# Circle cutting fixtures for bench router and Bandsaw



## thegrgyle (Jan 11, 2011)

Well, I know that this circle cutting fixture may seem quite simple, but I have grown to love it. I have made two versions of it, one for my Router table (which is part of my tablesaw), and one for my benchtop bandsaw. 

Here is a pic of the tablesaw/router table set up. First the saw/router table without the fixture…










Now with the fixture installed…..



















Then the jig on the top, screwed down in the four corners… I drilled and tapped ¼ - 20 holes and then recessed the holes in the top for some ¼-20 bolts. I cut a dado to accept a T-track that goes to the center of my Router opening on the TS. I installed a 4’ track, and now have the ability to route out an 94” circle if need be. The largest I have done on this set up was 60” for a friend of mine.

I also made this one for my benchtop bandsaw, and its capacity is only 14.5”, for a total diameter of 29”.









This is a picture of the “pin” that I use in the T-track. It is just a sliding T-nut with a set screw in the middle to lock it down. I just have to drill a 5/16” hole, around 3/16” deep for the “pin” to sit in. It works great!


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## thegrgyle (Jan 11, 2011)

And here is a pic of a piece of MDF that I cut a circle into…. 










I am making another Thein topper for my DC, and this is the first cut in many I will make with this jig.


Hope this helps…..


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## mikeintexas (Oct 25, 2011)

Nice. I need to make something like that for my BS. I dont' have a router table yet. I have a Jasper circle cutting jig for my router but it only cuts up to 18.75" (IIRC) circle. I need more like 20" for the Thein lid. The one I made is too thin on the outside "rim" and is cracking. Thin MDF doesn't hold up too long.

Question: On the BS jig, how do you start the cut? With the router, you just raise the bit up into the workpiece...how's that work with the BS?


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## gus1962 (Jan 9, 2013)

That's really nice! I think I might be needing one in the future for my band saw.


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## thegrgyle (Jan 11, 2011)

mikeintexas said:


> Nice. I need to make something like that for my BS. I dont' have a router table yet. I have a Jasper circle cutting jig for my router but it only cuts up to 18.75" (IIRC) circle. I need more like 20" for the Thein lid. The one I made is too thin on the outside "rim" and is cracking. Thin MDF doesn't hold up too long.
> 
> Question: On the BS jig, how do you start the cut? With the router, you just raise the bit up into the workpiece...how's that work with the BS?


Usually, with either one of them, I measure the middle from one edge, drill the 5/16" hole, and then line the edge I measured from with whichever tool I am going to cut with. With the top that I had pictured, I actually clamped the piece to the top, and "plunged" the router into the piece, then took the clamp off and spun it around to cut the circular groove. It was a little scary, and probably not the best idea, but it worked.

One thing that I forgot to mention with the bandsaw fixture, is that I have a piece of plywood that I use a brace on the t-track when cutting larger circles with that.


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## mikeintexas (Oct 25, 2011)

Thanks for the details. I've been checking out some other BS circle jigs online and noticed most of them have a base of some kind. Need to see how big I can go on my 14" BS...probably 14" I guess, right?:blink: For an overall diameter of 28". Not exactly table-top size, but good enough for a Thein lid.


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## Chris Curl (Jan 1, 2013)

that is the exact same design i have for my circle jig. mine is just a smaller version of yours. i like it very much too.


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## thegrgyle (Jan 11, 2011)

mikeintexas said:


> Thanks for the details. I've been checking out some other BS circle jigs online and noticed most of them have a base of some kind. Need to see how big I can go on my 14" BS...probably 14" I guess, right?:blink: For an overall diameter of 28". Not exactly table-top size, but good enough for a Thein lid.


 
Actually, you cut your circle on the OUTSIDE of you blade, so your circle is only limited to how long your "pin holder" is held in your jig/fixture. So mine are limited to the length of the t-track on each fixture..... 

If I was to do it again, and I still may modify my current fixture, I might incorporate something like this, which I just saw on an episode of the woodsmith shop. This lets you slide the workpiece into the blade, and THEN start cutting the circle. Its actually a really good idea.


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## mikeintexas (Oct 25, 2011)

Thanks for posting those plans, thegrgyle. They look great and easy enough for me to build. Looks like a weekend project! :yes: I really like the Jasper jig for my router, but honestly, it's a PITA to remove the router's bottom plate, mount the Jasper, use the alignment pin, etc. Plus, for smaller circles, the pivot pin hits the router's baseplate and doesn't seat fully, meaning I have to drill a deep hole in the material, use two backer boards, etc. This jig would solve all that. I know what I'm making this weekend. :thumbsup:


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## jharris2 (Jul 9, 2012)

Thanks for posting TG,

I've been wanting to build a trammel type circle cutting jig.

Now I don't have to. My RT is 30"x60". All I need to do is install 
t-track directly into the table top in alignment with the center of the collet.

Very cool!


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