Super cheap HO scale roller test stand

thingiverse

This test stand is an affordable and straightforward setup for locomotives with rollers, designed to get the job done without breaking the bank. It relies on washers as rollers, eliminating the need for bearings in the process. This results in a bit more friction but still delivers satisfactory performance if assembled properly. The rollers are placed on a code 100 track, and it's likely that other types of tracks will work just as well. For a 4-axis locomotive, you'll require four units like this one to get started.