The Future of Inefficient Transportation

by Paul Chase

For a long time now, the title for the least efficient velocipede was held by Wilbur and Orville Wright, having narrowly snatched the crown from Buster Keaton’s hobby horse. Fast-paced modern times have lost sight of the importance of inefficient transportation, but the visionaries at the American Visionary Art Museum in Baltimore, MD, have attempted to liven things up with their Kinetic Sculpture Race. While the race isn’t running this year, Nova Labs has got you covered!

Buster’s walking with style.

The Wrights famously attempted to build a bicycle but ended up with a series of wheelless wonders that were exceptionally bad at touching the ground.

I present to you the anthroelectric hybrid pneumaticycle: the Winded Scotsman, which is truly one of a kind. The pedals of this mad machine are not connected to the wheels at all – instead, they drive a 3D printed pulley that drives an air compressor. While a bicycle achieves upwards of 95% efficiency, this air compressor is maybe 60% efficient – here we convert all that superfluous energy into heat and a lovely popping sound.

That’s not all, though! Once the air’s in the tank it’s routed to a pair of dual-acting pistons doing their best impression of a piston steam engine, with an efficiency that’s certainly in the single digits - yes, the efficiency of this system is something like three whole percent! Cam-controlled valves keep the cylinders 90 degrees out of phase so that one is always pushing or pulling when the other is fully extended or withdrawn.

The end result of all this is something like an enormous spring sitting between the pedals and the wheels – it’s a wonder that it works at all! After pedaling for 10 minutes to travel roughly one block, I decided to turn it into a hybrid with a pressure-control-switch and a large lithium battery, increasing the range from “downhill” to several miles! One glaring issue remains, and that is the heat generated by the compressor.

The power input cycle. Pedals drive the chain drives the belt drives the compressor. The gearing increases the speed of the compressor, which is still nowhere near what the electric motor can do.

Why would someone build this? Because I can. Which is deceptive – when I started this project, I could NOT – in fact, I’m still just dabbling in how pneumatic components work. However, I can now read control valve diagrams and have a modicum of experience in the area – problems, control, and safety – which adds tools to my maker toolbox. Parts are insanely available now – the total cost of this project was under $300 – and it added to my knowledge base in computer-aided design as well. Furthermore, I hope the project inspires some of you to try something outlandish – because you’d be amazed at what you can do.

The control valves are at left - cams in blue - and the thin red tubes actuate the double-acting valves on the right. The pistons are mountedto the cam to transfer power to the wheel through the chain; rearcylinders are mounted in flexible plastic so they can bob up and down.

Energy storage quiz - what holds more, the gigantic red air tank, or the comparatively small battery on the left?

Further Reading Unbeknownst to me, I’m not the only fellow working on this staggeringly important problem! Previously known as the Chainless Challenge, the problem of powering a bicycle without chains is used to inspire young engineers. Check link - https://nfpahub.com/news/chainless-challenge-a-proven-way-to-engage-young-engineers-in-fluid-power/

Even these luminaries are mostly using hydraulics - apparently due to some sort of wisdom they obtained with their mechanical engineeringdegrees.