Die Grinder as a router

I have tested this extensively.
The smallest die grinders of the $6 chinese variety can cut
about .06" to .08" deep with a 1/4" two flute router bit in hard
maple at 50 inches per minute. This is pretty much full load. More
than this is in danger of a stall which equals instant broken bit.
It also depends very much on the pressure drop of air in your
system. If you have a huge compressor like 20CFM or more at 100psi
then you will get more power. The normal pressure drop of a home
shop compressor with a high consumption device like a die grinder
will really sap your power.

To put things in perspective. An air motor with the power of a
normal 1hp electric router would have to have a compressor of about
20 H.P. It depends on lots of things like compressor design but this
is a good rule of thumb.

Pneumatic motors are best for engraving with tiny tools where you
need super high speed and little torque. If you really want to cut
and remove material find a way to get an electric die grinder to fit.

Joe V.