question, thanks.