I've made quite a few items out of High Molecular Weight Polyethylene. It machines well and is fairly abrasion and friction resistant. Cuts, drills, taps well, but won't sand and forget about gluing.
ABS is good when you want to weld pieces together. Just cut to size, position the parts and flow a bit of methylene chloride into the joint. Give it a bit of time to set up and you're done.
Methylene chloride also works well with acrylic (Plexiglas) and polycarbonate (Lexan).
Mike