One of the things I’ve been experimenting with to reduce cost of a 3D printer system is a system of rails and pulleys, to eliminate the linear bearings and lead screws that are used in the more conventional RepRap designs.

With a table saw, a straight V shaped groove can be cut on the underside of a plank.  With a matching rail shape, an extremely simple linear slide can be made, with very good stiffness and no slop.  As long as the lateral forces are low, which they usually are with a FDM style printer, this ought to work well for very low cost.

Here is a video of an earlier attempt, using primarily particle board.  The grooves and rails were made using a table saw.

(Original video taken August 8, 2014.)

(This setup was later torn down and rebuilt because poor planning had left no way to securely attach a Z-axis above the XY table.)