# Router Table Circle Cutting Jig



## mbrun (Jan 12, 2020)

I am one that enjoys the making of shop jigs because I know that jigs make the making of parts easier and more accurate. I like the ones that are easy and fast to setup and use.

Recently I have had need to make a variety of different size discs and cutouts. I have used my handheld router and shop make jig recently for each of these. But when i was making the discs, I thought it would be nice if I could make them with even less hassle on the router table. 

So here is my first pass at the jig made from scrap. 



































The jig concept allows for the discs to be cut while wood rests directly on the router table so no bit extension is necessary. It allows for cutting discs of 1/4” thickness or greater, precise cutting of grooves or rabbets and cutting on both sides of bit. Cutting on interior side of bit allows for handling of larger pieces and provides access to bit raising controls on my lift.

I will continue to play with it, find what works, what I like and don’t like and then post here any refinements that may get made along the way.

4 different discs and rabbets so far and I like the way it works. The concept also seems scalable.


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## Stick486 (Jan 4, 2013)

nicely thought out...
you have any plans to add DC???


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## Nickp (Dec 4, 2012)

Very nice and functional...!


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## DesertRatTom (Jul 3, 2012)

Nice jig. I always prefer to move the workpiece instead of the tool. This is a good solution, thanks for sharing it.


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## AndyP73 (May 15, 2020)

Nice work- thanks for sharing! .... and all the pics!


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## Dejure (Jul 27, 2009)

You get our latest genius award. Nice job.


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## Stick486 (Jan 4, 2013)

Dejure said:


> You get our latest genius award. Nice job.


make that two...


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## mbrun (Jan 12, 2020)

Stick486 said:


> nicely thought out...
> you have any plans to add DC???



Nothing above table just yet. My below-table DC system seems like it captured 90+ percent of the dust when I milled the sample discs with the jig. I really have very little dust on the table compared to my pre-DC days and admittedly thrilled with what I have now. There is more to come though.

I am going to start another thread on my recent DC adventure.


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## mbrun (Jan 12, 2020)

A comment I would like to share is about safety.

When I am routing the discs using the following configuration I feel pretty safe turning the blank; reason being that the router bit falls within the slot in the arm. So when turning the blank there is virtually no way for your hands to accidentally impact an exposed bit. Your hand will always come into contact with the arm first and the bit is below the top of the arm.










However, when routing with the disc as in the following photo one could get careless and blood could be drawn. For this reason I am considering a couple of things. 1) Use this position only when routing rabbets and dados (i.e. bit is always lower than the wood being routed and/or 2) creating and using a bit guard that clamps to the edge of the table and extends out over the bit to prevent a hand from touching the bit.










Regardless of which position is use, it is critical that the user be very conscious about the desired/required direction of blank rotation. 


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## roxanne562001 (Feb 5, 2012)

Nice jig thanks for sharing


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## TenGees (Sep 12, 2012)

Great idea, Michael, I gotta keep that jig in mind.


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## Multiwood (Feb 24, 2013)

Good thinking to come up with a jig like that


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## MEBCWD (Jan 14, 2012)

Nice Jig Michael


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## JFPNCM (Dec 13, 2009)

Excellent jig and the warning is appreciated.


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## Bstrom (Jan 2, 2020)

Love the concept - will be making one myself soon. Thanks for such an ‘ingenious’ Idea...


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## Stick486 (Jan 4, 2013)

I wonder..
would spring loaded hinges be good to act as hold downs???


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## Stick486 (Jan 4, 2013)

another thought...
a layer of UHMW tape to the underside of the ''arm'' to reduce friction???...


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## mbrun (Jan 12, 2020)

Stick486 said:


> I wonder..
> would spring loaded hinges be good to act as hold downs???



Hmmmmm? 

That could be a beneficial feature. 

Since posting I have added a thick piece of Velcro to both the vertical and horizontal components so I could keep the horizontal component up and out of the way until I wanted it down. Spring loaded hinges would counteract this. I wonder how both hold up and down could effectively cohabitate.


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## Stick486 (Jan 4, 2013)

mbrun said:


> Hmmmmm?
> 
> That could be a beneficial feature.
> 
> ...


gate type latch or something along those lines???....


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## mbrun (Jan 12, 2020)

Stick486 said:


> another thought...
> a layer of UHMW tape to the underside of the ''arm'' to reduce friction???...



I have found myself pressing down on the arm a bit and yes that creates friction. The UHMW tape would work, as I think sanding and finishing with a coat of poly or shellac, then a good coat of paste wax. Perhaps even HPL on the underside would be good since it is so smooth.

I did some cuts with a thick washer added around pin to reduce contact area between jig and disc and did make a beneficial difference. A built-in friction reducing feature is warranted.


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## mbrun (Jan 12, 2020)

Stick486 said:


> gate type latch or something along those lines???....



Yes, that could be workable. Sounds crazy, but I wonder if a light duty compression gas cylinders that those used on blanket chest and toy chest lids could serve both the hold open and hold down functions. Hmmmmm?


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## Stick486 (Jan 4, 2013)

mbrun said:


> I have found myself pressing down on the arm a bit and yes that creates friction. The UHMW tape would work, as I think sanding and finishing with a coat of poly or shellac, then a good coat of paste wax. Perhaps even HPL on the underside would be good since it is so smooth.
> 
> I did some cuts with a thick washer added around pin to reduce contact area between jig and disc and did make a beneficial difference. A built-in friction reducing feature is warranted.
> 
> ...


thick large diameter Teflon PTFE washer at the pin...
get real exotic and go w/ axial friction bearing....


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## Stick486 (Jan 4, 2013)

mbrun said:


> Hmmmmm?
> 
> That could be a beneficial feature.
> 
> ...


I would think that would collect sawdust and become dysfunctional after a while...


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## mbrun (Jan 12, 2020)

Stick486 said:


> thick large diameter Teflon PTFE washer at the pin...
> get real exotic and go w/ axial friction bearing....



Oh, the possibilities....


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## Stick486 (Jan 4, 2013)

mbrun said:


> Yes, that could be workable. Sounds crazy, but I wonder if a light duty compression gas cylinders that those used on blanket chest and toy chest lids could serve both the hold open and hold down functions. Hmmmmm?
> 
> 
> Sent from my iPad using Tapatalk


expensive and they fail over time w/ constant use....
and would it provide suitable down force???
how about adjustable self closing hinges w/ hold open???
hospitals and many businesses use them...


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## GregLittleWoodworks (Dec 9, 2014)

A hold down clamp just might work


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## mbrun (Jan 12, 2020)

GregLittleWoodworks said:


> A hold down clamp just might work



Are you thinking hold down clamp as the means to keep the horizontal arm in a down position? How do you imagine it being used?


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## Mike_C (Jul 11, 2020)

another cool option is Marius Hornberger's jig

look for "marius hornberger router table circles" youtube

Mike


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## Alan East (Sep 9, 2020)

very nice innovation


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## schmitt32linedrill (Apr 23, 2013)

Great idea. I'm a jig man myself and have piles of them stacked around my shop.


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## jw2170 (Jan 24, 2008)

Since I am no longer sure that these pictures will be available after the update, going to copy some to my HD...

Would be great to make lazy-susans, etc..


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## JOAT (Apr 9, 2010)

Seem to have missed this thread somehow. 

Of course I don't do it this way. Short, really short, version:
Do not try this at home.
I figure out the size of the circle, nothing larger than about 10 inches. So far. Drill a hole in the center for a 1/4" bolt. Put a nut on, have the circle marked, bolt in hand drill. Have a belt sander, vertical, in a stand. Turn the sander on, turn the drill on, then proceed to sand down to the desired circle size. Repeat for different sizes. Yes, it will work - for me at least. I work mainly with 1/2" plywood. Do not try this at home. I take no responsibility for any injuries if you try it. I am NOT recommending you try this - different background, different experiences; what works for me will not necessarily work for you.


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## RainMan 2.0 (May 6, 2014)

Great idea for a circle jig,and I never would have thought of it . I’m loving the idea of moving the fence to change the diameter . 
Are hinges really necessary? I was thinking the jig could have slots on the vertical area on the fence , and two knobs to lock it in place when you raise an lower it , this way you could have a solid piece


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## jj777746 (Jan 17, 2015)

Two knobs in the fence vertical was my thinking also. Brilliant jig..... Jamesjj777746.


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## JOAT (Apr 9, 2010)

mbrun said:


> However, when routing with the disc as in the following photo one could get careless and blood could be drawn. For this reason I am considering a couple of things. 1) Use this position only when routing rabbets and dados (i.e. bit is always lower than the wood being routed and/or 2) creating and using a bit guard that clamps to the edge of the table and extends out over the bit to prevent a hand from touching the bit.


I'd just make a small bridge out of wood, and glue it so it fits over the bit. Something where you would have to stick a finger in on purpose, before you would get bit.


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