# Routing Bullnose on Inside of a Circle



## domjdmba (Jan 26, 2014)

I'm trying to make a set of wooden gymnastics rings. The inner diameter is 8". The thickness of the stock is 1 1/4". 

I have a 5/8 bearing guided roundover bit; however, I find that my reference edge is removed by the first pass, so that when I flip the piece over to rout the opposite edge, the second pass cuts too deeply. If I lower the bit (so as to keep the reference edge intact), then I don't get a true circle profile, but rather a flat spot along the centerline. 

I also have a 1 1/4" bullnose bit that will cut the entire round profile in a single pass. This eliminates the flat spot or vanishing reference edge problems, above. The bullnose bit does not have a bearing to guide it, so I use the router table fence the rout the outside edge. Any suggestions as to how to rout the_ inside _of the circle using the bullnose bit? I was thinking a round fence that matches the inside diameter of the circle with bullnose bit positioned through a hole in the circular fence so that the cutting edge protrudes a hair past the edge of the circular fence. Any suggestions would be most welcome. Thanks!


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## jw2170 (Jan 24, 2008)

Welcome to the forum

I would cut a circle template and use the round-over cutter with a guide bush.


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## Gaffboat (Mar 11, 2012)

jw2170 said:


> welcome to the forum
> 
> i would cut a circle template and use the round-over cutter with a guide bush.


+1


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## Semipro (Mar 22, 2013)

Hello and welcome to the router forums Community.

I have use the round over bit for one side and put a little larger bearing on and route the other side not perfect but will sand to round


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## old55 (Aug 11, 2013)

Welcome to the forum.


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## Cherryville Chuck (Sep 28, 2010)

Another option is to put a bearing on the shaft of the bullnose bit with a lock collar to hold it in place. Then you can attach a circle template to the ring. It would be nice to find a bearing that is the diameter of the bit in the centre of the concave but you can adjust the size of the template to make up for one that isn't the right size.


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## neville9999 (Jul 22, 2010)

Mr. n/a, a name would be nice, You did not say what these rings that you will make will be used for. So will they hold the weight of an athlete? If they do then are you sure that you can make these rings out of wood and they won't collapse when some gymnast is swinging giant circles and upside down? If these home made rings break then so does someones back, or have I missed something about the rings you intend to make? If these rings will hold an athletes weight and you do not know how to do that so they will never break then this is one of those times that you buy ones that come with manufacturers warrantee, someone who has insurance concerning rings breaking. NGM


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## Wildwood (Aug 14, 2010)

Further to Neville's comment, if you are using a single solid piece of wood, you will have 2 weak spots, where the short grain is exposed - to overcome this you should laminate 2 pieces of wood with their grain directions at right angles.


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## 64 ford (Apr 21, 2013)

This looks like a potential liability issue as well as not wanting someone to get badly injured.
If you do this any of the ways described should work. Perhaps,laminated Birch plywood or something similar would be safer.
Dennis


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## Cherryville Chuck (Sep 28, 2010)

I've gone back and reread your post DOMDJMBA and it appears you intend to make them from one solid piece of wood. Read Neville's post carefully and then forget about making your own rings.


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## OPG3 (Jan 9, 2011)

My mother bought some wooden towel rings - they looked nice and they broke. When the towel fell - it was no big deal. There are companies that make these things for a business, send them money - it will be much cheaper than a trip to the hospital.


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## domjdmba (Jan 26, 2014)

The rings are for my own use, and they are made out of laminated baltic birch. Thank you for the concern and helpful comments.


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## beemor (Feb 29, 2012)

If I remember correctly (a rare occasion) the rings used back in the 50's were wooden. Laminated and ?maybe?? with an inner metal ring for strength. Most gymnasts are slight of build but it's the "jolt" some moves generate you have to worry about. I would be interested in seeing what you do.


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## Dejure (Jul 27, 2009)

+2


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## Dejure (Jul 27, 2009)

If I was going to make something like this, I think I'd do everything I could to reinforce them. For example, I'd laminate thin pieces to so vertical grain countered horizontal grain. Maybe as much as four layers, if possible.


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## OldEd (Feb 4, 2014)

*how to route an exercise ring...*

Chuck up your 1-1/4" bit and use a guide bush in a template with a suitably sized hole in it to guide you.

You place the template *ABOVE* the object to be routed, of course, and the two must share the same center line.


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