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Author Topic: Mach3 pauses at M3 and M5 commands  (Read 525 times)

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Mach3 pauses at M3 and M5 commands
« on: July 29, 2018, 08:18:15 PM »
Hi All,

I'm really new to Mach3, infact, I installed the demo just yesterday. I seem to have it working and my motors are moving and so far I haven't hit any major snags. I was able to search answers by members here and the video tutorials were very helpful. I was running some test gcodes. and since my machine is a laser engraver, the M3 and M5 commands turn the laser ON and OFF. The M3 command is also accompanied by a S value which is essentially the PWM value for the laser power scaler. These gcodes were originally made for the grbl firmware. Every time the program reaches an M3 or M5 commands, it pauses for a second and then moves one. This causes burn marks on the material during the pause. Any idea how I can disable these pauses? I've set the spindle spin up and spin down delays to zero under Ports and Pins settings but that does not seem to do away with this delay. Also the most recent version of grbl uses M4 to ensure that the laser is turned on only when the machine is moving. Is the M4 command supported by Mach3?

Offline ger21

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Re: Mach3 pauses at M3 and M5 commands
« Reply #1 on: July 29, 2018, 09:01:29 PM »
I think that you want to use M10/M11, which were created for controlling a laser.

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Offline Tweakie.CNC

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Re: Mach3 pauses at M3 and M5 commands
« Reply #2 on: July 30, 2018, 01:50:17 AM »
The M3/M4/M5 commands are far too slow for laser work and as Gerry has mentioned you need to be using the M11P# / M10P# commands.

Even if you use the M11P#/M10P# commands you cannot directly transition from GRBL generated Gcode because under Mach the S#### commands will break the Constant Velocity chain and you will still have pauses which will create unwanted burn marks.

If you want to reproduce 8 bit photographic images then please have a stroll through this thread, a number of solutions are described; http://www.machsupport.com/forum/index.php/topic,12444.msg242678.html#msg242678

Re: Mach3 pauses at M3 and M5 commands
« Reply #3 on: July 30, 2018, 02:05:50 AM »
Interesting thread. Thank you for sharing that with me. I will try the plugins listed there. Another thread that I came across which lets users use the JT Photonics laser drivers with Mach3.