Mainly for @AngusMcleod but useful to document anyway.
Wanted to know how well 1/4" and 1/8" balsa wood cut using the 2.8W JTech laser on the X-Carve. Spoiler alert: actually very well
First off the 1/8" sheet I got. It is this one:
I did the classic laser at 25mm above the surface, 0.2mm step down each pass and 15 passes (emulating a spindle). Usual 1.6amps power (about 2W).
Cleanly cut at 500mm/min which I thought might be pushing it. Kept increasing feed speed until the test square (30mm X 30mm with rounded corners) no longer cleanly fell out on lifting the material. That was at 2300mm/min and 2500mm/min required some pressure.
So safe speed for cutting is 2000mm/min which is about five times faster than I thought it would be. This gives a little bit of over cutting that ensures a clean cut.