TinyG for 60W CO2 laser

Hello,

I’m setting a (chinese) 40W laser these days, and I think I’m going to remap the switchs and pots existing on the machine to my needs.
The “test” button will probably keep its function, which can be useful.
The “enable” button will probably be de-connected, and the cables remap to one or several security switches: that way the laser can’t be triggered if doors are opened.
The laser command (that was connected to the board that came with the laser) will be connected to the spindle out of the TinyG. In my case a Arduino due + gShield, but it shouldn’t change anything.
And last, I plan to remap the potentiometer that is used to set the current running trough the laser to a small DAC converter: my power supply doesn’t understand pwm, so here is what it should go: first, an otpocoupler to transmit PWM, without risking overvoltage/current on the board. Then, a DAC converter, as seen here. That way a 0 phase will give a LOW state on the laser, and a 100% phase will give a high state on the laser, resulting in max power.

Just hope it will work like I want. 🙂

For now, my parameters are quite simple:
Any axes but X and Y are AXE_DISABLED, any motor but 1 and 2 are MOTOR_DISABLED.
VELOCITY_MAX is around 25000
JERK_MAX is 10000. A high number — if possible: the gantry need to be light and have little inertia — allow to have fast acceleration and deceleration: that way laser “power/distance” (not very clear) is about constant. You don’t need to ramp the power up and down following the feedrate acceleration and deceleration.

Pwm is to be set up according to the hardware you have. In my case it’s a 40W laser, which power is usually controlled by a pot. I’ve simply connect the pot wire to the output of an optocoupler that transmits the pwm output of the TinyG board.
The PWM frequency is 500Hz, but I need to fine tune it: sometimes it causes a strange vibration in the power unit.