  Self-similar space-filling bearings have been proposed some time ago as
models for the motion of tectonic plates and appearance of seismic gaps. These
models have two features which, however, seem unrealistic, namely, high
symmetry in the arrangement of the particles, and lack of a lower cutoff in the
size of the particles. In this work, an algorithm for generating random
bearings in both two and three dimensions is presented. Introducing a lower
cutoff for the sizes of the particles, the instabilities of the bearing under
an external force such as gravity are studied.
