Here is a basic drawing of a cable drive system. It uses just regular 1/8" cable
I know a lot of people don't think it works, but i have a 16 yr old machine that i have owned for 10 yrs. We have never had to do anything with the cable system.
The machine cuts at 350 ipm and we run a couple of tons of lite metal a week. I am going to include it in the free plasma table plans as a alternate drive system once i can find the right pulley.
You will need to reduce the speed of the drive.
if anyone is interested I will come up with some better drawings.