It seems whatever settings I choose, my GF just can’t get all the way through. The best I’ve got it barely seeing a scorch mark on the underside of the material (and that’s with a comical amount of charcoal produced).
Sp200/pw80 18passes is where I’m up to now.
My question is: (I’m very new) Is there something obvious I’m missing, outside if speed/power/passes that would result in the maximum depth of cut being limited like this?
A lot of it depends on the material. Not all plywood is created equal.
If you are getting a lot of char, and the cut still isn’t making it through, it could be something in the glue that they use for the plywood or bondo, or air pockets inside. Any of the above will keep the laser from cutting it.
18 passes sounds like air pockets. There’s a primer on how to check your wood with a flashlight here: Trick for inspecting plywood
The thing about charcoal is that it is pure carbon unlike wood that is carbon with hydrogens and water and all sorts of stuff that vaporizes much more readily when hit by a laser than pure carbon that has all that other stuff gone already that only heats up making more of itself.
I use a fair amount of 3/16" (a little under 5mm) underlayment, a type of ply called Lauan from Lowes, in a single pass. Speed 145, power Full (I have a pro). Edges are no worse than with Proofgrade materials and settings.
