Laserweb 4.0 problem with burning pcb

Hello all,

I have Chinese Eleksmaker A3 Pro laser engraver with 2.5W laser. When I try to burn my pcb from JPG or PNG file, Laserweb makes it very “fuzzy”, meaning lines are not correct.
Check attached image. I couldn’t put second image because I’m new user.
By checking Laserweb preview, image looks good but not when it is burned. I have made spring tighteners to keep all the belts tight enough, every bolt and screw is tightened, nothing loose anywhere.

I also have newest grbl 1.1h installed on Arduino Nano on my engraver.

What could cause this problem ? Is it bug perhaps ?

Or is there fix to this already ?

Thank you all in advance for help

This very much looks like a physical problem that your mechanism has backlash (I’m guessing in X though you didn’t say specifically) and there is no scale reference.

Does it change if you engrave at a different speed? (Test with something other than PCBs until the engraving is clean, of course; don’t waste PCBs)


Thank you for your response :smiley:. I don’t think it’s mechanical problem with my engraver. Like I said, I have made spring tighteners to keep all the belts tight enough, and they are tight enough, to me at least.
Check attached image.
It looks pretty good to me. It is made after I made belt tighteners for my engraver.
It is made with same speed (100mm/min) as that earlier pcb. I have printed it from SVG file.

By the way, I don’t waste PCBs, It is just spray paint on PCB. I can clean it with acetylene and then I just spray it again :wink:

1 Like

This is clearly a backlash issue (mechanical) in x direction. Also in your last picture you can see that the letters don’t end at the same x position as started.

Check if the pully is tight on the stepper shaft.


Thank you for your response :smile:

I checked again that everything is tightened properly, no help. Check attached images.

Upper part of first image is part of last print, and second image is Laserweb preview of loaded JPG image. Preview looks like it should be, but still print is not.

I agree with @cprezzi that it looks like mechanical backlash. The only other possibility that I can imagine is that your laser head for some reason responds slowly to turning on and off

If it’s mechanical backlash, it will be approximately the same impact at different speeds. If it’s some electrical problem in the head, then the slower you cut the better it should look; cutting at half the speed should be half the offset. If it were mine, that’s the first test I would do.

1 Like

It could eventually also be the lense that is loose. I had that on my diode laser and solved it with a gasket ring (rubber).

1 Like