Proper Router Speed

[Richard J Petruso]

How do I figure out the proper router speed so the wood doesn't chip? Is it a matter of just doing some test cuts or is there a rule of thumb to go by? Thank You Rich Petruso

[Mike in Mystic]

I found this in my useful website notes:

Suggested Speeds

0 - 1 inch in dia - 22,000 RPM

1 - 2 inch in dia. - 18,000 RPM

2 - 2.5 inch in dia. - 16,000 RPM

2.5 - 3.5 inch in dia. - 12,000 RPM

At 22,000 RPM the tips of a 3/4" bit travel at 49 MPH, on a 3 1/2" bit they would be travelling over 220 MPH.

As to the issue of chipout, I think bit speed has less to do with that than making sure you backup endgrain cuts or through cuts with a backer board. To get the smoothest finish, use the fastest speed that can be safely used.

I've accidentally run at slow speed (12,000 rpm) with small bits and had horribly rough surfaces, but when I maxed the speed the surface was baby-butt smooth.

Mike

[Mike in Mystic]

here's a better reference regarding tearout:

[Phisherman]

The larger the cutting diameter, the slower the speed. Also, harder materials need a slower speed than lightweight woods. For example, with small bits use 22,000 rpm on pine, maybe 18,000 rpm for walnut.