Thread: Circle Cutting Jig

Just a possible thought, if you put the block that the dowel is connected to on some sort of runner system then had a t-nut in it connected to some threaded rod with a handle it might just be possible to make a version of this that is micro-adjustable

Originally Posted by noodle_snacks

I needed a circle cutting jig that could cut stuff smaller than the baseplate diameter of my router. Looking around the internet i saw existing designs that involved drilling pivot points for a pin or bolt etc, which would work but not without alot of fiddling. Jigs for making bigger circles used a pivot point and two pieces of dowel though the router itself. That got me thinking, and the jig basically uses the dowel method, but with the pivot point put close to the smallest point the router can make for a minimum circle OD of about 25mm or so

The pivot point is a 1/4in hole that fits very snuggly to a 1/4in bolt hot glued through whatever needs a circle in it (probably could be cut off and just glued in if a through hole can't be used.

Down the track i will probably re-build the thing with a perspex base and something more rigid (like aluminium) for the horizontal bars.

Check the archives as someone made such a micro adjustable jig and there was quite a post on it.

Gidday Noodle_Snacks

Might be worthwhile checking out some of Pat Warners ROuter Accessories.......In particular the OffSet SubBases. Looks like they could easily Rout the kind of holes your talking about!!!

http://www.patwarner.com/621_offset.html

REgards Lou

Yeah i needed something that was finely adjustable within a certain range, Originally i was going to buy a jasper jig but i didn't want to spend that much, The offset subbase would have worked but i am not good at drilling holes to 0.2mm accuracy or so

I have several jigs (small, medium, large radii) that simply screw on to the base of my router. They aren't adjustable -- if there isn't a hole already at the radius I want I just drill a new one. First two photos show the one I use most made out of a piece of silky - good for radius 75mm to 300mm or so. Note the nail as the pivot. For small radii (where the nail is under the router base) I use a shorter nail with head cut off. The third photo is my jig for very small circles -- also doubles up as a secondary router base with square sides offset 4 different distances from the router bit.

I have looked at the adjustable jigs, even thought about making one, but there are two problems:

1 ... with my jig I can come back at any time later, find the exact hole I used previously, and cut a circle exactly the same, and
2 ... with wide jigs (most adjustable ones) there is often a problem holding the job - because the opposite not-being-used end of the jig often (in my case, "always") seems to foul on the clamps I am using to hold my job down!

My main jig (the silky oak one) I have been using for at least 5 years and still there is plenty of room to drill more holes. When it wears out I'll make another.

Qw

Originally Posted by QldWoodie

I have several jigs (small, medium, large radii) that simply screw on to the base of my router. They aren't adjustable -- if there isn't a hole already at the radius I want I just drill a new one. First two photos show the one I use most made out of a piece of silky - good for radius 75mm to 300mm or so. Note the nail as the pivot. For small radii (where the nail is under the router base) I use a shorter nail with head cut off. The third photo is my jig for very small circles -- also doubles up as a secondary router base with square sides offset 4 different distances from the router bit.

I have looked at the adjustable jigs, even thought about making one, but there are two problems:

1 ... with my jig I can come back at any time later, find the exact hole I used previously, and cut a circle exactly the same, and
2 ... with wide jigs (most adjustable ones) there is often a problem holding the job - because the opposite not-being-used end of the jig often (in my case, "always") seems to foul on the clamps I am using to hold my job down!

My main jig (the silky oak one) I have been using for at least 5 years and still there is plenty of room to drill more holes. When it wears out I'll make another.

Qw

QW
Any chance of posting basic plans/instuctions for the jigs?