Transistor wrote:I don't understand the limitations when running a low power device? For example, if 40W would cut 3/8" (10mm) plywood why would a 10W unit not be able to cut it at a lower speed?
That's sort of like asking why you can't bake a cake at 200F or turn it up to 650F and cook it twice as fast.
You can probably cut paper, cardboard, wood veneer, cloth, felt, etc. You could engrave most anything a 40W laser could engrave (possibly slower, but not much on a hobby laser where travel speed is the limiting factor).
The cost of a chinese 40W tube and PSU on eBay is $300-400 total, so you will spend more on the other parts of your machine than the laser. At least design for the 40W tube so you can swap one in later.