So glad I found this site. My intent is to build an XY laser cutter, for Balsa and hobby ply's. While many questions are arising I have a couple that need addressing to get started. First off, I am divided on using belt or ball screw linear way provided by this site. Both are nice, compact and efficient solutions. Second, how much laser is needed to cut : Balsa wood - 1/8" hobby ply - 1/4" hobby ply - Was hoping that a Blue laser ~ 4-6 watts would be sufficient to handle this work, from an economical standpoint. Surely some are already doing what my intentions are and have some advise from experience.
A diode lase will not cut the plywoods . It will cut the balsa with multiple passes. Your best option is to build or buy a 40W - 60W CO2 laser, there are a couple of good designs here on Openbuilds, as well, a 40W laser can be purchased for around $400 (but expect to do some upgrades to really use it well). Check ouyt the google+ communities https://plus.google.com/u/0/communities/118113483589382049502 and https://plus.google.com/u/0/communities/115879488566665599508. There is a ton of info on those sites. Good luck in your endeavors.
I agree with Anthony, While a diode laser can do the balsa ( and forced to do 1/8 hardi board / plywood ) I do not see 1/4" happening with a reasonable cut time. Check out @Peter Van Der Walt 's 40watt opensource laser Freeburn-2 I am surprised more people do not build one it is a well thought out build. This is 1/8" HardiBoard. Cut using Laserweb 4 and a 2-Watt Blue diode laser from J-tech. This cut required 104 passes at 75% power and a very slow speed..