woodsmith, they haven't nicknamed you "old school" have they? That's definately doing it the old school way.
Josh, I took a piece of angle iron and cut it 3" long and hammered it closed enough to cradle my torch handle. I then welded a piece of 1/4" rod into the bottom of the cradle, making a pivot point. I sharpened a point on one end while it was long, then cut it so that my torch is held up about 1/2" above the plate I am cutting. So if I want a 14" circle I measure 7" from center of my tip to center of the point on the cradle and then lock the cradle down onto the torch handle with water hose clamps. Use a center punch to make a guide hole in your material, fire up the torch and put the sharpened point in your punched guide hole and start cutting and pivoting until you get around your circle. If you don't want a blowout hole from getting started, drill a small hole to start your cutting in. There is no weaving from an unsteady hand.
So then you lay your cut out circles flat on the table and grind down the top and bottom only, getting all slag off. Drill a 1/4" (or whatever size you choose) hole in the middle of your circle in that guide hole you punched. After drilling both plates, remove your drill bit and slide it through the holes you just drilled in both (or 3-4, whatever you feel you can handle) of the plates. Clamp a pair of vise grips to each side of the plates straight onto the drill bit to use as a stop and to give you a good set of handles.
Take a big sidegrinder and clamp it in your vise. Hold the trigger down and lock into place letting it run without touching it. Now pick up your circles holding both pairs of vise grips and grind the edges on the running sidegrinder.If you hold them straight into the grinding wheel they will gain speed and turn as fast as the grinder. Twist them sideways, it makes the grinder cut better and gives you control of the speed of your circles.
By grinding them all together and letting them spin on the drill bit they will come out all exactly the same and will be perfect circles. If the hole in the center bothers you, weld it up and grind it smooth.
My buddy actually bet me 5.00 he could cut a perfect circle with a torch. I thought about it for a minute and reasoned it would be worth 5 bucks to know how to do that, I didn't doubt him, just wanted to know how to do it. It worked. So now I have done the same to several others and got my 5.00 back more than once.
To anyone that reads this, please drop 5.00 in the mail...lol.
