Power feeders (how fast do you run them ?)

[Ron Ludington]

I know it all depends on the cutter profile and type of wood. So lets say red oak and a 3 wing raised panel cutter. What feed rate would go if trying to do it in 1 pass, and would it change if doing a 2 pass cut.
It seems the faster I feed the better I get (less burning) but It just looks to fast for my comfort level. I have an 8 speed unit, 6.5, 13, 22, 43 ... I dont remember the rest..
I am cormfotable at the 6.5 ft/min speed, but if your going cross grain, it burns. at 22 it looks pretty good. (43 stalls the machine, more than my 3 hp shaper can handle)
What is the accepted feed rate for this type of work ?

[J.R. Rutter]

The other part of the equation is spindle speed. You should slow that down with larger cutters and run the feeder at lower speed. The cutter tips need wood mass to dissipate heat. Thicker shavings soak up more heat.

Start by assuming that you will get a single knife finish - that is, ignore the fact that there are 3 knives on that cutter - pretend there is just one. You are looking for about 25 - 50 knife marks per inch. (A moulder operator is running about 1/2 that.) Now use a combination of spindle speed and feed rate to hit that number.

7,000 rpm / 13 ft per min / 12 in per ft = 45 cuts per in

7,000 rpm / 22 ft per min / 12 in per ft = 27 cuts per in

Personally, I wouldn't run a raised panel cutter faster than that. But if you choose to, stick to the higher feed rate to keep the tips cool:

10,000 / 13 ft per min / 12 in per ft = 64 cuts per in (burning!)

10,000 rpm / 22 ft per min / 12 in per ft = 38 cuts per in

[Ron Ludington]

Excellent advice. I did not know the science behind it. Thats makesit much easier to figure out. Thanks