Custom-made speed reduction modules can be stacked to achieve very high gear ratios.
This 1:32 prototype uses 180 steel balls in 5 modules to achieve the reduction. I noticed a relationship between balls rolling between two surfaces in the mid-80s, and I've finally managed to implement this reaction to create these reduction modules.
https://youtu.be/LkAdnE86K8k?si=M61DUfdHdxsiA8ly
