Cutting tools for balsa routing

Router. I use a porter cable trim router.

Tooling. Router bits of 0.0312 inches are available from:
http://www.drilltechnology.com/

I use diamond cut down cut version. These have a 1/16 inch shaft 
and you have to purchase an adapter from porter cable to accept 
1/16 inch bits in their 1/8 collect. The router bit is what controls
the possible thickness of woods that are cut. I have not seen 
router bits that are around 0.0312 inches with cutting edges greater 
than 1/4 of an inch.

Another site: http://tinkers-emporium.com/newpage31.htm

Alternatives.
I strongly recommend investigation into usage of a
pnuematic drills such as:

http://www.turbocarver.com/
http://www.scm-network.com/powercarver.sot
http://www.mhc-online.com/main/foredom3.htm

or highspeed dental tools such as:

http://www.handpieceparts.com/
http://www.direct-turbine-sales.com/

Highspeed drills are used with good success by egg-carvers, engravers,
and inlay-artists. From what I've gathered so far, they absolutely
sing through wood because they spin so quickly. Wood carvers are fond
of them because of the very low lateral force has to be exerted when
moving the tool through wood. Such drills are pneumatic and will
require a separate source for compressed air.

Another technology to investigate might be hardware that's used for engraving. One suggested web site: http://www.antaresinc.net/
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