Circle Jig on the Bandsaw
George VondriskaGeorge Vondriska shows his shop-made circle jig solution for cutting a perfect circle on a band saw. A WoodWorkers Guild of America original video.
I've got a project I'm working on. It's a table and I've got a kind of big round top. So I wanna take a second and show you the circle cutter that I would use to cut a perfect circle every time. Made this myself, so it's a shop made circle cutter. Got a couple of things going for it here.
Now look at the bottom of it, here on the bottom. There's a cleat. This cleat is gonna end up up against the edge here on my bandsaw a table, Another cleat back here. This one has got a threaded NAB into it. When I tighten this NAB it tightens against the dovetail slider.
I'm gonna show you in just a second. So obviously the cleats are also helping to hold the two halves of the jig together. Now this dovetailed slider is here. So the end is actually cut in a dovetail shape. When I loosened the NAB in this cleat, I can slide this back and forth that lets me adjust for different radii.
So when this goes onto my bandsaw it slips over the table and remember that cleat hits the table. So it's up against it there. I'm gonna slide my pivot point as close as I can to the blade. And then look down through here to eye it up. What I wanna do is get the center of the pivot point at the very front of the bandsaw blade.
In order for this to work correctly. Then I can reach under here and lock that cleat right to the bottom of my bandsaw table and we should be set. I'll do a test cut first just to make sure it's cutting a circle correctly. If your front to back adjustment is just a little bit off then the circle is not gonna cut perfectly. So sometimes you're gonna need to do a test cut.
Tweak this position just a little bit and then correct it before you go onto the real circle. In order to make a cut. I need to drill a hole in my piece. That'll sit on that pivot point right there. So I've got a 1/4 inch hole matches the 1/4 inch dowel.
This is what I use when I do larger circles like this. On smaller diameter circles on this end of the jig I've just got a screw tip poking through and you can rush small circles on that. But I find that in bigger circles it's better to use the 1/4 inch dowel and a 1/4 inch hole, it engages better. So they're not likely to jump off the circle cutter on you. So I'm gonna get that in position.
Get it close to the blade. It's not pushed right up against the blade. Lock this down and we'll see how this test cut goes. That worked out great circle cut very well. Like I said, sometimes you have to make small adjustments in the circle cutter position to get it to cut just right.
Once this is correctly set, I can slide this to any position I want in order to make the final cut. So now I'm ready to actually do that big tabletop I was talking about. I've got the hole drilled in the bottom of my tabletop. I've done one other thing to get started. I've cut a notch here.
That's so that when I start making my circle when I first start cutting there's a spot here for the blade to sit inside. Instead of starting out here on the outside of my material, this way, I'll get a perfectly round circle. So all I need to do now is get the dowel seated into that center point. This is the hardest part of the whole process. Just finding that hole.
Then I can gently bring the slider in. That notch is gonna completely capture the blade. Now the diameter of my circle is determined by the distance from my pivot point here someplace to the bottom of that notch. So that would be the radius. And of course, two times that would be the diameter.
So we're all set to go here, get this tabletop, cut out. There we go, we got a perfect circle. Much easier than using a compass and drawing a circle and trying to do it freehand. I've used the shop made circle cutting jig for everything from table tops to bowl blanks. It works great.
Hope it works well for you too.
It would be good to know what machine and blade size your using
What keeps the sliding circle center positioner from dropping out from the underside of the jig?
Is it possible to get the drawings and dimensions for constructing the circle jig for the bandsaw? Thanks
Excellent jig. I have one I made myself but it doesn't work well. This video showed me what I was doing wrong. I'm just going to use your idea and build me a new one. Thanks
Where do you get the plans for this jig
Is there a plan or dimensions available for this?
Do you lock the Slider when cutting the circle?
Outstanding idea. Any possibility to have a copy of the plan. And the one for the route as a player.
Is there any way to have a copy of the plan for me to built one for my small Craftsman band saw. I will be appreciated. It is a great idea.
I like to keep a wide blade in my bandsaw for resawing and straight cuts. It there a limit to the radius that can be cut with certain blades?