Hey guys, been lurking for a while trying to figure out a cnc machine to build or buy. I am wanting to be able to engrave/mill aluminum and plastics mostly. I have read several posts and reports of machines only being able to cut plastic and wood. What determines this? Just the rigidity of the machine? The problem I have heard with cutting aluminum is that it will vibrate and cause the bit to chatter a lot.
The machine that I am leaning towards getting is either a Lumenlab MicRo or M3, or a Fireball V90 (with a little bit more leaning towards the V90). The V90 has the capability of hold a fairly large router, so it seems (in my mind) that it could have a lot of power and if using the right bit, feed rate, correct depth, it could cut and face aluminum no sweat. Is this a correct assumption? I have faced aluminum by hand with a standard Ryobi router and while it didnt look the best (because it was done by hand), it did, indeed, cut about 3/4" into aluminum(taking off very little at a time, of course).
So, thats my question, what part of a machine determines the material it can cut? I know its probably not a black and white answer, but Im just trying to cram more cnc knowledge into my small brain!