Router Jigs for Circles and Dadoes

By Jerry Seabaugh

Creating a Double Duty Trim Router JigTrim routers are great for small operations. I wanted to make some precisely fitting holes for flower pots, but the circle cutting jig for my full-size router was too big. So I decided to make a small version for my trim router. Additionally, I wasn’t thrilled about the fence that came with my trim router, and wanted something that worked better.

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Creating a Double Duty Trim Router JigHow about a router jig that had both a circle cutter and an adjustable fence for dadoes, grooves and flutings? This is what I came up with, and how to make it.

Creating a Double Duty Trim Router JigStart with a piece of good 1/2″ plywood. Make the base 7″ x 18″ with an over-size 1/4″ slot cut down the center to accept a T-bolt. Add two guides 1″ X 12-1/2″, spaced 3″ apart.

Creating a Double Duty Trim Router JigMount the router base centered side to side and 3″ from the front edge of the jig base and cut a hole for the bits to go through.

Creating a Double Duty Trim Router JigThe circle cutter pivot pin is a 1/8″ x 1-1/4″ machine bolt, double-nutted with a star washer mounted in a 3″ x 7″ block. I positioned the bolt 1″ back from the front edge.

Creating a Double Duty Trim Router JigThe pivot bolt is held in place with a counter sunk nut on the bottom. You also need to drill a 1/4″ hole 3″ back from the front edge to receive a 1/4″ T-bolt.

Creating a Double Duty Trim Router JigThe under side of the jig base is slotted to receive a 1/4″ x 1-1/2″ T bolt. Note that the bolts for the router base also must be counter sunk.

Creating a Double Duty Trim Router JigThe sliding fence is 7″ x 7″ and the sides are 1″ x 7″ so the fence will wrap around the jig base. Also note the oversize slot to receive the T bolt.

Creating a Double Duty Trim Router JigHere is a top view of the circle cutter pivot pin block installed on the jig base.

Creating a Double Duty Trim Router JigThe view from the under side shows how easy it is to set a radius to cut a circle.

Creating a Double Duty Trim Router JigThis shows the under side of the jig with the fence installed instead of the pivot pin.

Creating a Double Duty Trim Router JigSee how easy it is to set the placement of the fence for dadoes, grooves or flutes.

Creating a Double Duty Trim Router JigThe fence and the pivot block can both be mounted on the base for storage. A great way to make sure all the parts are there when you need them.

Photos By Author

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8 Responses to “Router Jigs for Circles and Dadoes”

  1. Jack Aubin

    That is a good jig, I love it!

  2. Alex

    like working with a router

  3. Ken Cox

    Yes I made some thing similar many years ago for my larger router, make wheels, circle cutting up to 48", works great

  4. Trevor Neal

    Great idea

  5. Bill Roberts

    looks like a real helper

  6. peterolding

    Hi, where are the pdf plans for this jig to download it looks good

  7. Dean

    why can't I see the trim router jig videos or plans. I am a gold member

  8. Chris

    Sorry to sound so ignorant but I just got a trim router recently and I am a relative newbie to woodworking. i just made a project for my wife where I cut dadoes in the base board. I clamped a board to my base board so that I would have a guide. This sounds like a good jig but I don't understand how it works. Couldn't there be more photos or a video of the jig actually being used?