Simple circle cutting apparatus

[Tmate]

Some 30 years ago, I put together this circle cutting contraption using a magnetic base, a Grainger gearmotor, and a toy train transformer. It worked, but would have been a lot better if I had used heavier parts. Back then, all hobbyists had was acetylene torches. Today, a hand held plasma torch moved around a circular steel template would accomplish pretty much the same thing.

 

[Tmate]

Here's another -- this one was a track cutter. Again, it used a Grainger gearmotor and a toy train transformer. Two wheels in the foreground had V grooves in them so the could ride on an inverted angle iron track.

 

[Gaffer]

Very clever. Adapt and overcome!

 

[pontiac428]

This is how I've been doing it. Works equally well for small circles or large, there's a slight learning curve to getting nice parallel cuts, but otherwise it's pretty easy.