New C3D on K40 install and raster fill speed does not change with settings in lightburn

K40 M2 Nano

C3D Laserboard

Firmware:"I have a new board and I’m using whatever it came with

I have just installed a new C3D Laserboard on my 4 month old K40. So far, I have gone through the documentation of setting up my bed size and configuration the best I could via the docs guidelines. I am not clear as to the exact model of my stock K40 Stepper motors so I am including pictures of that and my setup in general as well as my config file, that I may have made mistakes with.

My problem now is that no mater what I have done so far, raster fill speed ( these are shapes fills, not images) does not change when adjusted on layer settings in Lightburn and seems to be moving extremely slow. What Lightburn predicted would take approximately 7 min took the better part of 20, (the project that took 20 min is not shown in the photos below)

Lightburn units are set to mm / sec. I see the config file is listing mm / min.

config.txt (28.4 KB)

Any help with this will be greatly appreciated.

Stepper Motor:

Lightburn Screen Captures:

Job on Bed:

Other photos of my setup:

Ah, the K40 Mini. It’s cute. Nice GLCD mounting approach.

Did you lower any values in the config file as per this guide?

A video of this happening could help me say for sure what we should look at.

Hi Ray,

I went through the config settings and have modified them as per the guide, and then again trying to improve my speed but nothing seems to have any affect. My original config (after adjusting is posted above)

I am using the Smoothie Cluster Firmware

Here are the layer settings:

Here is what Lightburn predicted:

Here is the video of Lightburn executing the layer, what was predicted as 16 sec took 29 sec to complete.
This time doubling scales with larger jobs.

Hopefully this video helps, if not let me know what you need…

Thank you!

Quickly touching upon this bit - you have to tell LightBurn the same values that are in the config file for that prediction to be accurate:

Also FYI: cluster doesn’t matter for a simple raster fill, only for images. This would be a max speed or acceleration limit in the config file, most likely.

x_axis_max_speed 6000 # mm/min
y_axis_max_speed 6000 # mm/min

These are very low. That’s literally saying the max speed per axis is 100mm/s. That’s your issue. Bump this back up. A lot.

acceleration 1000

If there’s still an issue, maybe bump that back up to 2000 - 3000.

Finally, 500mm/s is fast, and the K40 isn’t all that sturdy to permit it. I’d recommend making the above changes and running the job in increments of 100mm/s speed, and (hopefully) observing it go faster and faster each time, so that you know what, 100, 200, 300, 400, and 500 all look like.

That solved my problem! Speed adjustments at the laser are now tracking nicely with what I set in Lightburn and time estimates are also greatly improved.

Thank you so much, Ray for your time, effort and added insights!

Looks like I’m off to the races… :smiley: