I made this jig to help me cut several circles for my friend’s
SCUBA tank holder.
I needed a way to cut the same-sized circular holes through
several pieces of wood.
This is really more of a pattern than a jig, I guess.
It’s just a piece of poplar with a 4” diameter hole in the center.
I just clamp this down over the workpiece and then use a plunge router
with a bearing-bit to cut out the circular hole. The bearing on the router
bit rides along the inner edge of the circle in the pattern. The cutter,
which is even with the bearing, then cuts away a perfect 4” diameter circle in
Since the circles I was cutting went all the way through the wood, I
had to prop the workpiece up off of the table somehow. I removed my
stationary router from my router table and that gave me about a 10” by 12”
hole to work over. I just clamped the workpiece and this jig/pattern to the
router table and cut away. I cut 10 circular holes in very little time.