Best way to cut a circle?

[Brent Romero]

Good Evening Gentlemen,

I am building a new table for my Big Green Egg...finally putting some of my new tools to work. I am going to need to cut a circle ~20" in dia. and I am wondering what the best way to cut the circle would be. I was planning on routing the edge with a semi-round router bit..or maybe just a roundover.

Thanks for the tips.

[Steven Hsieh]

I've seen people do it on the table saw. I couldn't do it.
I would use router or bandsaw.

[Sam Murdoch]

What do you have for tools? A good bandsaw or a router and guide would be my first choices.

[Brent Romero]

Thanks guys. I forgot to mention that I need to cut a hole with an ID and not a circular piece of plywood. Not sure how I would use a bandsaw. What type of router guide are you referring to?

[Cody Colston]

What type of router guide are you referring to?

Something like this...I make mine from 1/4" plywood or MDF.




236253

[Brian Kent]

This router circle cuting jig has worked excellently for me.

http://www.rockler.com/product.cfm?page=30473&site=ROCKLER

On this project I cut 4 full circles and the inside and outside curves on 24 pieces, a total of 48 curved tongue and groove joints, and the jig never slipped on me.

[Mike Heidrick]

Jasper jig makes a indexed circle jig that will give exact perfect circles. The jig comes in 3 sizes. They are what a lot of DIY speaker guys use. I had one of those in my car audio days long before a shop or any big tools.

[Rich Engelhardt]

I'd use a router and a trammel - which is what Cody has pictured.

Make sure the one you construct is good and solid. Any slight movement in it will snap your router bits like toothpicks - as I found out the hard way.
I used some scrap pegboard for mine and broke three 1/4" bits making one 24" diameter cut out.

I posted here asking why the bits were breaking & Pat Warner told me it was due to the inadequate jig flexing.

[Van Huskey]

Router and a circle cutting jig either commercial or shop built is the way to go.

[Erik Loza]

Bandsaw would be my first choice, followed by the router....

http://i75.photobucket.com/albums/i315/erikloza/Mini%20Max%20Bandsaw%20Works/CircleJigRadiusCutting1.jpg
http://i75.photobucket.com/albums/i315/erikloza/Mini%20Max%20Bandsaw%20Works/Circlecuttingonbandsaw.jpg

Best of luck with your project,

Erik Loza
Minimax USA

[Matt Meiser]

I'd use a bandsaw or jig saw to cut most of the waste, then finish with the router. The only issue, assuming this is real wood, is that there are two points on the circle where you are cutting unsupported fibers and can get some nasty tearout (think running your hand from tail to head on a dog.) Sometimes even if you are real careful.

[Brent Romero]

Thanks guys. I need to cut a hole with an ID..so the bandsaw is not the best option. Looks like the router jig is probably my best option. Will a 1/4" dado bit work for the cut?

[Brent Romero]

Found one of these at my local L..es store at 50% of the original $39.99 price. Probably discounted for obvious reasons but I am going to give it a shot. I doubt I will need to cut holes all that often.

http://www.amazon.com/Milescraft-12230713-Router-Guide-Kit/dp/B004OCH224

[Mike McCann]

a 1/4 inch spiral bit is the best

[Peter Kuhlman]

I just used a jigsaw following a pencil marked circle. Any variance in the cut is mostly hidden with the Egg in the hole. You need about 1/4-1/2" space around the Egg as it gets very hot during slow cooks.

[Brent Romero]

Thanks Peter. You sound like an egg enthusiast. How do ya like it?

[Jerry Miner]

A 1/4 straight bit or dado bit can work. I like to use a spiral bit for these cuts. What's the material and thickness? Take small bites: 1/4 cutting depth or less with each pass.

[Myk Rian]

You still haven't answered a few questions of what you are making it out of. That could slant the answers to the best way.

[Brent Romero]

Sorry...I am using 3/4" cypress. Some of the cypress is new cypress and some is sinker pecky cypress.

[Aaron Berk]

Can you support the off cut from the underside? and then use a standard router circle cutting jig pivoting from the center point on the off cut.

Clamp some cauls under your table, screw the waste portion of the table to the cauls, then rout away!

I would use a spiral bit if you have one, otherwise a 1/4" should be find as long as you route in steps not full depth.

[Peter Quinn]

For an inside radius, I prefer to make a template with a router on a trammel in 1/2" MDF or similar, then flush trim the actual work piece to the template. I'd suggest making three light passes with a 1/4" bit, or a 1/2" bit. If the inside radius is 20" I'd make the blank around 28" so you have a bearing surface for your router's plate to make using the template easier. I don't like using the trammel to cut all the way through the template as the the bit is between the template and the off cut at the end, and a loose but captive off cut can lead to problems. But if everything is well secured it goes fine, so remember to double stick tape or screw down both the keeper and the waste. Using a template on the actual work piece will allow you to always be cutting down hill in the curves to avoid tear out, and you can climb cut as needed too. Plus you can save the template to make another table for the same egg down the road should you air a friend need another one. I'd cut the circle in the actual work oversized using a jig saw or if glueing up to make your width, you might be able to save material by leaving most of the waste area empty to begin with. Then any decent pattern bit or flush trim should do it from there.

[Brian Kent]

Rockler is on sale for $32.99.

For inside circles I cut most of the way through, then use a pattern bit with the bearing on the cut edge to ge the rest of the way through.

[Jay Jolliffe]

I would go larger & use one with a 1/2'' shank....If you use a 1/4" go slow & take multiple shallow cuts. Don't try to do it all at once you'll bust it right off....I did a least...

[Peter Aeschliman]

I made a green egg cart for my dad a few years ago and made the exact cut your considering! Pretty fun project.

I used a router with a 1/4" straight bit, using a circle-cutting jig made of hardboard. If you're going to be doing lots of circular cuts in the future, then it's worth investing in a jig like the one pictured above.

The one very important caution here: you'll be anchoring your jig in the center of the circle, which will fall away when you complete your cut. If you cut the hole out after the top is already fastened down, make sure you come up with a way to support the center piece... I did it by screwing some pieces of scrap to the underside of the top in 3 or 4 places. This way, the center will stay put when you complete the cut.

This may seem like common sense, but I thought i'd mention it.

Good luck!

[Van Huskey]

BTW I need to amend my earlier answer the "best" way would be a CNC... Now I have given you the excuse to buy a new potentially really expensive machine.

Egg? Bah Humbug, get a Primo... more useful cooking surface but harder to cut the hole... well unless you have a CNC :D

[Andrew Hughes]

Nice hay raker table Brian,i am planning to make one for my house,What wood did you use looks great.