A new product I'm developing, the Treadwheel Crane. This is a desktop sized model of a "treadwheel" crane. Based on a design by Jean-Rodolphe Perronet in France, 1750, this crane was used in construction of a bridge in Orleans. The bridge was his design also. This is a fully operating model. It stands about 18 inches (~450 mm) high.
This type of crane can be seen in paintings from the period, where a human would walk inside of a wheel, providing lifting power for the crane. My model follows Perronet's design as much as possible, even using timber frame construction techniques such as a scarf joint to make a single long beam from two shorter beams. I also used brass for detail parts like the clasp bolts and several pulleys.
I expect to make this available in 2024.