Re: Any recommendations for router circle-cutting
Keith L Newton
Howard, What I've done for years, is to rip a scrap of 1/2" plywood about as wide as the base of my router. Then drill a hole of the same size as the router's template guide bushing to insert into. Then set the router down on it, and lock the bit flush with the bottom and roll it onto it's side to measure from either side, whichever your cutting inside or outside, then drill a small hole for the center to rotate around. I never felt a need for any stinking store bought jig with this.
Now, you didn't mention size, so if you want a really large arc where a wooden arm gets cumbersome due to drag and flex, >8', like some years ago when I needed a series of concentric arcs from 30' out to 40' to make nosing for the steps of a church choir loft, I used a 100' steel tape measure. By taking the lower fence portion off the router edge guide, I used the fine adjustment screw hole to attach the hook on the end of the tape, then clamped the measurement I wanted to a porch post out on the back of my parking lot. To keep the tape from snagging, I laid some pvc pipe across so it would slide easily. A waste board under the sheets actually being cut was nailed to the asphalt. That was back in the days before I had a friend with a big CNC router, and even now I might could cut with this set-up as fast as writing the program for the CNC.
Maybe someday someone will stop by and help me do a video of the ellipse jig I made about 30 something years ago.