To guide a roller coaster vehicle safely over its track, it is necessary to enclose the track with wheels so it can’t derail. The only allowed movement of the train is forward and backward. The deviation sideways should be as small as possible, because of other equipment on the track like brakes, launches and chains. This assembly consists of 45 parts.
Improvements that can be made:
Do research on bearings and different axles. Investigate if an oil or grease supply is better than lubrication-free systems.