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Cutting Large Circles
Sshado:
How do you cut large circles? I need to cut a 10" circle out of 3/4" Oak Plywood and I am wondering if there is anything better than a Jigsaw for this.
Thanks,
Sshado
Veto:
really big drill bit?
Pixelhugger:
I believe you can use a router with a circle jig. Never done it/seen it myself. :-\
RandyT:
Some routers have a circle cutting jig, or at least a way to use one.
This usually consists of a metal rod with a right angle bend on one end, and the means of clamping the other end to the base of your router.
You then drill a hole that is the same size as the rod diameter at the center of where you want your circle. Then attach the rod to the router base so that the inside edge of the bit is at the radius of the dimension you want, if you are after the disc.
*edit* If you are making a hole, measure to the outside edge of the bit.
Then just spin it around and cut it out.
A word of caution: Make sure you have a waster board underneath and your rod goes into that as well. Otherwise, as you finish your cut, there will be nothing to hold the rod and your cut will get ugly. :)
RandyT
Wienerdog:
You can also build a router jig out of pegboard or hardboard.
Cut a scrap piece of pegboard (or any wood for that matter, pegboard just has some holes already. If you use hardboard, you can drill your own hole) into a 5" x 3' piece. In your case, you would only need a piece about 12" long, since the center of your circle will be 5" from the router bit.
Remove the base plate of your router, and screw the wood to the router using countersunk screws. You will have to cut an opening for your router bit to fit through. Now just measure the desired distance from the router bit and drill a hole at the centerpoint of your circle. If your really wanted a 10" wooden disc, then measure 5" from the inside of the router bit, if you wanted a 10" hole, then measure from the outside of the router bit :).
Opps, I should mention that this process is easier with a plunge router. I've done it with a fixed base router, but it is tricky to start the cut...