The Octagon reciprocating movement is transmitted from the motor to the incubator cradle via a 'long link' a simple plastic connecting rod. However the plastic is thin and the socket or bearing where the motor crank pin engages is left with very little 'meat' around the socket. It is a part which, in my experience, is unable to cope with moving the cradle for very long and the socket fractures. The link needs a redesign to beef it up. Naturally the failure occurs whilst eggs are being incubated, which might result in a total loss, unless some quick action can move the eggs to an alternative environment. I do not think a stronger design would be difficult, just copy the shape of an internal combustion engine connecting rod.
