Newbie; Feedrate on CNC 6040 and layer thickness

Yes, on a machine with limited stiffness, taking shallow cuts at higher feedrates should work, then one final pass to finish the surface at the full depth. Keeping the feedrate up prevents local heating of the work, which leads to disaster when the aluminum gets soft.

This WILL wear your tools faster, but that is the price you pay on a lightweight machine. Cobalt or solid carbide tools help on the wear situation.

Jon

Ok, thanks for the information :-)

Is there any rule of thumb of drill size, drill RPM and corresponding feed rate for aluminium (and other materials)

And perhaps a good book for a novice or a link?

Cheers

Klaus

I'm still confused by your combination of milling and drill bits. You do not do milling with drill bits, you use milling cutters for that. They have totally different side relief than a drill bit. If drilling dry, you have the problem of work heating, but peck drilling may help.

There is both DEPTH of cut and WIDTH of cut. These are separate parameters. If cutting into a plate of material, the step-over from the last pass would be the DEPTH, and the plunge in Z would be the width of the cut. For the first cut, you have no choice but to cut the full diameter of the cutter when making a slot. Unless using VERY small tools, you'd never take as light a cut as .2mm, I'd maybe do a full mm or even more each pass. I work in inch units, and usually do about .050" side depth of cut and .050" Z plunge, with a 1/8" end mill. I generally run that at

2800 RPM and plow the full cutter diameter at 5 or more IPM, and then make side-cut only passes at 15 IPM or so. Then, I usually leave .010" for a clean-up pass.

Jon