The triangular structure of the treads has been built after precise
studies of real Johnny five photos: a pre-production CAD drawing helped
this process. An early version of J5 base had the most perfect
proportions achievable with Lego gears, using Technic large turntables:
unfortunately, those turntables made links escape while treads were
So, in the actual version, turntables has been replaced by 40z
gears, that don't damage design too much and allow a very smooth motion.