Jig for cutting circles on a Band saw.

Don Baer

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When I was making a 32" round table top out of 6/4 maple I made this jig. It is simply a piece of 1/2" plywood with a couple of pieces of scrap fastened on to fit the Table Top of the saw. I drilled holes in it so that I can make tope from 2" to 48". The holes are every 1/2" apart close in and 1" apart further out. I use a pop rivet to hold the piece in place and then just spin away. Works great for making blanks for the lathe too.

Circle 3.jpgCircle Jig 2.jpgCircle Jig 1.jpgCircle Jig 4.jpg
 
A good jig and one of the more frequently used but there is a refinement that helps to cut perfect circles with less prep. The basic version that Don uses is good if you can make one of your edges already equal to the radius you want but the improved version lets you just get straight to cutting circles. I can't post photos because I don't have one as I pretty much never cut circles - but I attach a sketchup which shows roughly how it works.

Basically the addition is a swinging arm and a stop. The workpiece is attached to the swinging arm as Don describes and the the arm is pivoted in until it meets the stop block. At that point the blade has cut through the workpiece but comes to rest at a tangent to the circle that you want to cut. Keeping the swinging arm against the stop block you can then spin the workpiece and cut your perfect circle.

Hopefully somebody who has one of these for rea will chip in and help to explain my poor attempt!
 

Attachments

  • Circle Jig.jpg
    Circle Jig.jpg
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Ian,
The piece to e cut doen't neet to have an edges that is are equal to the radius. If the piece is over sized I put the piece on the jig turn on the saw and slid the whole jig onto the table with the saw running. It works fine.
Good thinking Don - always more than one way to skin a cat!
 
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