I have a new Sherline 5400 CNC mill. I have written gCode to mill away a section of aluminum from the workpiece, but the limits of what it canb remove are so low that either these Sherlines are just toys, or I am doing something wrong. I am using a 1/4" finish end mill, and it stops if I try to remove 0.01" of 6061 aluminum, attacking it from the edge. Yes, it is oiled. It can cut 0.03" of acetal without trouble, but not being able to cut aluminum (except in .0005" slices) makes this pretty much useless except for learning what I need before buying a REAL CNC mill.