Circle Jig...

[David Raehn]

I'm cheap but inventive.... I was considering a circle jig for my upcoming build and decided to try an idea:
I have a entry-level router table from a yard sale ($4), a 1/4" straight bit ($3) and some assorted hardware and scrap off of the shop floor($0).

Using a 2' x 6" piece of 3/8 plywood, I drilled a 3/16" hole near one end in which to thread a 1" long 1/4-20 bolt with a 3/4" diameter washer under the head. This slides in the 3/4" slot in the router table and acts as the center. Slide it back and forth to set the inner or outer diameter for the circle and clamp one end to hold it still.

My first attempt yielded a clean cut circle with no runout, and accurate to less than a 32nd.
http://www.guitarpcb.com/apps/photos/ph ... =183541036

[MissileCrisis]

The jig I have is like the kreg jig for cutting circles but it has holes in it big enough to use a drill but to pivot the router around. By the way it's a piece of scrap wood I found that is roughly 1/4 inch thick. I do all my circles that way and now I have like 10 custom (to the 1/100 of an inch) sized holes for the speakers I've built. Works like a charm and allows you customization beyond standard size which we all know are never ideal for real life speakers (they are always a little off of an even value).

[Israel]

a piece of 1/8th aluminum ( from a road sign) worth every mile i ran when i stole it

[Bas Gooiker]

a piece of 1/8th aluminum ( from a road sign) worth every mile i ran when i stole it

Clever way of getting materials, and as a tax payer you where already the owner of the sign in some way anyways.

[Keryn O'Shea]

worth every mile i ran when i stole it

[Israel]

i was 17 then , i have repaid it thousands of times with my taxes since

[88h88]

You should've seen my face when I realised the $200 router I bought had no circle jig with it. I toyed with the idea of buying the official one at a further $50 but looking around the garage noticed I had some stuff I could work with quite nicely.

End result:



For all intents and purposes it's perfect. Ghetto as hell but solid. If it breaks I spend 10 minutes making a new one. And yes there's a wee pencil holder for drawing circles too.

[Harley]

End result:

Very inventive! I like the idea of having the pencil hole.

[Steven Gustafson]

Now just build yourself a base to mount your router to. Find the mounting holes on the router, mark the holes onto the sliding part of the jig, then rout out an area for the bit to go through and clear some extra to allow for dust escape.