ATM circle cutting jig

[Chuck Dethloff <telmor@teleport.com>]

>Can someone tell me the procedure to cut circular woodpieces with a
>handheld router?

Cut a 6" wide by 30" long section of 1/4" plywood and mount it to the base
of your router. For whatever radius you require (limited only by the length
of the board) you can drill holes in it to accept a 1/4 bolt with a bushing
over it. The size of this hole will vary depending upon the style of common
hardware bushing you use. This bushing is helpful because it will not wear
into the wood template like the threads on the bolt would. If you wish, you
can put formica on the bottom side to make it slide over your work surface
easier. That also helps prevent scratches to the wood surface you are
working on. 

Next construct a base out of 3/4" plywood with a 1/4" bolt mounted sticking
up out of the center. This base needs to be large enough to support the
section of wood you which to cut. Then the section of wood that you want to
cut is mounted upon this base. The section to be cut obviously needs to have
a 1/4" hole drilled through it at the center point of the circle or arc that
you want to cut out. After placing this section on the base (usually
attached with a couple small finishing nails)  slide the busing on the bolt
and next the template with attached router. For safety purposes you can
loosely fasten a wing nut on the top of the bolt if you like to hold the
router assembly captive. 

Circle cutting accessories are offered from various companies. I have tried
only one and found it to be more prone to flexure and less likely to cut
accurate circles. Perhaps some of the more expensive models work better. The
above jig can be made of common and inexpensive materials in a couple of
hours or less. It is easy to use and allows for simple reproduction of
different sized circles. 

Chuck Dethloff
telmor@teleport.com