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Mach4 General Discussion / Re: PROBLEM WITH LASER START-UP POWER WITH PMW MACH4 AND POKEYS
« on: November 22, 2021, 07:35:25 AM »
Hi GréG,
You have to bear with me here because I am better at doing things than I am at explaining them but…
CV = Constant Velocity.
You can have a Gcode file containing many G1********* commands on many lines of Gcode which will be performed as one seamless operation within the rules of your Mach4 Constant Velocity settings. If you then insert an M3 or M5 command within those lines of Gcode the CV chain will be broken and a delay will be introduced. This delay may not be that noticeable with conventional machining but it will be noticed when using a laser.
For this reason the M62/M63 commands were introduced within Mach4 so they can be inserted into the Gcode and the file will run without breaking the CV chain. As mentioned previously I do not know about the latest Mach4 build (I haven’t tried it) but previously the S### command also broke the CV chain and that is what you are seeing in your excessive burn marks – the delay it introduces is noticeable.
It is only within the last couple of months that the Pokeys Mach4 plugin has supported the use of the M62/M63 command set so you will need to be using their latest build of the plugin and also the latest Mach4 build.
If you want reliable laser operation then my best suggestion is to do as I have done and incorporate a simple circuit to gate the PWM signal with the M62/M63 signal, as I explained earlier.
Tweakie.
You have to bear with me here because I am better at doing things than I am at explaining them but…
CV = Constant Velocity.
You can have a Gcode file containing many G1********* commands on many lines of Gcode which will be performed as one seamless operation within the rules of your Mach4 Constant Velocity settings. If you then insert an M3 or M5 command within those lines of Gcode the CV chain will be broken and a delay will be introduced. This delay may not be that noticeable with conventional machining but it will be noticed when using a laser.
For this reason the M62/M63 commands were introduced within Mach4 so they can be inserted into the Gcode and the file will run without breaking the CV chain. As mentioned previously I do not know about the latest Mach4 build (I haven’t tried it) but previously the S### command also broke the CV chain and that is what you are seeing in your excessive burn marks – the delay it introduces is noticeable.
It is only within the last couple of months that the Pokeys Mach4 plugin has supported the use of the M62/M63 command set so you will need to be using their latest build of the plugin and also the latest Mach4 build.
Quote
Here is my problem and the question: how to vary the laser power with pwm and M62 / M63 during machining?
If you want reliable laser operation then my best suggestion is to do as I have done and incorporate a simple circuit to gate the PWM signal with the M62/M63 signal, as I explained earlier.
Tweakie.