DIY Printers. What degree of accuracy is OK?

I'm chasing some comments on the degree of accuracy of movement we should be accepting. I want to know how finely tuned the movements have to be to produce an acceptable product.

I want to make a large printer with a 4ft x 4ft printer bed. To move the X & Y axes, I want to use thin steel cable instead of toothed belt. I want to wrap the cable around a cylinder fitted to the shaft of a 1.8 degree per step motor. The cable would be attached to the printer bed and X axes in the same way as they are in a Prusa printer.

If the cylinder has a radius of 7.95mm, then at the circumference, each step moves the cable 0.25mm. Bearing in mind that this large printer would not be used to print the small things that a desktop printer would be used for, would that be accurate enough for movement in the X & Y axes?

I am going to use threaded rod for the Z axis movement.

Old Man Emu