I have a Sculpfun S30 Pro Max. I was originally using the trial version of LightBurn from a few versions ago, and everything worked great. I hadn’t used my laser for several months and the trial had lapsed. So I purchased a license.
With version 1.7.02 my laser can no longer move at the max speed of 6000 mm/min that is set in the firmware anymore.
The engraving and cutting of course are at a slower speed and it works fine, but whenever the motors move the head to another line the motor stutters and makes a bit of a grinding noise and doesn’t move anywhere close to where it should, thus ruining the engraving.
I experimented by setting different max x-axis and y-axis speeds in the firmware through Lightburn, and when I dropped it down to 2000 mm/min it was successful and didn’t have any issues at all.
Is this possibly something wrong the latest version of Lightburn? Could something have happened to the motors while it wasn’t being used at all?
I would definitely like to increase that speed again since larger burns are taking a considerable amount of time now where they didn’t before.
What are your acceleration settings?
Both $120 and $121 are set to 1000.
Upon some additional experimenting, it appears like only the Y-axis is experiencing the issue. I tried homing from various locations, and it will go all the way to the left, all the while the Y motor grinds and doesn’t really move at all. I was able to get a couple successful homings when the head was fairly close to the origin to begin with.
It may be worthwhile to test all the set screws with a hex-key or Allen wrench to confirm that they’re still tight.
They have been known to work loose over time.
Worse yet, “They look tight.”
Another thing worth looking at is that the Gantry might not be square to the frame of the engraver. If it gets off-square it can bind when moving.
If you slowly move the gantry by hand, does it resist or bind up?
It’s important to move slowly because the stepper motor can become a very active generator - moving a stepper motor too quickly can put a voltage spike into the controller even with the power supply off.
Thanks for the suggestions. I just checked all of the screws and they are tight. Also moving the gantry by hand I didn’t notice any spots where it was more difficult to move than others. There’s general resistance pretty much everywhere, but I don’t really know how it’s supposed to feel.
Is it possible the belts themselves could be too tight?
Yes, this is possible and a known cause of binding.
It’s not at the top of the list but it does happen.
If there is no binding I would be looking for any bad connections, check driver current.
Good news. I loosened up the Y-axis belts ever so slightly. They definitely felt really taut before. I performed a dozen homing tests at 6000 mm/min from various locations and they all worked without stuttering.
I guess now I’ll just need to do some regular engravings with normal settings and see how it goes. But for now it’s looking good.
I wonder then, is it possible for the belts to tighten without use, and loosen with use? Definitely something I will keep an eye on.
Possible… I wouldn’t have expected this from a cog-belt. It’s possible that high-volume low-cost cog-belt production has added an “undocumented feature” for us to watch out for.
Greatly appreciated. Thanks for letting us know!