Nylon roller 4-wheel carriage with eccentric spacers and Rostock printed u-joints

These are carriages with eccentric spacers (inspired by the eccentric spacers Openbuilds uses) that can be customized for whatever rollers you can find, with a GT2 belt clamp and Rostock's printed u-joints.

Cautionary tale: If your carriage doesn't move smoothly up and down, it could be due to your wheels being oval, which would cause your layers to shift with a period of half of the wheel circumference.