I have just about finished my pantograph router and I am thinking how nice it would be to add CNC so the requirement is to move the trace point in X and Y directions.

Rather than use screws or whatever for such lightweight work I am wondering if a cat's cradle would be practical. The principle is simple, for the 'Y' direction a single wire (stainless steel fishing trace for example) is routed around four corner rollers and doubles back on itself so that there are wires on each side of the rectangle moving in the same direction and a cross piece is anchored to these wires so as to move in a parallel fashion over the base. A simple loop of wire and a single stepper to be fixed to the cross piece to give the 'X' direction.

My plan is for a 30x30 inch X,Y, rectangle which, as my pantograph scales 1:2.54, gives me a 30cm square work space for the router.

Anyone use wires for linear motion?

Thanks.