Just Finished Building an MPCNC Primo trying to connect with Lightburn

Hello All,

I just finished building a MPCNC Primo milling machine and I want to use it as a laser engraver as well. I printed a mount and put an Aenbuslm laser on it. My controller is an SKR PRO 1.2 running 2209 drivers. The firmware is Marlin 2.1.1 provided by V1 Engineering.

My problem is if I manually create a new marlin device I can’t move the axes in the “Move” tab. If I do “find my device” it works but comes up as a GRBL machine. Just out of curiosity I messed with that and it moves the axes but get’s in a funk when I fire the laser.

Any help would be greatly appreciated.

One other thing, I’m attempting to fire the laser off of PC9 on the SKR Pro 1.2 board.

Then you must select the Marlin device type. Start with this doc and the suggestions at the bottom:

You must set the device parameters manually.

IMO, Marlin seems sub-optimal for laser control compared with essentially any other firmware:

https://forum.lightburnsoftware.com/search?expanded=true&q=marlin%20order%3Alatest

Flashing a version of GRBL may make it behave better in its new role.

That sounds like a power supply problem, where the additional laser current droops the voltage enough to brown-out the controller or the rising edge of the current induces enough noise in adjacent wiring to reset it.

After you settle the Device configuration, make sure the Console doesn’t show the controller resets when you fire the laser with a manual command.

Thanks for the fast response!

I have a separate power supply for the laser and did the 2-2’s into a 3 method as such:

image

I have found that when I send the .gcode from a thumbdrive in the TFT port and I can watch the progress that it’s exciting the FAN0 output of the SKR and not the PC9. Thinking I might switch the laser output to that instead. What do you think?

Could I flash the SKR Pro 1.2 with a GRBL firmware?

Would I still be able to use it as a milling machine?

If that’s the output turning on when the laser should be firing, then rewiring the laser connection seems the least awful way to make the thing work.

No opinion, as the myriad hardware types lie beyond my comprehension.

Long ago, Marlin started as a fork of GRBL intended to run 3D printers and became exceedingly specialized for that niche. It now seems to be gluing on features of a general-purpose CNC controller, while hobbled by a (reasonable) requirement of backward compatibility with all the 3D printer weirdness.

IMO, it would make far more sense to use a CNC controller on a milling machine and a laser controller on a laser machine, but I admit to some bias based on watching folks around here having plenty of hassle while making a 3D printer controller behave like a laser controller.

GRBL and its recent 32-bit forks are CNC-based controller firmware with reasonably capable laser functionality, so, if you can use one of those forks, it’d make sense to try. But that’s just me.

I built a machine originally as router, then added laser. Both running off GRBL 1.1h

Thanks to both of you for your help!

I think I’m close to having control directly from Lightburn. I can now generate .gcode in Lightburn and take it the controller and burn a job successfully.

My problem is in Lightburn itself. I setup the Marlin device manually (the size and name). Setup the device preferences (inline commands, baud rate, start gcode). The laser tab will go from disconnected to “ready” but the console tab says “waiting for connection” and I get no axes movement from the buttons in the move tab or the ability to fire the laser.

One of my favorite features of Lightburn is the ability to move and fire the laser to get the best placement.

I really think I’m close though.

BTW I did figure out with help from some friends on the V1 Engineering forum how to get PC9 set as the laser output.

Ready means nothing as far as being actually connected. Have you tried all com ports?

No, it only offers me COM6. Is there a way to try other ports?

Go to device manager ports (com&LPT) and see if laser is listed there. Maybe a driver you need to download for your controller. What is your baud rate set to in device settings?

I`ll check out this afternoon!

Try changing baud rate and toggling DTR in device settings

Thank you all for your input on this! Turns out the problem had something to do with the fact that I installed Repetier Host before I installed Lightburn. If I launch Repetier Host and hit connect and then quit the program and go into Lightburn Voila! it connects perfectly. Before anyone thinks I’m claiming this as my idea I have to give credit to M1000 Waiting for Connection on Marlin. I read his post about using Pronterface and thought it might be the same with Repetier Host.

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