LEGO blocks can be used to illustrate and practice some basic concepts of mechatronic devices (i.e. machines combining mechanics, sensors, actuators, electronics and software.) In this case it has been chosen to take a look at a coil winding machine. In the end, a mechanical model of such a device has been created.
Coils and transformers are made by winding many turns of enamelled wire on a coil former. While the principle is very simple, some additional requirements exist which make winding a good coil challenging:
- The wire needs to be evenly spaced across the coil former cross-section.
- The wire has to be kept under constant tension to prevent tangling.
- The number of wire turns needs to be consistently kept while winding.
- Should the wire snap (or should the tension be lost), the situation needs to be detected quickly to prevent the wire from getting tangled.

This implementation seeks to fulfill those requirements.