Tools and Reviews Routers 3 steps to routing large circles With just a router, a straight bit, and a router trammel, you easily can form large, perfectly circular parts such as this project's tabletop. By WOOD Magazine Staff WOOD Magazine Staff Launched in 1984, WOOD® magazine is the world's most trusted woodworking resource — a distinction we've earned by guaranteeing our readers' success in their woodworking shops. It is the mission of our staff to inspire and inform woodworkers at every stage of their journey by providing reliable and accurate project plans, woodworking techniques, and product reviews. WOOD magazine's Editorial Process Updated on April 2, 2024 With just a router, a straight bit, and a router trammel, you easily can form large, perfectly circular parts such as this project's tabletop. No trammel? Don't worry. In a flash, you can make the one shown in the drawing, below, that will let you cut circles up to 72" in diameter. Here's how to put the setup to work: Insert and fasten the trammel's rods in your router's edge-guide mounting holes. Then, set the radius of the circle by measuring from the inside of the straight bit's cutting edge to the center of the trammel's pivot pin. Now, lock in the radius by tightening the trammel's knobs. Drill a hole, sized to suit the trammel's pivot pin, in the center of the workpiece's bottom. Make the hole at least 1⁄4 " deep but not through the workpiece. Or drill a hole through the scrap pivot block's center, and reattach the block to the tabletop's bottom. With the workpiece rough-cut to within 1⁄8 " of the finished diameter, insert the jig's pivot pin into the drilled hole. Now, plunge the router bit, and slowly rout the workpiece, as shown in the photo, above. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit