Centroid Community CNC Support Forum

I am setting up a J tech laser using cnc12 v5.30 and I am having some issues. I brought my old shopbot pr96 out of storage and installed a new acorn board and set it up with schematic S14979 as it uses a Gecko 540 to drive the stepper motors and then wired the j tech laser system utilizing schematic S15049. The issue I am having is the cnc12 software is not sending signals to properly fire the laser from output 4 of the relay board. I know that mixing schematics is the most likely culprit but there is no schematic that I can locate for this combination. If anyone has a clue where I need to access the proper PWM to fire the laser it would be greatly appreciated. BTW, I use Lightburn software on all the lasers.

keith

Forgot to add the report

The PWM signal comes from output 2 through the DB25 connector. It does not come out of the output relays.
What you are seeing come out of Output4 is the laser enable signal.
If you haven't looked at the Laser Setup documentation, all of this will become clearer. Note how you need to modify the ribbon cable from the output relays.
https://www.centroidcnc.com/dealersuppo ... ds/326.pdf

Thank you for the quick response. I do have it wired with a break out board on the db25 just as it is in the schematic and the third wire connecting the relay is severed already so apparently my description was in error. I also have a acorn on my mill and another on my lathe so even if I come across as a total novice I do have some experience just for clarity. I also tested the laser per j techs suggestion of a 9v connected to the h2 with correct polarity and the laser works as it is supposed to. The issue I believe has something to due with the Gecko 540 driving the motors as it also wants to use the db25 connection by I need further guidance on which direction to take as I can't find any information pertaining to the use of both the Gecko 540 and the j tech laser.

I understand. Sorry I couldn't be more helpful. If the Gecko drivers are involved its outta my league.

Pin 14 on the Acorn DB25 header (H6) is the PWM +signal, is that where you have the laser enable circuit connected from? Do you have PWM setup properly in the wizard? In MDI, you can issue a M37 to enable the laser and then issue a S value of 0-100 or 0-1000 (depending on how you have it set in the wizard) to fire the laser. M38 will turn it off, or escape from MDI. The G540 manual shows that pin 14 on the G540 is for a VFD PWM signal, so if you have that connected at the same time, there may be an issue there.

If you are using Lightburn, you'll need to either make a custom "Start" and "End" code in Lightburn, or edit your files in Notepad++ to have the needed M37 and M38 codes.

grossmsj, Thank you for your help. I read one of your posts from May regarding " J Tech Laser with Analog Output AC spindle" in pwm configuration and tried that and it was a success.

Thank you also Sword for the input. I have Scotts header and footer already installed in Lightburn and it seems to work fine. I read about it in a thread that you were in.
Anyhow it seems to be working now after a short test so thank you to the both of you.
keith

Ha I just noticed Sword is Scott...Thank you very much no matter what your name is

Glad you got it sorted!