The centaurs themselves have great lower body strength compared to humanoid races. They combine both horse and rider in one body making wagons, carts and plows commonplace and providing employment for the low skilled with the plodding labor of pulling and porting. Centaurs have expanded many tools to take advantage of their equid body - none so significantly as the treadle. They can set themselves as teams for running mills and drills, power paddle wheel boats and many industries established where ever they please that others must have trained draft beast teams or access to harness swift rivers or waterfalls. The main toggle or wheel turns other gears and wheels that then may turn a flat or standing wheel or repeatedly raise and lower or drive back and forth a bar.
From pottery wheels, bow saws, greater wood turning and sawing, spinning and weaving and milling grains the centaur industry uses rocking pedals ( as are commonly known in humanoid sewing and pottery machines), great wheels in which one or paired centaurs walk or run, or running tracks of boards linked with leather or secured to chains attached to rolling wheels or pins to turn cranks and wheels. These devices are much more powerful than the hand crank or simple toggleboard found in the human lands. Centaur crane and tackle lift great stones and other loads quickly and far more efficiently with the leverage, counter balance weight and brute strength of centaur workers.
One of the most remarkable creations is the centaur paddlewheel boat. These craft move up and down streams under their own power with or against the flow and largely ignoring wind. They may be small craft for one or two or larger ones for passengers and cargo with trained teams to run the treadle chain for the turning of the wheels. Typically there is a rudder and two wheels to make the craft very maneuverable.
by Mutterwolf
The power of the treadle board system allows centaurs to apply powered efforts at a fraction of the labor of hand and arm work and to things when and where they wish. Because the centaurs themselves power the devices they are more coordinated and controlled than if powered by draft beasts. They apply wheels to lift water for irrigation, to power watercraft and for industry in construction and building, wood work, ceramics, and fabric production that does the work of many with only a few workers.
This is a really cool little piece of tech and the vehicle, though simple to envision, seems it would be a unique joy to theory craft and build. Well done. :)