cutting circles on a band saw

[Joe Von Kaenel]

Hello,

I found plans and made a circle cutting jig for my band saw. I measure and mark the radius, then do the same on the wood to be cut. Insert a pin into the jig and put the blank in the pin. I always end up with a flat spot where the cut was started. I am starting with the wood touching the side of the blade. If I move the blank away from the blade the the circle is bigger than I want. Norm makes it look soooo easy.:eek:
Any advice? Thanks


Joe

[Robert Parrish]

I just made a jig last week based loosely on Norms and it works fine. You need to start with the blank cut roughly to size just touching the blade. Make sure the jig is securely fastened to the band saw and doesn't move on you.

[Mike Cutler]

Blade size and tooth configuration will have an impact on circle cutting. What size blade and tooth configuration are you using? Your circle jig should also align the outside of the radius at the front of the teeth. I usually use a 1/4" 6-8tpi blade for circles. It's slower, but the edge is cleaner.

One more" trick" I have used is that my circle jig rides in the right hand miter slot, so I advance the material into the blade and begin my cut when it meets the positive stop I set up.
Whatever you do, do not stop, and try to keep the material turning at the same speed for a better circle.

[Dave Bureau]

i use a jig in my saw with no problems. I use a 1/4" blade.

[Bill Huber]

I am not sure if this is good or bad but it is the way I use my jig and it works just fine.

To start I set my center point about a 1/16 back from the front edge. So If I am cutting a circle that is 12 inches I set the cneter point back 6 1/16 inches. I am using a 1/4 inch blade on my Jet 14 inch saw.

I have the band saw blade guide raised up a little more then normal so when I put the workpiece in the blade can flex that 1/16 of and inch. Turn the band saw on and the blade will cut in that 1/16 of an inch and then I start my cut.

Now I just turn my wood around and make the cut.

[Joe Von Kaenel]

Gents,


I an using a 1/2" blade with 4 teeth per inch. Sounds like it is too wide.

Joe

[Tom Veatch]

...Sounds like it is too wide.

Depends on the cutting radius. Here are links to a couple of charts that show minimum radius for various blade widths. Personally I take charts such as these with a grain of salt, but at least they give an indication of what to expect.

Exerpt from "The Bandsaw Book" (http://books.google.com/books?id=LuQdQ6ML8sAC&pg=PA72&lpg=PA72&dq=band+saw+cutting+radius&source=web&ots=4NZGVA10R6&sig=5X-3mMFpa_qQvrXIT1xBspYXcBE&hl=en&ei=CoWYSYKyDKCYNa_MnfEL&sa=X&oi=book_result&resnum=6&ct=result#PPA73,M1)

Woodworkersguide.com (http://www.woodworkersguide.com/2008/01/23/bandsaw-blade-radius-chart/)

[Alan Tolchinsky]

If you want a perfect circle, use a router with a jig. This gives you a very smooth cut out and all it needs is a very simple jig. I too made a bandsaw circle jig but never used it. At least so far.