Cancel current movement, keep machine on



  • I'm aware of M0 and M1. These stop after moves in buffer are done. There is also M112, which stops right now, but needs a reset to continue. Can we have something in between?

    In my application, this allows jogging using a keyboard/jog box: At key down, a slow move command towards machine limit is sent. At key up, a stop command goes out. The machine stops, using set deceleration settings. Everything is still on, the current position can be found and so on. I can see other use cases for this in CNC world, and maybe with 3D printer setup, too.



  • @JuKu said in Cancel current movement, keep machine on:

    Can we have something in between?

    +1
    Caveat: No experience of Duet CNC use, but I've read the rlevent bits of the docs and think this is another place to adopt some of the conventions set in the small cnc/engraver world.

    You need three commands 'Hold, Resume, Reset' which should also be tied to IO pins (via Macros, or whatever).

    • Grbl's implementation is described here, this is very much a standard way of doing things in the CNC world where grbl's developers come from.

    None of these depower the drivers, allowing positions to (mostly) be preserved.

    • The 'reset' is a soft reset, if the machine is in motion it assumes it might lose position and throws a (resettable!) warning.
    • Hold does exactly what it says on the box, brings the machine to the fastest halt possible from current position while preserving status and movement queue.
    • Resume is the opposite, also doubles as a 'start' button for jobs.

    I strongly recommend reading the linked doc; it gives a good overview of what to be aiming for; even if the actual implementation is different (eg M commands, not grbl's escape commands, etc).

    The simplest CNC pendents around just have three buttons. I use one:
    tulip-buttons.jpg
    Mine also has a terminal for probes; it's wired to the controller. The lump underneath is a Pi3 A+ with LaserWeb etc. which acts as a SBC for the system.

    • Disclaimer, this is not a Duet machine, it runs the crappy controller that came with my delta printer and grbl-mega. Actually a very good combo for the task at hand.

Log in to reply