I’ll probably don’t have to tell you that building trains on scale comes with a lot of extra challenges. I’ll try to write a series of short articles or tutorials on how I tackle those. These are certainly not the only on definitive way to solve these, but they are how I solved them.
This first article will probably be the most fundamental, wheels, axles and ball bearings.
First of all I have to give major credit to this thread on Eurobricks. Most of the necessary info can be found there, but I get my bearings from AlieExpress: here (I wish I got money from this…) The type of bearing you will want to get is the MR52ZZ (5mm outside, 2mm inside diameter)
These bearings fit with some minor force into a LEGO technic hole, I use the vise my dad has in his shed, but I’ve heard positive results from using glue clamps, small hammers or basically anything that allows you to apply steady pressure. Make sure to fit the bearings on the outside of the parts you use.
The next thing I fairly recently added are small O-rings, I use the M2 sized ones. These rings add a small gap between the flange and the frame of your wheels, which reduces drag.
These O-rings are only needed when you use the wheels and axle from 2878c01 and 2878c02 (You’ll probably need to glue these as they tend to fall of) on a 4 studs wide frame. The wheels designed by BrickTracks have a slightly larger hub for the axle allowing the flanges to clear the frames.
I’ve added some of my bogie designs with how I added the bearings in them, happy building.