Instructables

Did you ever need to make a wheel or checkers for your garden checkerboard? With this easy to build circle cutting jig you can go into production in less than an hour!

 
Remove these adsRemove these ads by Signing Up

Step 1: Tools and materials needed

Tools

  • Table Saw
  • Sander or planer
  • Drill and Bits
  • Centerpunch
  • Countersink bit
  • Screwdriver
  • Tape measure
  • Straight edge

Materials

  • Piece of scrap ¾" Plywood or Melamine apx. 18" square
  • Good piece of hardwood (I use red oak from old pallets)
  • Some scrap wood 1"x1"x6"
  • One ¼" x 2" carriage bolt
  • One ¼" Washer
  • One ¼" Wingnut
  • Assorted drywall screws

Step 2: Measure your miter gauge and cut a guide bar

This jig is actually another kind of sled and will ride in the same slot as your miter gauge.

Measure the miter gauge and rip a piece of hardwood to the same width (give or take a few thousanths). Mine is ¾", which is a very common slot size. I used red oak scavenged from pallets for the hardwood. This piece should be at slightly longer than the size of your work surface (which we'll make in the next step). You'll also need another piece about 10" long.

Plane the piece down so it does not protrude above the table top. For me, 3/8" thick was just right. Use a straight edge to make sure it has been planed down enough. Sand off the sharp edges too.

Step 3: Cut the work surface square

Set your rip fence to a convenient dimension and cut your work piece square. Mine was about 18", but that was just the size of the scrap I had. Leave the rip fence in place for now. You can tell the piece is square if you measure across two diagonals and they are the same. If they're not, your rip fence probably needs adjustment. It's really not that critical for this project.

b1tbang3r20 days ago

I've made one of these before to make round chair tops (seats?). Very nice job!

beantown531 month ago

I would make a clap dog to hold the work piece. This would greatly reduce the possibility of an accident.

Marsh (author)  beantown531 month ago

That's not a bad idea and if I ever have another mass production project with it, I'll add it on and update the Ible. I only made this to be able to make my checkers. We love the outdoor checkerboard.

Loetje1 month ago
I agree with charlieCG, looks like a dangerous method to make wheels. I usually make wheels by making a rough circle on de bandsaw. Then I use the disk sander to finish the wheel. For the disk sander I have made a simple jig, to get perfect circles

Please describe this jig for making perfect circles on a bandsaw.

Marsh (author)  noahspurrier1 month ago
My bandsaw also has a 3/4" slot for a miter gauge and this sled fits right on it. It works in exactly the same way on the bandsaw as it does on the table saw. The table saw makes a better circle though because there's no flex in the blade like there is on the bandsaw.
Marsh (author)  Loetje1 month ago
This is a well known and accepted method of cutting circles on a table saw. It dates back decades and my dad';s Monarch Radial arm saw even had a factory attachment that accomplished the exact same thing.
A table saw is a very dangerous machine, but the only way you can get cut on one is by sticking a body part into the blade. Don't do that!
charlieCG Marsh1 month ago

I'm pretty sure no one ever turns their saw on thinking: I'm going to cut some fingers off today. But it happens regardless. I've personally had accidents doing things that seemed completely harmless. Nearly lost my left index.

Old methods that used a pivot point which was located a minimum radius from the blade to prevent kickback. The tighter the circle, the more you have to twist the blade in the workpiece. Twisting the workpiece at all is pretty much asking to get your work kicked back at you. I bet you can't find one the market for a table saw these days for liability reasons. Your method is better, it makes multiple cuts, rather than twisting. If I HAD to cut circles and all I had was a tablesaw, I would probably use a similar method.


People have come up with much better ways of cutting circles, which come out with finished edges. I have cut them safely by hand with routers with success. I made a plate that replaced the base plate on the router, which had an adjustable swing arm with a stylus point on the end. Works Great. Parts come out with smooth curves, without need for too much finish sanding. Now I use a CNC. Hands down the easiest, safest way. But not exactly accessable.

Not trying to troll, just don't want you to loose a finger.
Charlie

Another option is this: http://www.instructables.com/id/How-to-Make-a-Rout...

Or this: http://www.amazon.com/Jasper-200J-Circle-Cutting-P...

But I guess if you didn't have a router or a jigsaw or a bandsaw, this would be a good alternative.

Marsh (author)  JimTheSoundman2 months ago

This actually works much better than a bandsaw or jigsaw, so I would recommend it over either of those alternatives anyway.

charlieCG Marsh2 months ago

I doubt that, having cut quite a few circles, on quite a few machines. Nice jig though, it certainly works. You need a way of clamping the workpiece to the sled after you press it onto the stylus. Then add a handle to your sled. It would make it safer, and you would likely get better results as well.


Table saws are designed for cutting straight lines, and even that, can be dangerous. Doing anything else is really dangerous. I used to love using jigs like this, and use them often. Then I saw what a table saw can do when even the smallest thing goes wrong. I have helped mop up the blood from a table saw accident, its humbling. Be extremely careful.

charlie

Nice job!