Laser dropouts failure

Well, I mean, overly complicated software solutions to avoid fixing hardware are something of a specialty for me. Let’s do it haha.

I do have the firmware source, and there aren’t any bugs I see that would explain the delay. There is a power lookup table that converts 0 to 100% power commanded from gcode into a PWM timer register value. Those values could be tweaked, but 100% is fully on, so nothing extra to be gained there.

I have written a post processor before, if we figure out parameters getting a program to modify the gcode is no issue.

I like the ruler idea - forgo the theoretical derivation and just do a direct measurement on the material. Generating that gcode is also pretty easy, I’ve already done similar things, would be easy enough to do.

I’m a bit busy this weekend but I’ll try and mock something up to get started soon.

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Where did you get it? I haven’t found a download anywhere.

You can find it in this thread:

I connected a wire to control the output of the PWM.


Grey is GROUND and ORANGE 24V. YELLOW is 3,2V and BROWN 5V.
Does anybody knows which PIN is which function? Or I will have to try.

Thanks. My naive expectation is that it would a bit more formal. Time to lower my expectations yet again.

They did claim that they would open source it completely when all the backer rewards were fulfilled (see post 7 in this thread): FYI:Source code of Snapmaker Firmware

Which actually has happened according to the SM team: https://www.kickstarter.com/projects/snapmaker/snapmaker-20-modular-3-in-1-3d-printers/posts/2967921

So hopefully we’ll soon see it as a repository on their github page soon: https://github.com/Snapmaker

I wouldn’t hold my breath.

The PWM arrives on RED. Saddly the PWM looks OK. So it should be the driver. Fixing software is more easy. The power 50% and 17%.

xchrisd Is there a way to get support for that? The circuit of the driver?

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**Hey, @Dirk1000 I am no snapmaker staff **

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Only people who have traced out the circuits have figured out schematics, and I haven’t seen anyone do that for the laser driver.

Snapmaker has not provided any design schematics or boardviews.

Does anybody knows how much current can be delivered from the 24V path and how much by the 12V path? I ordered https://optlasers.com/plh3d-series/plh3d-2w and want to connect it directly. In question I would use 24V.

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Hi @brent113

A few cases about the discontinuous laser beam were reported recently. Mostly, it is because the user does not operate the Laser engraving module correctly and the Fabscreen UI does not give a clear and comprehensive guide. We should have made the guide of camera calibration more user-friendly.

  • As you can see in the picture below, can you control the laser engraving module via the touchscreen?

  • How about the 3D printing module and the CNC carving module? Can these two modules work normally?

Step 1:
I think it will take 7 days that the returning module will arrive at our office. You can try the manual focus and that would work.

Go as the following steps:
Settings --> Laser --> turn off “Auto-focus”

Step 2:
Please check the default laser height in the touchscreen. The path is “Settings --> Laser --> Adjust Laser Height”

The height should be 15 - 20mm, and you can adjust it by yourself and choose a better one.

Hello Edwin,
please watch this video. A brighter spot means less power, due to automatic of the phone camera, a smaller spot is higher power. All set to manual, only M3 P35 and M5 used. In the middel of a few characters you see the change from 2%-3% to 35% and burning.
https://www.md-it.de/Common/Snapmaker_Laser_Error.mp4

Hello Edwin,
is the black core common ground? Or does the PWM has a separate ground?
Thank you.

@Edwin please have a look at this video :wink:

@Dirk1000 I’m pretty sure this was mentioned above so sorry if I’m repeating myself.

That’s the same effect I’ve noticed - it does not appear to be a failure of the laser module but instead an effect of engraving materials that take a bit of time to absorb enough laser energy to begin to engrave.

Add a delay at the start of each cut motion so the laser has time to darken the material and absorb laser energy better. I use 100ms, and that fixes that issue.

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I did so, G4 P100 after every M3 P35. No change, sorry.

Could you figure out which speed would engrave properly?
Like laser full power, movement 100mm/min, 200mm/min, etc.
I guess the same thing like @brent113, that the material needs more time to absorb the laser light.
May you even try other material like wood or so to double check your code?

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Not sure of this helps at all but on another forum that uses a laser running marlin, the same issue occurs at any speed above 25mm/s so I think its a marlin bug. You could try using grbl for laser, there is another thread on here about getting true grayscale where some one els ran grbl for lasering with good results.

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Hello,
I was wondering whether there has been a solution for the discontinuities in the laser cutting. Im trying to cut a map out of paper and have similar issues as Dirk described. Some parts cut out completely but some sections are just not cut (see picture) Used both 3000 mm/min / 600 mm/min speeds and 1500/400. Made no difference for me. It also didn”t matter wether controlled from the pc or send it via WiFi. Thanks.