There is a Thomson rail assembly that I modified for use on my CNC router as the Y-Axis. As it is set up it has 24" of travel. It uses 1" rails and has a 3/4" x 5tpi acme screw.

There are two supported 1" x 24" rails. One has two bearings mounted on it, and I am including two 1" open bearings that I believe are new and unused. The rails had some corrosion on them when I got them but I believe that they are still better than the finish you could expect using iron pipe and much stronger. I priced the aluminum supports at one time and they were $25 a piece.

There is also an approximately 18" section of 1" shaft mounted on a separate support piece.

All of these parts except for the two extra bearings were purchased used.

This stuff is quite heavy, so, local pickup would be best. But if someone wants me to crate it and ship it we will have to agree on a price for that. It weighs about 70 pounds without any packing material.