Teacher and Weightlifter
A simple model of two Meccano men: a teacher writing on a blackboard, and a man lifting weights.
The mechanism is driven by a video motor, geared down using two sets of worm gears and pinions, finally driving a shaft which runs the length of the model. At each end of the shaft is a bush wheel with an eccentric bolt. One end of a piece of thin wire is secured to this bolt and the other end is secured to one of the arms.
The ‘modern’ version of this model has a whiteboard rather than a blackboard since these are no longer used in schools! I have used all re-painted parts, a simplified mechanism utilising a geared motor, and constructed the ‘box’ all from Meccano parts.