CNC Sewing machine question

In the case where the thread is broken, does it matter if the needle axis moves?

The other option would be for the thread-break detection to report the G-code line where the thread broke (this is fairly easy if it also monitors motion.program-line)
You could then possibly use the run-from-line feature.

andypugh wrote: In the case where the thread is broken, does it matter if the needle axis moves?

The other option would be for the thread-break detection to report the G-code line where the thread broke (this is fairly easy if it also monitors motion.program-line)
You could then possibly use the run-from-line feature.

I re-checked but unfortunately, i can not move backward needle axis. I must find a way to move back all axes without rotating needle motors. This is the point where i stuck.
I will use a thread sensor to detect the break. I can pause machine when thread broke signal is arrived. However i can not figure out how to go back and use start from here?

restart could, in theory, be handled by your GUI.
If it knows where the break happened, c.auto(linuxcnc.AUTO_RUN, line-number)

linuxcnc.org/docs/2.8/html/config/python..._linuxcnc_command_tt

(I would anticipate the machine remembering exactly where the break happened, and moving the workpiece to there before restarting.)

ahmetbm wrote: I designed the needle as an axis which made it easy to manage the sewing steps. However when it comes to moving backward or forward, it rotates the needle. So i am confused to change back the needle to spindle.

Yes, I think this is the wrong approach. You could configure the sewing machine as a "spindle", with a spindle on/off
and a speed setting. And, you'd need to come up with a way to "index" the sewing motor to the needle-up position.
So, when the program does M03, the sewing motor starts. When the program does M05, the motor slows to a lower
speed and then stops when a sensor detects needle up. Every M05 would be followed by a wait command (dwell G04 Pnnn) to allow for the needle to come to a stop. During sewing, the X-Y feedrates would be slow enough that the moves would be accomodated by material stretch. Only after the M05 and dwell would the X-Y axes move faster to move
to a new part of the embroidery pattern. I'm pretty sure a number of people have done this before.


Jon

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