cutting a 40 inch circle

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I need to cut a 40 inch circle out of 11 gauge steel. My ideas so far are as follows....do it with a torch, will that distort the sheet?? use 14 gauge and buy some kett shears. Will those shears have any problem cuttin a curve that big? How often do the blades go bad on them? Is it easy to cut agaisnt a curved guide? this is the model im considering http://www.toolfetch.com/tools/KD-440.html I havent decided on air or electric
Reply:I could cut you a 40 " circle on my c.n.c. don't know if the shipping would be worth it though from canada -let me knowKeep your stick on the ice
Reply:how does your cnc cut torch? plasma?
Reply:Center punch a hole and buy a radius-type torch cutter.  With the correct tip, a torch will cut 11 ga just fine although a Plasma head may be cleaner.Get it hot and hit it hard...
Reply:cut quality isnt as important as not distorting the sheet
Reply:yes I have a c.n.c plasma  cutter, what are you doing with the 40" circle that cut quality doesn't matter so muchKeep your stick on the ice
Reply:There will be some distortion with torch, buying a small new tip will help.www.urkafarms.com
Reply:Why not a metabo with a few cut off wheels?  revpol
Reply:It'd be slower but you could cut it on a vertical bandsaw. A circle cutting jig is easy to make. If you've only got one or two to do i think this would be a good way to go about it.Andrew
Reply:You could drill a pilot hole in the center of the piece you want to cut and attach a bolt. Then take a 1" wide 24" long strip of metal and drill a pilot hole in one end.  Place the hole in the strip over the bolt and loosly tighten the two pieces together. Then appropriately connect the other end of the strip to a jig saw base. Now you can cut a fairly accurate hole without worrying about heat distortion.
Reply:I reread your original post and I see that you want to cut a 40" circle not a 40" hole, so maybe you don't want a bolt hole in the center of your circle. You could tack weld the bolt to the center of the circle temporarily and then proceed as I said. Or you could use the same technique on a band saw. Tack a bolt or pice of rod to the material. Then use a thick strip of metal with a hole in one end to locate the stud and clamp the other end to the table of a band saw. Then when you spin the material you will cut a perfect circle.
Reply:Know someone that has a plasma cutter? Take a piece of scrap 1/4" plywood, about 2" wide and cut a hole in one end to hold the torch nozzle. Get one of those cheap magnets they use for fastening the welding ground lead to steel and weld a nail on it and then hammer it in 20" from where the the plasma head is. Instant circle cutter. Probably no distortion.Hobbiest hack
Reply:I would use my plasma cutter, very simple since I made a circle cutting attachment for it a couple years ago. You can just use a center punch in the center instead of drilling a hole.Last edited by MPK; 03-10-2005 at 08:11 PM.Reason: additionWelder- Miller Thunderbolt AC 225-DC 150 Plasma cutter, Miller Spectrum 300O/P torch- Victor 100