# routing inside circles



## jimair1548 (Jan 1, 2011)

I am attempting to cut a 6" circle in a 10" disk, as a step toward making a banjo. It consists of (3),1" inch layers of oak to form the "pot" and will have a "skin over the 6 inch hole. I managed to cut the 10" disks with a sled on a table saw, but that method will not work on the 6" inside hole. I have a table mounted router and smaller hand held one. Any suggestions, as to a inexpensive solution would be great. Thanks.......Jim


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## jw2170 (Jan 24, 2008)

jimair1548 said:


> I am attempting to cut a 6" circle in a 10" disk, as a step toward making a banjo. It consists of (3),1" inch layers of oak to form the "pot" and will have a "skin over the 6 inch hole. I managed to cut the 10" disks with a sled on a table saw, but that method will not work on the 6" inside hole. I have a table mounted router and smaller hand held one. Any suggestions, as to a inexpensive solution would be great. Thanks.......Jim


Greetings Jim and welcome to the router forum. 

Thank you for joining us


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## Dr.Zook (Sep 10, 2004)

Hello Jim and welcome to the RouterForums.


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## xplorx4 (Dec 1, 2008)

Greetings Jim and welcome to the router forum. Thank you for joining us, and remember to have fun, build well and above all be safe.


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## jlord (Nov 16, 2009)

jimair1548 said:


> I am attempting to cut a 6" circle in a 10" disk, as a step toward making a banjo. It consists of (3),1" inch layers of oak to form the "pot" and will have a "skin over the 6 inch hole. I managed to cut the 10" disks with a sled on a table saw, but that method will not work on the 6" inside hole. I have a table mounted router and smaller hand held one. Any suggestions, as to a inexpensive solution would be great. Thanks.......Jim


Hi Jim,
Make a simple trammel out of 1/4" mdf to fit your hand held router. I would route these out on top of some scrap ply so you don't ruin a good table top. Find the center of your 10" disk. Put a couple strips of 2 sided carpet tape down so your pieces will not move in relation to each other when routed out. 

Your trammel arm could be as simple as a piece of 1/4" mdf 6" by 12". Draw a center line down the center of the mdf lengthwise. Use the router base plate for the hole pattern on one end. Drill a hole in the center of the base plate pattern larger than the pattern bit for clearance. Mount the mdf in place of the base plate using the original screws (may have to counter sink screw holes). 

Measure from the far side of the bits cutting edge down the center line you drew & put a finish nail for a pivot point at 3". This will give you an inside diameter of 6". Tap nail pivot point into center of 10" disk (you don't have to nail it home just deep enough to hold as you route). Make a couple of passes lowering the bit with each pass until through. If you don't have a plunge router & are using a fixed base router just hold it up so bit does not rest on material when stared, then lower into material with router running. I've used this down & dirty method many times. Here is a crewed drawing hope it helps.

Freud Double Flute Straight Bits - Rockler Woodworking Tools


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## harrysin (Jan 15, 2007)

jimair1548 said:


> I am attempting to cut a 6" circle in a 10" disk, as a step toward making a banjo. It consists of (3),1" inch layers of oak to form the "pot" and will have a "skin over the 6 inch hole. I managed to cut the 10" disks with a sled on a table saw, but that method will not work on the 6" inside hole. I have a table mounted router and smaller hand held one. Any suggestions, as to a inexpensive solution would be great. Thanks.......Jim


Jim, these shots pulled from posted projects might give you ideas. The simply made circle jig is probably the easiest method but if many IDENTICAL ones are to be made then the template and template guide is the way to go. To calculate the diameter of the hole in the template, the simple formula is: guide dia. - cutter dia. + 6", so, if you uses a 1" guide and a 1/4" cutter we have 1"-0.25"+6"=a 6.75" hole in the template. Any questions, fire away.


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## Mike Wingate (Apr 26, 2009)

I would make a circle template with the router using a trammel or a circle jig, or on the wood lathe, then cut with a template guide. The circle template will cut a variety of sizes dependant upon what sized guides and bits that you have. They come in useful to make smaller templates at a later stage.


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## outrigger (Jan 1, 2011)

Thanks Harry. I like the center photo on the top row. I'm making a cyclone dust seperator and that jig will work perfecr for cutting out circle for top of paint bucket to mount cyclone on for support.
Outrigger Alias Dano "Some times a photo is all it takes to make life a lot clearer."


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## Mike Wingate (Apr 26, 2009)

I always mark NESW Centre Lines on my templates before cutting them, then I can match them to centre lines that I have marked on the project to be routed for increased accuracy. Very useful for ellipses.


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## jimair1548 (Jan 1, 2011)

Thanks guys!!! I really appreciate the ideas. I had forgotten that years ago I made a template for a project and fastened it to the router in place of the base plate. Made it from a piece of clear 1/4" lexan. Lost track of it in a move, so may try this from the same material. thanks again for all of the quick responses.....Jim


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## jlord (Nov 16, 2009)

jimair1548 said:


> Thanks guys!!! I really appreciate the ideas. I had forgotten that years ago I made a template for a project and fastened it to the router in place of the base plate. Made it from a piece of clear 1/4" lexan. Lost track of it in a move, so may try this from the same material. thanks again for all of the quick responses.....Jim


That will work.


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## harrysin (Jan 15, 2007)

""Some times a photo is all it takes to make life a lot clearer.""

That is exactly what I think, hence the fact that I wear out cameras like some people wear out cars.


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## jimair1548 (Jan 1, 2011)

Could someone tell me how I can attach 2 or 3 pics to a posting like this?? The pics are currently in my documents file. Thanks ahead of time.....Jim


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## gav (Oct 12, 2009)

jimair1548 said:


> Could someone tell me how I can attach 2 or 3 pics to a posting like this?? The pics are currently in my documents file. Thanks ahead of time.....Jim


You'll find all the info you need at this link
http://www.routerforums.com/starting-off/10373-attaching-thumb-nails.html


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