Hey there everyone!
So I've just finished building a DIY CNC machine (Root 3 CNC with a 2.2kw spindle)
I think I'm getting the hang of things now and familiarising myself with feeds & speeds for various end mills and stock.
I understand the reason the tool removing the optimum sized chips and tuning the feeds and speed to achieve a target chip load etc.
E.g after lots of reading and multiple tests, I've settled on this for a 2 flute 6mm compression bit, cutting 6mm ply.
HOZLY 6 * 22 * 50L Compression bit (Tungsten Cobalt + DLC)
2 passes @ 3.5mm DOC per pass
13000 RPM 1040 mm/m
That works fine and all, and it doesn't tear the top or bottom due to the compression bit, but it doesn't really give a nice precision edge.
However, if leave 0.5mm on the roughing passes, and then come back and take off that last 0.5mm with a finishing pass with say 20,000 RPM at 500mm/m it makes the cuts look so much nicer. Damn nice actually, considering it's a machine made from mostly 3D printed parts and skateboard bearings.
So my question is, with the stepover only being 0.5mm on a 6mm diameter bit for this finishing pass, can I disregard these commonly stated chipload equations and go slow with a high RPM and make a bit of fine dust just for the finishing pass?
Thanks!