Introduction: How to Cut Perfect Circles With a Table Saw
Table saws are great at cutting straight but when its time to cut circles most people think of other tools, bandsaws, jig saws, hole saws, routers... etc
Well you can cut perfect circles on your table saw too, with a simple fixture!
What you'll need:
- Table Saw
- Short nails, staples, screws (1")
Step 1: Make a 'Burner Sled'
A 'burner sled' (a term I made up), is a sled that rides back and forth in your table saw's channel guide that you don't intend to use ever again - as opposed to just a regular table saw sled which had a nice fence perpendicular to the blade and lets you do lots of stuff. You could use one of those but you'll be drilling into it
Make your burner sled start by measuring the width and depth of your table saw guide channel and then ripping a piece of plywood to fit in the channel (shown)
Step 2: Make a 'Burner Sled' (cont)
Nails/screws/staple a larger piece of plywood to the channel guide key you just made.
Make sure you're fastening hardware doesn't go through both pieces and damage your guide channel.
This is a good time to mention not to forget to take off the fence that came with the table saw and put it aside.
Step 3: Position Your Cutting Piece
Your cutting piece can be any shape. This one is a square.
Place your cutting piece on the burner sled and push one of the sides up against the blade
Before you get a feel for this technique it helps to start with a much larger piece than the circle you intend to cut (a few inches at least) so if you intend to cut a 10" diameter circle, throw a 14" squire on there (2 inches of margin on each side)
Step 4: Attach Your Cutting Piece
Now screw your cutting piece to the burner sled, but not too tightly - you want it to spin.
For best results drill a through hole in your cutting piece.
The distance from the screw to the blade will be the radius of your circle
Step 5: Cut Corners (literally)
If you don't already have a square cutting piece, make it one by moving the sled past the blade, clocking the cutting piece by 90 degrees and then running it though again.
Once you have a square, index the cutting piece by 45 degrees at a time and reduce your square to an octagon
(as shown)
Step 6: Cutting More Corners
Now cut off the corners of your octagon shape to make it whatever a 16 sided shape is called....
...hexadecagon (according to google)
Step 7: Finishing Cut
Once you have 16 or more sides you can keep the sled stationary and spin the cutting piece (slowly) to remove the rest of the material. The result... a perfect circle
209 Comments
Tip 5 years ago on Step 4
Your cutting piece needs to touch or extend past the blade on all sides when it's screwed down or you will not get a complete circle.
Reply 4 years ago
I agree, Chris. You will notice that the piece of plywood changes because the first piece of ply was too short and would have had flats on it when finished.
5 years ago on Step 7
Great Idea. I am not a wood worker, but a Model maker. I do not have much Table saw experience. I was wondering if you think a fixture could be mounted to the fence so that you could cut different size diameter circles? Just a thought.
5 years ago on Introduction
Very good tip. I need to cut some circles. I was planning to buy a bandsaw that will just occupy space in my very small workshop. Thanks for posting.
5 years ago on Step 2
NO GLOVES, jewelry, or long sleeves/loose clothing,,, EVER!
5 years ago
By the way, one thing that I missed. Loose the gloves and any long sleeved shirts.
Reply 5 years ago
Long sleeved shirts should read, loose clothing.
5 years ago on Introduction
As a teacher and home builder with 50 years of experience, I say that this method of cutting a circle is not for beginners. Get some help from an experienced person before trying this method, and even then use these two most important safety tips. COMMON SENSE AND GO SLOW. I agree with all of the comments that indicate the table saw is very dangerous unless the above two safety tips are used.
5 years ago
There are so many safety comments because there are so many experienced wood workers that had minor panic attacks about this method.
And each and every one of them was trying their best to protect someone. I respect every one of those connectors and have nothing to add except keep control of that board - press down HARD and feed very SLOWLY.
Very slowly
8 years ago on Introduction
you should add a warning that it could be dangerous to do this. since you are using a open top circle saw
Reply 8 years ago on Introduction
Table saws can be dangerous. Very dangerous. Very, very dangerous. Etc.
http://www.sawaccidents.com/table-saw-injury-pictu...
BE CAREFUL.
Reply 5 years ago
So can cordless power drills as I drilled through my thumb with a 12 mm drill bit. Not as bad as a power saw.
Reply 8 years ago on Introduction
Driving to work is dangerous. Walking on slippery surfaces, wearing flip-flops, bad relationships, too much McDonalds- all potential killers, without the added warning. ...since you are policing for labels.
This is a fine instructable. Having a warning about every nuance of tool use would over-burden any author, to the point of defeating the purpose of this site.
Thanks
Reply 8 years ago on Introduction
Let's turn this around. pmsfo, create an instructables on how to opperate a table saw safely. There is even a safety contest going right now.
Reply 8 years ago on Introduction
Amen brother
Reply 8 years ago on Introduction
Yes.. I agree with you.. everything in our life is a risk.
Reply 8 years ago on Introduction
You must be a trial lawyer or a liberal dumocrat
Reply 8 years ago on Introduction
Some of us liberal dumorats are the finest craftsman you could ever meet and we understand 10 fingers and two eyes are better than 8 and 1.
Reply 8 years ago on Introduction
Posting online could be dangerous. Too much will lead to carpel tunnel. Better watch out.
"open top circle saw"... Because "Table Saw" is too vague? ;)
Reply 8 years ago on Introduction
actually, there's no need to remove the top guard on the saw. You can use this method with the guard in place, no problem.
But I also want to mention that this method has been known to carpenters just as long as there have been table saws around... nothing new under the sun.
But thanks for bringing it up again.