How to Use a Circle Making Jig for Perfect Circles
By Infinity Cutting Tools | Premium Woodworking Tools ... | Published: 2026-10-24
Category: How-to Guides
Learn how to use a circle making jig to cut precise circles with your router. Step-by-step guide for perfect woodworking circles every time.
Quick answer
Set up your circle making jig on the router base, adjust the pivot pin to the desired radius, and make multiple light passes to cut a clean circle.
Why use a dedicated jig instead of a freehand approach?
A circle making jig locks the router into a fixed radius, eliminating the wobble and drift that happen when you try to trace a circle freehand. The result is a perfectly round cut every time, with consistent depth and clean edges. The Jasper Pro Circle Making Jig, for instance, is CNC machined from polycarbonate plastic, so it stays rigid and won't flex under the router's weight.
Step-by-step guide
- Attach the jig to your router: Remove the router's sub-base and screw the jig's mounting plate onto the router base. Make sure the screws are snug but not over-tightened to avoid stripping the plastic. Check that the jig is centered on the router base before tightening fully.
- Set the pivot pin distance: Measure the desired radius (half the circle diameter) from the pivot pin to the cutting edge of the router bit. Adjust the jig's sliding arm so the pin sits at that exact distance and lock it in place. A common mistake is measuring from the center of the bit instead of the cutting edge. Always measure from the cutting edge.
- Secure the pivot pin to the workpiece: Place the workpiece on a sacrificial backer board. Press the pivot pin into the center point of your circle. If the pin has a threaded tip, you can screw it into the backer board for extra stability. Make sure the pin is firmly planted. If it shifts mid-cut, the circle will be off-center.
- Set the router bit depth: Lower the router bit so it cuts about 1/8" deep for the first pass. Deeper cuts can overload the router and cause burning or tear-out. For thick material, plan 3-4 shallow passes rather than one deep cut.
- Make the cut: Start the router, let it reach full speed, then slowly guide it clockwise around the pivot pin. Keep even pressure and let the bit do the work. Stop the router after completing one full revolution. Pushing too fast can cause the bit to grab and leave a rough edge. A steady, moderate feed rate gives the cleanest cut.
- Repeat for final depth: Lower the bit by another 1/8" and make another pass. Continue until you reach the full depth of the material. For through-cuts, the final pass should just kiss the backer board. If you cut all the way through on the first pass, the workpiece can lift or splinter. Shallow passes prevent this.
Product facts
- Jasper Pro Circle Making Jigs: The Jasper Pro Circle Making Jig is CNC machined from virtually unbreakable polycarbonate plastic and can make 256 different circle sizes from 2-1/4" to 18-3/16" in diameter in 1/16" increments when using a 1/4" straight router bit. This means you can dial in almost any speaker hole or decorative circle without needing a template or compass for each size.
Jasper Pro Circle Making Jigs
