Hi all, I am struggling to get my laser to fire correctly. I am working with a basic laser plotter running a JTech board with grbl1.1. I can get it to move, make shapes, etc. $32=1 However, the laser only fires when the Z-axis is changing. If Z position is 0, I can send it: M3 S100 G1 F1000 Z20 and the laser will fire while Z goes from 0 to 20. Same command again will do nothing since Z is already at 20. Send G1 F1000 Z0 and the laser will fire until Z counts down to 0. Also, with the above command, the laser flickers regularly; it's not on smoothly. I suspect a delay setting or something. I am not sure what I need to change to get the laser to fire whenever it is in G1,G2, and G3. I thought this is what laser mode did. I can fake it by making a change to Z in every G1,2,3 line but that doesn't seem right. Would be grateful for any feedback/ideas? Thanks, D
In theory, M4 in laser mode should only allow the laser to fire while it's in G1/2/3 feed motion, not whilst stationary nor during G0 rapids. M3 is supposed to give complete control, even allowing you to turn it on and off whilst stationary, but only in G1/2/3 feed mode. The flickering could be an issue with the driver, because otherwise it sounds like grbl's natural spindle pauses during standard $32=0 operation. If you send it G1 X0.01 F1000 M3 S100 M3 S0 M3 S100 one line at a time, it should immediately turn on, off, then on again, or if you've just done a G1 motion and are still currently in feed mode, just M3 S100 without having to program any motion will turn it on. Remember you can jog, but can't rapid or it'll kick you out whilst retaining it's programmed power state and level. Conversely, M4 S100 G1 X100 should also work just as you expect. I think maybe you're just putting it into feed modality second instead of first? If something like G1 X1 F1000 G1 X0 F1000 M3 S100 does NOT turn it on, then there's a problem.
Sweet! It was the M4 that made the diff. Thanks for making the point of the diff between `motion` and `mode`. That was it. Really appreciate the swift help! D
