RAMPING SPEED with atkinson image engrave? why?

LightBurn Software Questions
1

hello guys, can anybody help me?
i just finished my router and installed lightburn, i engrave images and i noted that if i choose THRESOLD or HALFTONE method with horizontal engrave the movement of the x axis is smooth and linear (same velocity during all the lines), but if i choose atkinson, dither, stucki, jarvis or others methods the movement of the x axis is not linear, is changing speed ramping up and down during the lines, is that normal? is literally possible to see and hear the speed that is changing during the line :frowning:
CONSTANT POWER MODE IS DISABLED DURING THE TESTS
is it possible to engrave images with the same speed during all the engrave?
which parameter should i check to solve this problem?

i’m using arduino uno + grbl 1.1g with pwm control, i setted the image engrave speed = as the maximum speed in machine settings to avoid this problem, fast whitespace scan is disabled but the problem persist…

2

I haven’t worked with these enough to know if this is expected or not but I don’t see why that would be the case.

I thought for sure this was going to be an issue with fast whitespace until you listed that.

What do the previews look like for each type? Is it the same set of traversal paths?

I’d suggest taking a look at the g-code. Do you actually see the speed changes in the code?

1 Like
3

i think my problem is that arduino uno and grbl are not fast enough to process complex gcodes and so are stalling during the lines, in fact if i reduce the speed from 6000mm/min to 2000mm/min (i have set 160steps per mm) the problem disappeared, do you know the limits of grbl? i think it can handle 30khz at the same moment (that have to be splitted between axes), right?

4

I’m not aware if GRBL has an inherent limit but I do know that faster 32-bit MCUs vastly outperform the Atmega in the arduino uno for these tasks.

Based on your finding I bet you’re dead on about the speed limits. I’m actually impressed that you can engrave even at 2000 mm/min.

5

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.