Woodworking: Router Replacement?
I (will) have a disc of plywood roughly 20cm across. I need to cut a spiral notch in the ply, from edge to centre, around 3mm wide, so that I can hold a spiral of flexible ply in place and close off the end of the spiral at the same time.
The perfect tool for the job is, of course, a router.
I don't have a router.
Short of buying a router just for this one job, what can I do to cut the notch?
I've been saying "plywood" - is there another material that can be shaped the same way?