I agree that it's possible to build a machine from (in my case) MDF and have a lot of fun with it, as well as doing some useful work. You just have to accept a lot of limitations in cutting speed, depth of cut, and so on. Great learning platform, though. Out of interest, what did you use as leadscrews? My machine is based on something like M10 threaded rod, which limits max speed on the X axis to about 900mm/min before the leadscrew starts whipping excessively.