Some years ago Sears used to market a device for turning spirals on
legs. I am sure it had other uses as well. It was a bed with some
sort of mount above for seating a router. It had a crank on the end
and I believe was wire driven. You could turn the crank while running
your router and do spiral work quite easily. I am looking to buy one
but need to know what they are called first.

Joe