Problems will occur if your speeds are too low or too fast for the given tool geometry and material, so it's not advisable to start very low and "sneak up on the ideal" like you might try when laser cutting. The proper combination of spindle speed and feedrate is especially difficult to dial in if you just guess around, costing you tons of time and material...
We are collecting our experiences with different settings in this wiki, and some machine or bit manufacturers also publish tried & tested values that might make your life easier.
Keep in mind that other people's experience with different machines or endmills/bits is always just a starting point to dial in your setup!
Interesting resources for our WorkBee:
- settings for 1/4", 3-flute spiral upcut end mills by Carbide 3D
Feeds and Speeds Calculators
Manufacturers of quality endmills usually supply the tool properties you'll need to calculate the proper speeds and feeds with a couple of formulas. This PDF by Sorotec (DE) explains it nicely.
Of course there is also software that can do this for you (please share your experience):
- cnccookbook: "G-Wizard" calculators
- commercial software - free trials for 30 days, hobbyist version costs approx. $80
- online calculator only comes with values for metals
- "Feed and Speed wizard" web app
- seems like a neat tool for a metal mill but the spindle speeds (rpm) are too low for a CNC router
- kennametal.com web app
- also mostly useful for metal milling(?) - you'll need to know a thing or two about the required input parameters like "SFM" or "IPR" (depend on your material)