Circle router jig BLOG

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Blog entry by mafe posted 02-23-2012 02:22 PM 21947 reads 15 times favorited 11 comments Add to Favorites Watch

Circle router jig
My version.

This is a jig I have seen on the web and here on LJ in several versions, I cooked up my version and added a cheap curtain aluminum T-track so I always can extend to any length simply by buying a longer rod.
(I think originally the design comes from a woodworking magazine).

Since I had the photos and could see the interest on the post I made this mini blog showing more details for those who want to make one.

The layout is a plywood (plywood for concrete forming) base that are the width of your router base and then app double the length, this will provide a stable base.
Place the router in one end of the base and then mark up for mounting screws and fix the router to the base.
Once the router is fixed, route a hole through the base with a small router bit to locate the center of the bit.
Now mark this line up on the base and offset it to make a rabbet for the circle arm / T-track.
Also make two holes in the center line of the rabbet with a distance of app 7,5 cm (3 inch) for the adjustment rabbet.

Drilled the hole for the router bit, with a cup drill (could be done with the router).

Used my mortise jig as a small router table to route the rabbet for the T-track, in the center of the jig.


Then a smaller bit to route the rabbet for the adjustment between the two predrilled holes.

Drill holes in the T-track for each 5 cm (2 inch), since it can be adjusted free on the jig it do not need to be dead accurate.

A piece of wood or ply fitted in the T-track and bolt mounted in it.
This end will go into the adjustment rabbet on the jig and a wing nut or a knurled bolt will be added on top to tighten it once the radius is set.

Here from the other side.

For the end that need to be moved between the holes again a small piece of wood with a hole in the middle, fitted inside the T-track and rounded in the ends for easy slide.
Through this hole you screw or nail into the center of the circle you want to make.

Here from the other side.

Here the parts for the adjustment.

Rounding the base.


Jig mounted with a short hardwood rod I also made.

Making its first circle.
It works excellent!

Short and long arm, it should cover most needs.

And finally from the top while routing.
Notice the knurled nut for the adjustment in the back under the dust hose.

This is the kind of curtain T-track I refer to, but you can use any T-track or a hardwood strip.

Hope this blog could inspire, and that it will be at help for those who wrote they will make one,

Best thoughts,

-- MAD F, the fanatical rhykenologist and vintage architect.

11 comments so far

View TrBlu's profile


386 posts in 3680 days

#1 posted 02-23-2012 02:34 PM

Very nice, Mads!

May have to modify this idea for my PC router.

-- The more I work with wood the more I recognize only God can make something as beautiful as a tree. I hope my humble attempts at this craft do justice by His masterpiece. -- Tim

View patron's profile


13717 posts in 4396 days

#2 posted 02-23-2012 02:51 PM

as usual
straight forward and versatile

well done mads

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

View stefang's profile


17040 posts in 4389 days

#3 posted 02-23-2012 04:33 PM

Hi Mads, I thought I had commented on this one, but I do have this problem of scrolling down to the post button sometimes.

I liked this jig a lot. I’ve seen others similar, but I think yours is the best version. I like the wood ‘shoe’ that is inserted into the aluminum rail to tighten. The details, as in this case make a big difference. Thanks for posting.

-- Mike, an American living in Norway.

View stefang's profile


17040 posts in 4389 days

#4 posted 02-23-2012 04:45 PM


-- Mike, an American living in Norway.

View FirehouseWoodworking's profile


786 posts in 4328 days

#5 posted 02-23-2012 05:32 PM

Another great jig and wonderfully thought out instructional blog. Well done, sir!

But again, only one thing missing! Where’s the pipe in the pictures?!


-- Dave; Lansing, Kansas

View Diggerjacks's profile


2330 posts in 4193 days

#6 posted 02-23-2012 06:34 PM

Hello mafe

Very nice and instructive blog


-- Diggerjack-France ---The only limit is the limit of the mind and the mind has no limit

View SASmith               's profile


1850 posts in 4042 days

#7 posted 02-23-2012 09:30 PM

Great blog.
Thanks for sharing.

-- Scott Smith, Southern Illinois

View BritBoxmaker's profile


4611 posts in 4091 days

#8 posted 02-23-2012 09:35 PM

Nice work, Mads

-- Martyn -- Boxologist, Pattern Juggler and Candyman of the visually challenging.

View fernandoindia's profile


1081 posts in 3998 days

#9 posted 02-24-2012 04:52 AM

Hi Mads, Great job.
Thanks for sharing. I was missing these blogs, :)


-- Back home. Fernando

View lanwater's profile


3113 posts in 3989 days

#10 posted 02-24-2012 05:57 AM

Very detailed blog Mads. It’s always a pleasure reading them.

Thanks for sharing

-- Abbas, Castro Valley, CA

View Jim Jakosh's profile

Jim Jakosh

26065 posts in 4160 days

#11 posted 02-27-2012 05:02 PM

Great jig, Mads. Thanks for sharing your version!!..........Jim

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

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