On 2/2/2015 2:09 PM, dpb wrote:
On 02/02/2015 2:38 PM, DerbyDad03 wrote:
...

I vote against Al because it tends to gall/stick worse than steel.

Other than that I have no real strong opinion although I am partial hard
maple as the material of choice simply 'cuz it's easiest to sneak up on
the prefect fit...even the purchased steel runners are typically a
little sloppy...

UHMW (Ultra High Molecular Weight) polymer bar stock works well.
http://www.ttrackusa.com/UHMW.htm