Buildbotics Forum

HI Doug, et al, While I use the CNC on a regular basis, I haven't used my JTech laser (vintage late 2020) in a while, and now I'm having trouble with it. It used to run fine, and I don't think I've done anything to change its setup. The laser itself works fine, albeit at full power. I switched to the PWM controller as required in the BB unit, and everything looks right. However, the M3/M5 commands don't work and the S command does not adjust the laser output as expected (Using MDI). I checked the wires and they are connected at the breakout box and seem fairly secure.

I have a variety of lasered things from before that would indicate it was all working, including test logos and even a digitized photo that would otherwise have just been black. I tried checking the test pins on the J Tech and did not get any voltage, but I'm not sure if that is meaningful or not with a PWM signal. I'm just wondering if there might be some trick ot something I did before that I might be overlooking? Driving me a bit crazy.

Thanks,
Bob Zorich

Did you move the J2 jumper on the side of the laser driver to the input control position?

Also, verify that the full power setting on the PWM spindle matches the full power output to your laser. For instance, if you issue a command like M3 S250 to get the maximum power from your laser, then the PWM configuration should have 250 as the maximum out speed.

AHA!!! I knew I was just doing something dumb, not having run it in ages. Sure enough I didn't have the switch in the computer control position, but in the CW position. Not sure how or why it got moved to the CW position, since I had run it before, and it worked. Didn't even see that in the manual, so didn't understand that controlled that function. Oh, well. Thanks much, Doug!!

Bob