Full size Rostock adopts the 8mm smooth rod in 762mm long, but it seems too thin for that tall.
Here is the set 6pcs 12mm D smooth rod in 762mm long which is used for Rostock would be stronger.
- Timing belt: 3x 1524 mm GT2 belt (2 mm pitch, 6 mm width). Closed loops or open end is okay.
- Timing belt pulleys: 3x GT2 plastic pulleys with 40 teeth. Smaller would probably work better.
- Smooth rod: 6x 762x12 mm precision smooth rod. Drill rod is probably okay too, but some report that the bearings wear grooves into the surface as drill rod is not as hard as smooth rod.
- Linear bearings: 6x LM12UU