cutting an arc with a band saw

[Howard]

I want to make a cutting board - using maple this time instead of red oak - and want to cut an arc at the end of it. What is the best way of using the band saw to cut this arc? Isn't there an attachment you can buy to facilitate this type of cut or at least a jig I can make?

[just4funsies]

The jig is nothing more than a rectangular piece of ply with a pin in it at one end, on which you mount the workpiece with a hole at the center of the arc you want to cut. The hole engages the pin in the jig, and allows the workpiece to pivot through the saw. If the arc center does not fall on the workpiece (big arc or small workpiece) you can fix the workpiece to a second piece of ply that is large enough to contain the center point.

[Russianwolf]

You can set up a circle cutting jig. Basically it's just a long board off the side of the BS table with pivot points along it. As you move the workpiece on the pivot point into the blade, you cut the arch or circle.

Just make sure you have your BS set up well, so that you don't have to do alot of cleanup.

The other option is rough cutting it on the BS and using a flush trim bit in the router and a template to finish it.

[LarryG]

Most curved cuts on a bandsaw are made freehand. Usual practice is to mark the desired curve, cut about 1/16" strong, and then work down to the finished curve by other means (flush trim bit on a router, following a template; files and rasps; disc or spindle sander).

But it sounds to me like you want to means to cut an accurate radius. If so, you can rig up a jig similar to a trammel arm for a router ... the workpiece rotates on a small-diameter pin that is set the desired distance from the blade; as you rotate the workpiece around the pin, the blade cuts to the desired radius. You'll likely still need to do some final shaping by hand, however.

FWIW, for a small-size project like a cutting board, I'd use the first method. I'd make a template out of MDF, get it exactly the size and shape I wanted, and use it and a flush-trim router bit to shape the actual workpiece to final size and shape (after cutting it to rough size with my band saw).

[LCHIEN]

you don't say how big an arc, but the way I find best for making rounded ends, corners etc. is to mark the arc with an arc template or an old coffee can cover or something the right size or a compass,
then cut just outside the line with the bandsaw, and follow up with oscillating spindle sander to get a nice smooth curve up to the line you drew. I find I can't cut the bandsaw line that smoothly.