LASERS…I could use some info

New Home Forum Mostly Printed CNC – MPCNC Hardware Development – MPCNC LASERS…I could use some info

This topic contains 65 replies, has 22 voices, and was last updated by  Daniel Dunn 7 months, 2 weeks ago.

Viewing 6 posts - 61 through 66 (of 66 total)
  • Author
  • #85578



    I may be little help here as I don’t usually swap tools out on my MPCNCs. As a result, I’m still using a Hicwic quick-change mount on my laser-engraver MPCNC… the mount is not terribly rigid for other tooling but is fine for the laster.




    I also have a 3.5 watt laser mounted on an  Eleksmaker A3 laser engraver… which doesn’t offer a fully-implemented Z-axis as delivered. So I used a BB bearing linear slide by 3DPRINTINGWORLD to give me Z-axis that works nicely for adjusting the laser focus…


    I both cases I Pawpawpaw85’s 40mm air-assist for diode lasers…

    — David



    Having a little laser trouble.  I’ve got the 3.5w from Banggood (LA03-3500).  I made the firmware modifications to move 5v from pin 9 to 44.  I have verified with my multimeter that the voltage on that pin changes with changes to the “Fan” speed.  I have verified that I get the same reading at the connector that plugs into the laser driver board.

    With that control signal wire disconnected, when the laser module is powered on, the laser beam is on at full power.  I can push the button on the driver board to change it to low power output and back.  But, with the control wire connected, I never get any light from the laser.  The fans come on, the LED on the driver board comes on, but the laser will not come on whether the fan is set to 0 or 255.

    Do I have something wrong, or is something probably wrong with the laser driver?




    You probably need to supply a few pictures of your setup and the laser’s control board. I’ve got a couple of Banggood 3.5 watt lasers with different control boards… though they both have a TTL input and are hooked up to a RAMPS, pin 44. Are you using RAMPS?

    With the TTL input “floating” (disconnected), it’s enabled (internally pulled up?) and the laser turns on as soon as you apply power… a bit akin to turning on the light switch on the wall and then turning the light on and off with the circuit breaker 😉




    On the driver board, top connector on the left goes to the two fans, the bottom left goes to the actual laser. The top connector on the right side is the 12v power. The bottom connector on the right is the TTL from the RAMPS board (D9 remapped to D44).

    When 12v power is applied and the TTL is disconnected, the laser comes on full power. When 12v power is applied and the TTL is connected, nothing happens other than the fans spin.




    Ok, I just zoomed in on the pic of the board and I see the problem. Polarity is reversed on the TTL. I cut that connector off the radial fan when I spliced it in to the existing fan wire. And I never paid attention to the polarity markings on the board, just used it as it was.


    EDIT: Confirmed. I swapped the wires and it works perfectly. Now to just get it dialed in and figure out how to use it

    1 user thanked author for this post.

    Daniel Dunn

    Any final verdicts yet on what laser to purchase for engraving or cutting? I’d commit to experimenting with y’all, but funds are a little low at the moment.

Viewing 6 posts - 61 through 66 (of 66 total)

You must be logged in to reply to this topic.