# Large circle/arc router jig



## vindaloo (May 30, 2009)

I made this jig about 2 years ago for a project but, after building it, I found that it didn't work as intended due to the project, rather than the jig. I got the plans from a shopnotes, can't remember which one.

There is a round disc of ply that you stick to the center of your material, unlock the sliding mechanism, slide to desired diameter and lock it off. The holes in the head part are for my DW625, but there's plenty space to add holes for other routers to the same head. I also made the head detachable so I can use it as a seperate larger base when hand routing.


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## CharleyL (Feb 28, 2009)

Much fancier than mine. I'm sure it will work well. 

Jasper makes several models of router circle cutting jigs which have precision holes in dimensional increments to work well with a 1/4" spiral bit. They are accurate to the dimension picked for the pin, but I prefer the sliding pivot pin like your design because you can make circles or arcs of any dimension that you choose. Great job on the jig.


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## vindaloo (May 30, 2009)

I built it to last Charley, but haven't used it yet! Still, plenty more life in me, touch a lot of wood regularly, so there's sure to be a use down the line.


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## Garyk (Dec 29, 2011)

You must cut a lot of large diameter circles. I usually use a string & pencil to draw the circle then jigsaw the outline and finish the edge with the router. But then I don't need to make that many large circles. Neat concept though.


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## 197761 (May 2, 2017)

That's a pretty cool setup!

I had trouble with the string method when I tried it years ago...either something happened with the pin moving, or the pencil might get hung up on the grain and then the tension of my string would vary for a moment...that was always frustrating for me. lol


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## Garyk (Dec 29, 2011)

DerSchuhmacher said:


> That's a pretty cool setup!
> 
> I had trouble with the string method when I tried it years ago...either something happened with the pin moving, or the pencil might get hung up on the grain and then the tension of my string would vary for a moment...that was always frustrating for me. lol


I'm old John. When I started I was lucky that I could afford the string. I guess you get comfortable with the way you learn to do something.


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## 197761 (May 2, 2017)

Heck Gary,

Even if you can't buy a ball of string, you can always find some! Maybe steal someone's shoe laces?? hahaha If you find a dollar on the ground you can go to the dollar store and at least get some jute!


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## George B. (Oct 30, 2010)

I have a Lewin circle jig for the router. bought it to make a table top for a small table for the wife. If I had to do it again I would buy a circle jig for the band saw instead. The jig is large and you have to make sure you have the waste as well as the circle you are cutting supported and then there is the long grain to end grain transition that can cause tear-out. I think the band saw is a better choice for cutting circles.

George


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## CharleyL (Feb 28, 2009)

Since getting my CRB-7 router jig and the additional diameters of rods for it, I now use it for making all of my large diameter arcs and circle router cuts. The 4 rods are threaded, with one end female and the other end male, so the extra rods can be assembled end to end joining to one of the rods used in the CRB-7. With the circle piece on one end of these rods and the CRB-7 on the other, I can make circles or arcs with a radius up to almost 3'. The CRB-7 jig is now my preferred way of cutting most arcs or circles. I also have several Jasper plastic jigs as well as one shop made one that's similar to the one in the first post. With this assortment of circle jigs I can do any circle or arc cutting that I've needed to do.

Charley


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## 197761 (May 2, 2017)

I just had to look up the CRB7 and that looks really cool. I saw a man make a homemade one similar to that, the way it looked in the end reminded me of a etch-a-sketch. I was like, cool but I can't build that! But this thing you are talking about is NEAT!


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## CharleyL (Feb 28, 2009)

Cindy,

There are several shop made versions of the CRB-7 on this forum, but I don't think any of them can do everything that the CRB-7 can, but keeping all of the pieces of my CRB-7 together quickly became a problem for me, so I designed a box to hold it all together.
This box has been doing a great job and I haven't managed to loose anything yet.

Charley


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## MGildersleeve (Jan 15, 2018)

Rigged three tables to together and made about a 14' radial arm before. It worked out great. I've heard of arms getting a lot longer than that. Always fun to mess around with those things.


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