Balsa is an amazingly versatile wood widely used in hobby making. If you’ve seen it nowhere else you must have seen many model planes flying around that are made from it. So cutting Balsa with a LASER is possibly something we’re all quite likely to want to do with our CNC machines sometime. To that end I’ve tested cutting some 0.8mm thick Balsa with my 5W doide-LASER mounted on my cheap Chinese 1610 CNC, and above is a photo of the results.
I chose a feed rate of 200 mm/min as I find going faster gives better edges to cuts. However, the Balsa burns quite easily leaving thick black lines around the edges. I tested the Balsa with my moisture content meter which said 8%, so the burning doesn’t seem to be due to the wood being overly dry. However, the cuts are quite clean and it seems that a single pass at 100% power is likely to work acceptably for my purposes most of the time. Of course, what happens on the back is just as important, so here’s a photo of that too.
It seems that the back is cleanly cut and the burning at the edges is less noticable than on the front. In fact, I’d say that, where possible, it could be better to cut a mirrored piece, so that the back can be used for visible edges that can be more easily cleaned up with light sanding. But, probably the most important outcome of my test is that thin Balsa is definitely a material that’s suitable for low-power diode-LASER cutting on a CNC.