Bandsaw would be my first suggestion

Double stick tape it to a sacrificial piece with a straight edge to give you a guide for a straight cut on the table saw.

After you have a half circle, your miter saw should work

You have that beast of a scrollsaw for your avatar, a #9 blade and a lot of patience could give you good results, with a little sanding to dress the edges if you aren't perfectly straight

 

Kristin, for this project I would use my table saw with a sled. You know the cut will be exactly where the edge of the sled is. Measure the thickness of your saw blade.(Mine is 1/8") Buy a roll of automotive pin stripe tape the same width as your blade and use it to mark your layout on the piece. This way you know exactly where the cut will go with no math.

 

Hi Kristin

Your RAS should will do the job fine ,you don't need to cut the full depth in one pass .two or 3 will do just fine..I would stick/pin nail it down to some 1/4"/? thick plywood for the RAS saw job
Just like cutting a pie but not the crust.(plywood) one side of a pentagon for the plywood base plate..cut it and then turn it and make the others cuts..

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The plywood blades I am familiar with only allow about 1" depth of cut. I warped one trying to cut deeper and making multiple cuts wouldn't have helped because the blade was thicker 1" in from the edge.
I don't think you can use your miter saw as my calculations come up with about 6 3/8 at 45 deg.

 

http://www.amazon.com/Milwaukee-48-...e-ATB-Set-Plywood/dp/B00004WHJQ/ref=sr_1_38?s=hi&ie=UTF8&qid=1324702339&sr=1-38

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Excellent idea for a fixture but I am thinking with the 1/8" kerf now the parts will not fit together properly, perhaps I will have to add a 1/16" lamanate to the sides to correct this.

 

Hi Kristin

Thanks

I don't think you will need to shim up the sides, because you are cutting all the way across the cir., just like cutting a 45 deg. cut on a board or to say cutting it into two parts, the parts will fit back into place just smaller..(shorter)

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I've put a lot of thought into your problem Kristin and I reckon that a sharp knife will solve your "problem"!

 

Hi Harry

" I reckon that a sharp knife will solve your "problem"! " == ????

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