Reading one of Gerry's posts, he gave some info (http://www.cnczone.com/forums/showpost.php?p=139189&postcount=11) that leads me to the following:

Material: Plywood

Tool...|.Radius.|.Depth per pass.|.Speed...|.Spindle
Spiral.|.?........|.19mm..............|10m/min.|.10HP
?.......|.?........|.19mm..............|.3m/min.|...2HP (too low)

Does anyone have further data correlating material, cutter and spindle horsepower to cutting depths and speeds?

What I'm after is a table that allows you to work out sensible depth per pass and cutting speeds for a given material/bit/spindle HP.

Also, the rpm of the cutter would be useful to know - I believe this is something to do with 'chip load'?