Hi, I’m new in the forum and new to lasers.
Just bought a Sculpfun S9 and noticed that when I cut left to right I get a repeating sine wave pattern. It is definitely a hardware issue.
I have tried tightening the belt and eccentric nut holding the laser head but doesnt seem to fix it.
I tried engraving a line with the nut completely unbolted and the wobble increased a lot.
I then tried to tighten it and it decreased but doesn’t disappear.
I saw someone talking about bad quality of the wheels running in the v slots but havent found much more info.
I’m sure I’m not the only one so how did people fix theirs?
In the picture bottom line is before touching anything, the second one is with the loose eccentric nut, the top 3 with increasingly tight nut. As you can see the oscilation has a constant rate so the wheel theory sounds plausible but the line with the unbolted nut has a higher frequency.
Vertical and curved lines have no noticeable distorsion
Update: it is even worse and happens on smaller non perpendicular lines as well…i cant understand what it could be. Maybe the speed? Is 6000mm/s too much?
It’s essentially impossible for a diode laser, so the machine is running flat out at whatever its top speed might be. You’re seeing mechanical shake in the gantry.
The correct units (select in Edit → Settings) for a diode laser will be mm/minute. However, LightBurn will attempt to convert 6000 mm/s to 360000 mm/min, which is definitely not what you want.
Change the units, set the layer to, say, 3000 mm/minute, then adjust the power to suit.
The machine may still be wobbly, in which case the mechanical checklist will give you plenty of other places to inspect:
