I'm making a kinetic log splitter using 5 Chevy 235 flywheels spinning on a 1" shaft. The motor is an Army surplus 2-cyl 9 h.p. motor. There is a pinion gear on the shaft that drives a rack that pushes a sled 26" down a 6" wide H-beam. The sled is 6" X 6" and weighs about 10 pounds. I'd like to lessen the drag on the sled so was thinking of fastening two strips of low-friction materal to the bottom of the sled. Does anyone have a suggestion what I could use? I thought about ball bearings but the design of the sled rules out ball bearings. The sled and H beam are both mild steel. At one time I thought of linear slides but I don't know if they are stout enough.