req surface roughness

[fsa]

hello every body
i ahve a question regarding surface roughness on milling operations.

how can we achieve desire roughness thru feed and rpm on milling.for example my req roughness is Ra3.2 now for it what is the feed and rpm for achieve it.

Thanks

fsa

[Algirdas]

maximum revolution minimum feederate. Surface roughness depends on spindle dynamic run-out. For good quality spindle static run-out of 1µm is allowed. Less is better, but difficult to measure. If You have static radial run-out more, than 4µm, forget about clean surface at all.