Laser power problem on Laptop

Machine: Custom 50w Co2 Laser

Board: Cohesion3D mini

Firmware: GRBL-LPC

Problem/ Question: Hello Guys … First post here with a problem of course :slight_smile:
I have made my research in this forum and on the net in general and didn’t find any proper answer , I had also make a similar post on Lighburn forum when thinking that the problem was software based but didn’t get any answers … But anyway the problem is clearly hardware based … But I believe not from the board.

Let me explained , I have two Computers a PC and a Laptop (Zbook) and i am using Lightburn on Both (Same version same settings) . On my PC Laser works like a charm the only problem is that is far away from my laser and for that I have a laptop near the laser . When using the Laptop the laser tube working almost with the half of the power and the mA didn’t go over 0,7 … I have checked all the power saving settings on the laptop and all the parameters that can interfere with the USB port and didn’t find anything unusual.

Seems that i am missing something that maybe is too obvious or someone else have already bump in to it . Any help would be appreciated.

ps. i can provide photos if needed but like I said the wiring and the machine working properly on one computer , the problem occurs on Laptop that the laser working underpowered (even with the same USB cable).

This definitely seems like a software problem.

Load the same job - something simple, perhaps a 5 cm square - on both computers and instruct lightburn to save the gcode as a file. Post both files here.

Thanks a lot for you answer!

Here is the two Files , one from Laptop and one from PC.

Test Laptop.gc (7.7 KB) Test PC.gc (6.9 KB)

As I suspected, there’s definitely a difference between the two gcode files. On the laptop you appear to have the machine type set to GRBL-M3 and on the PC you have it (correctly) set to GRBL-LPC. M3 machines have a power range 0-255 and LPC machines have a range 0-1000. So, LightBurn is indeed trying to command the machine to 100% power in both cases, but since LightBurn expects different laser hardware on your laptop than it does the PC, the apparent power from the laser is vastly different. It’s firing at 25.5% when it should be firing at 100% as a result.

box3% grep S Test\ PC.gc
G1X198.757Y174.761S1000F840
G1S0
box3% grep S Test\ Laptop.gc
G1X198.757Y174.761S255F840
G1S0
box3% grep GRBL Test\ PC.gc
; GRBL-LPC device profile, absolute coords
box3% grep GRBL Test\ Laptop.gc
; GRBL-M3 (1.1e or earlier) device profile, absolute coords

So, set your device type to GRBL-LPC on the laptop and you should be all sorted out.

Yes! … so obvious and still didn’t see it :slight_smile: Thanks a lot for the help finally worked !!

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