I am currently building a cnc router/mill which will be similar to the c beam bigmouth. I have 1 or 2 operations that will require 5-6 inches of height on the Z axis. One of the operations requires milling a rectangular pocket in an aluminum billet that is about .75 " X 2.5 " X 1.25 " deep. I already have a couple Bosch Colt routers and a Dewalt 611 with 1/4 and 1/8 inch precision collets . One of my questions is will the dewalt 611 be adequate for milling an aluminum pocket or will I need to get a spindle with a VFD. What I really need to know is will I be able to get the correct spindle speed with one of the routers I already have. Just got into this hobby and my brain is experiencing info overload.