Lightburn issue? Controller issue?


(hayden) #1

Hi there - I posted this in the cohesion3d support forum too…not sure whether the issue is board related or software related.

Machine: K40

Board: Cohesion3d

Firmware: Smoothie

Problem/ Question: Background - I just upgraded from the nano board to a Cohesion3d board with lightburn. When setting up the controller board in lightburn, Cohesion3d wasn’t an option in the dropdown. I picked Smoothieware. Sounds like that was the correct thing to do. As a sidenote, I did have the software search for the engraver and it didn’t get a hit. So I set it up manually.

Now for the problem. I can’t seem to get good fills. I’m not sure if there is some setting that is off, but I’ve read and re-read the documentation. I’ve spent hours trying different settings…with no avail. Attached is a picture of what I mean. The one that looks like it was done by a dot-matrix printer (Trey) was done with lightburn/cohesion. The one that is smoothly rastered (T Highfill) was done on the nano/k40 whisperer. Am I just missing something with the settings? Is it a configuration issue? For the one that says Trey, I used the Text tool in Lighburn.

One more note - for “Trey” I used the “fill” setting.

Thanks in advance!


(Oz) #2

What did it look like when you previewed it? (button that looks like a monitor on the top toolbar, or press Alt-P).

If it looks like that in preview, you most likely have doubled-up vectors directly on top of each other, cancelling one another out. You’ve made no mention of where the text was generated, but if it was imported from an AI file this is really common, if you have both stroke and fill applied.


(Oz) #3

Another possibility is that you’ve set your speed too fast and aren’t using overscan. That would result in high power at the start / end of the scan line with less power in between. When asking for help, it helps us if you include things like power and speed, and anything else that might be relevant. To much info is ok. :slight_smile:


(hayden) #4

I created the text from within Lightburn. No import. The text, “Trey”, was the only layer and the only item on the layer.


(hayden) #5

I just ran another test…using “Test” this time. :slight_smile:

Power at 100%. Speed slowed down to 30. Screenshot below and output below.


(hayden) #6


(Oz) #7

Power is 100% of what? As in, what milliamps are going to your tube when you run the file? The C3D board sets power as a percentage of what your analog dial or digital panel is set to, so if that was too low, it’d be 100% of not enough power. :slight_smile:

When you ran the same test on the nano, what were your settings for power and speed?


(hayden) #8

The digital panel was set to 100% as well n the test example. By comparison, with the nano board in the example that says T Highfield at the top, I was running 80% at 70 mm/s


(Oz) #9

Do you have an ampere meter? Running at 100% can burn out the tube if you don’t know what you’re actually sending it. My test K40 can’t be safely driven above 50% - they vary a lot. Try running at lower power. As counterintuitive as it seems, it might actually boost your output.

It’s also possible that you need to tune the PWM coming from the C3D - some power supplies don’t deal well with the digital signal, so you need to slow it down a little for them, and the C3D forum will have guidance for how to do this.


(hayden) #10

Thanks for the help. Good news is, I plugged back in my nano board and used K40 whisperer and got beautiful results again. So at least I didn’t burn out the tube.

I’ll head back over to the C3D forum and see if I can figure out what PWM tuning is. The C3D board was advertised as “drop in and go”…doesn’t seem to be going down that path though.

Appreciate the guidance thusfar! I’m excited to get this up and running.


(hayden) #11

I’ve posted an update in the C3d forum as well, but unfortunately, changing the PWM setting didn’t work. Any other thoughts?

Is there some think I could try to rule out hardware?


(Oz) #12

Save the GCode to a text file, then copy & paste it into this online sim: https://nraynaud.github.io/webgcode/

You can also just look at it in a text editor to see if the code looks right.


(system) closed #13

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