Free-rolling Steam Locomotive Drive
Model Railroader 1985-11
The author converted an NYC Mohawk such that it can be pushed down the track by hand. The conversion included building a multiple-thread worm, thrust ball bearings, and a coreless motor. The idea is that if you can easily push the engine down the track, when it receives track power, it will run very smoothly. Detailed photos and diagrams are included.
Motor and Locomotive Speeds
Model Railroader 1986-12
Jack L. Baer
The author shows how to accurately measure and calculate an engine's scale model speed.