Spindle Speeds, Just trying to understand

[LiamN (Liam Newcombe)]

In woods higher cutter RPMs definitely work and the Pro is rigid enough to not have a problem, especially on such a small cutter.

You can use @gmack 's calculator sheet to work out sensible values

Speeds, Feeds, Power, and Force (SFPF) Calculator

Here’s a free Microsoft Excel workbook that facilitates the estimation and logging of CNC machining parameters and performance. The three tabs at the bottom left of the workbook access worksheets showing estimated parameters for a 60,000 RPM HF Spindle, the Makita 0701 Router, and Dewalt DWP611 Router in Shapeoko 3s. The maximum spindle/router speeds were used on each sheet to minimize cutting forces. The same 1/8" 3 flute endmill with 0.25" DOC and 0.005" WOC in 6061-T6 aluminum with ~0.001 …

For slotting in wood I would run that 1/8" at (minimum) 20,000RPM in my spindle, 1,000mm / min feed rate, that’s 0.03mm/tooth, 3mm deep. I’d push it more normally but a full engagement slotting is hard on the cutter and it’s only small.

You can go faster, for MDF no reason not to go to full RPM, just don’t let the feed per tooth go much smaller, you’re just wasting cutter life and making dust then.

You can also probably cut the slot deeper than the 3mm, but I’ve never pushed the 1/8" cutter, I only use it for detail finishing after roughing out with something larger. A 1/4" in the pro should slot at least 10mm deep and be quite happy.