Are there any settings to reduce risk of belt slip?

On my laser, I have a problem with belts occasionally slipping when changing direction rapidly when moving fast. I ruined a large pane of hardened glass yesterday due to that… For the X, I can tighten the belt, but I can’t find any way to tighten Y.

So, I wonder, is there some way to make direction changes smoother?

It sounds like you need to change your controllers acceleration settings rather than a lightburn setting. So it depends entirely on what controller you have :slight_smile:

It’s a Ruida, but I couldn’t find anything like that in the menu. Maybe I’m just stupid…

In which menu? Lightburn or controller?

Since you have Ruida/RDWorks, the parameters you probably need to change may be easiest to download/change/upload by using RDWorks (because I can’t remember if LightBurn gives you access to all of these parameters yet). Go the main settings window on the right side (the “system work plat” window) > User tab > “Processing” submenu area. You will find a bunch of acceleration related parameters to change there.

I’ll take a look. Actually, I never installed RDWorks, I went directly for Lightburn, as that seems to be the gold standard now.

But, I’ll install it and check.

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LightBurn machine settings allows you to change these values. I posted the section from the controller manual that defines the different settings here in this forum somewhere.

This is the post

Thanks, it seems to work! I set them very conservatively, so now it’s slow instead, but at least it’s a starting point.

You guys are my heroes!

Are you sure it was the belts slipping and not the stepper motor skipping steps? The belts should not be slipping unless they are very loose.

If you tighten the belts more then you increase the likelihood of the motor skipping steps (which means the motor does not have enough power to move at the requested speed).

Lowering acceleration values will help, but first make sure that the belts are tensioned properly - the original settings may be fine.

You can also increase the current going to the stepper motor by changing the dip switches on the driver. just make sure that the setting does not overheat the motor.

No, I’m not sure, but tightening the belt helped reduce the problem. If I pull lightly at the center of the belt now (on a 1000 mm bed), I have maybe 15 mm slack.

I’ll check how warm the motors get the next time I run it and see if I dare increase the current a bit.

But, first I need to check if the bed is level. It seems to get slightly out of focus at the far right, as settings which cut easily on the left side only go halfway through there. Always something to do…

15mm of slack I think is too much. I had the same issue on my Open Build ACRO 1000mm x 1000mm.
I put the gantry in the center of travel and tightened my belts. May be a combination of belt tension and acceleration settings.

When I say slack, I’m talking of how much I can pull the belt out at the middle, not how far I can pull it along the line of the belt. Honestly, i don’t think I could tighten it anymore, I wouldn’t be able to screw it together again, I was pushing my fine motor skills as it was.

Remember Pythagoras. 15 mm on one side and 1000/2 mm on the other side of a right triangle makes the hypotenuse very, very close to 1000/2 mm (500.22 mm). So 0.44 mm on the entire length. That should be close enough.

Guess I’ll revive this old topic here, but I’ve been having alignment problems in some of my cuts too. My stuff is very complicated - topographic maps with many, many, MANY line/spline segments, at least a dozen layers, lots of text, etc. Tightening the tension on the X-axis belt helped some, now maybe need to look at the Y. Lowered the acceleration settings (or whatever the settings are) and this helped as well. I can’t find a good source that explains - in laymen’s terms - what all these values mean. I’ve gleaned a little from the manual that came with my machine, plus what is written in this forum. I guess I have nothing to add here other than to solicit any more advice and a promise to follow up with the values when I am happy with the result. Oh yea, 80W CO2 500 x 700 Chinese “red and black” clone, Rudia controller (Lightburn of course!).

For me, tightening the belts and reducing all accelleration parameters helped. It slows down engraving, though, as it gets more “overshoot” when changing direction.

When I have some spare time, I’ll try to figure out the best settings, now I just reduced all accelleration settings to 1000 (iirc).

On a Ruida controller there are separate controls for engraving and general cutting. In Tim’s case, the general cutting settings for min and max acceleration would be where I’d start - lowering those would help prevent slip when in cutting moves, and “Idle Acceleration” is the accel used between moves - lowering that would help too.