The design works for both ABS and PLA. I have not printed with PLA but others here have had good success with it. Also I thought that PLA had less of a tendency to warp. All I can say is that bed leveling is paramount to getting a good print. If the first layer isn't bonded well to the bed it can start to warp. I will restart my print if I don't like the first layer. Better to lose a few minutes then to have the warm warp 2 hours into the print. Using something like this http://www.thingiverse.com/thing:23257http://www.thingiverse.com/thi... doest wonders for leveling the bed. As far as carbon tubes go, I haven't built a quadcopter with them yet but I have used my mounts and spacers in a tricopter build and they work great. I will post it soon.