Sunday, I cut my first part out of aluminum. In the end, everything came out great. However, I e-stopped the program early on to edit the code and restart. The reason was that the first plunge at 2.5ipm with a 1/4" 2 flute endmill made the little guy shake violently. I think it was on 2600 rpm.
I changed the code to plunge at .3 ipm and it liked that better. I don't know if I need an endmill that can plunge better, or if I should just learn to program the machine to ramp its way into the material. My cuts were about .060 deep and I cut at 5ipm, with about a .125 stepover. That part seemed to work fine, I actually feel like I was a bit conservative there. Even at .3ipm the plunging seemed to put the most strain on the machine.