Where is the laser engraving category?

Yes. It resolves the need to use two different versions of grbl for a spindle & laser.

If you have not already, download and install the latest version of PicSender as it will automatically change the grbl settings for both of the Modes when selecting them. Instructions are here for setting it up properly:


Great! Thanks.


Laser engraved at 200IPM with a Feed Rate Change of 20%. 1,387,637 lines of gcode streamed with PicSender to Larry’s MultiMode grbl 1.0c.


Larry’s MultiMode grbl 1.0c will run arc and G00 commands where the J-Tech LaserMode grbl 9g will not. In our testing of both firmware versions with raster files, the feedrate execution accuracy is the same without any dwelling from the S commands.


For the last two pictures that you posted, how long did it take to burn those images to the material? I’m very interested in getting a laser set up. Thanks in advance!

I can’t remember the exact time, but it was around 1-1/2 to 2 hours. This is the Laser Diode I have.



Do those performance settings I put into my old jtech grbl need to be manually put into the new 1.0C multimode version .?


Here are the instructions for Larry’s MultMode grbl 1.0c, PicSender & the grbl settings.


Thank you, Im running a makita , can i assume that this means nothing to the settings and i switch back and forth the same regardless of spindle or makita ?


Just make sure you have the PWM grbl settings $30, $31 & $32 set properly for Spindle use or Laser use and there saved to the corresponding grbl settings file that is either spindle.txt or laser.txt.


We did a Laser engraving feedrate test with Larry’s MultiMode grbl 1.0c and here is the results.

<img src="//discuss-assets.s3.amazonaws.com/original/3X/2/3/2391716116a3f201a5d5cb6ae7e2b50ea6ffb94c.jpg"width="498"height="500">

The size is 9" X 9" and we used the Extended Edge & Skip White in PicEngrave Pro 5. The image was Dithered Black & White using the Atkinson Algorithm in the image editor & the Max PWM setting is 255 & Min 0 so the laser would just turn on/off. The step over & step ahead distance is .007" and the Feedrate was set at 200IPM, even the Extended Edge. There is 901,805 lines a gcode streamed with PicSender and the run time was 1:10:06 (4206 Sec)

The travel distance of the X&Y axis in the gcode file was reversed engineered to a DXF file and the full length is 13968.822 inches.

13968.822 inches divided by 4206 seconds = 3.321 times 60 = 199.26 IPM. The performance of Larry’s grbl & PicSender when raster Laser engraving photos is as good as it gets and the movement was very smooth.

Good thing we have Kevlar reinforced timing belts on our Shapeoko 2 6W Laser Diode CNC machine. 200IPM and instantly reversing directions sure is jarring. :laughing:



I’m new to x-carve world, as lot of people here :smile:
Also got the laser with my kit, but I have one problem with it - I can’t focus it with low power. It always have so much power, so it burns everything in its way.

In UGS tried commands M03 S01 and others, it turns on, but with max power (i think) and burns as hell.
Turned pot counter clockwise ALL THE WAY (approx 21 turns), like in focusing instructions, but result is the same.
I’m so confused. What I’m doing wrong?

You must be missing a step in the J-Tech’s instructions. Did you switch back to TTL on the driver instead of CW?

1 Like

Thanks for suggestion.
Hmm… But I’m stuck in step 5.
“Switch the front switch (mode selector) to CW (towards the power switch). The laser is now on, but will not be lasing because there is no current.”
My laser is on and instead of just showing light it burns like with full power… :frowning:

Switch back to TTL is in step 13.

This statement is why I was wondering if you missed a step. In CW mode, the S commands have no effect with the laser power. It appears you may have turned the potentiometer in the wrong direction.

The best person here to assist you in this process is @JTechPhotonics

1 Like

Hi Tom-

I updated the focusing instructions on the website to be super explicit on what to do now. If you want to use the potentiometer to focus the laser you need to turn it down so there is just a very small low power spot. This is done by turning the potentiometer counter clockwise, not clockwise. Counter clockwise is down and clockwise it up.

I updated the instructions on how to do focusing without needing to use the potentiometer. You will send a command (either M03 S1400 or M03 S5 depending on your firmware installed) in UGS to turn the laser power down. This is the easiest way to focus the laser. No messing with the potentiometer at all.

The new instructions are here: Focusing 101

Hope this helps!



Yes, you’re right. By mistake I turned clockwise, not counter clockwise. Sorry guys! :persevere:
Thanks for new instructions, did everything like you typed and my laser works like charm. :wink::tada::champagne:

Only one question, do I need to do “Method 2” step 15., because I changed the potentiometer position?

You can just turn the potentiometer clockwise until it is all the way up (just keep turning if you are not sure - you can’t break it). It will put the current within a few percent of perfect with the current limiting jumpers on JP1 in.

3 jumpers = ~1.5amps (2.8W laser)
5 jumpers = ~2.5amps (3.8W laser)

If you really want to be perfect on dialing in the current then you can use the meter, but it is not really necessary.


Ok, thanks for information.:thumbsup:
This is the fastest support I ever had. :slight_smile::thumbsup:



Xcarve Jtech and picsender/engrave is an awesome combo.