Fighting against a tough headwind on your daily cycle can be a drag, but [Emiel] of The Practical Engineer, has a loud and bold solution. In the Dutch video after the break, he builds a transforming backpack with two electric ducted fans (EDFs), and takes to the bike paths.
An EDF moves a small volume of air at high velocity, which doesn’t make them great for low speed applications. But they’re nice and compact, and safer than large propellers. [Emiel] didn’t skimp on the rest of the hardware, with the motors attached to metal 3D printed arms, mounted on a machined aluminum steel plate.
The arms were printed courtesy of a sponsor, and created via generative design in Fusion 360 to make them both light and strong. A pair of large servos swing the arms up, while smaller servos rotate the motors into the horizontal position. The arm servos are controlled by an Arduino, and activated by a simple toggle switch attached to the backpack’s shoulder strap. A wireless remote similar to that of an electric skateboard is used to control the EDFs.
Fitted in a [Emiel]’s old backpack, the result looks somewhat innocuous (if you don’t look too closely) until it unfolds its hidden power—twin jets ready to blast away any pesky headwinds with the push of a button. It’s a fun solution that is sure to attract attention, and a great excuse to create heavy duty mechanics.
I know better, more energy efficient, more silent solution to a headwind problem. It also does not put strain on your back. It is called – e-bike. ;)
I know it is less fun than having kind of jet pack, but works more efficiently. :)
He’s Dutch, aero.
I’d expect a rudder.
For steering.
Okay, but my e-bike is having trouble cracking a top speed of …. *Some number less than 45 kph here*.
Aero is actually the problem if I’m to limit myself to a lawful 750W
I think your efficiency isn’t good enough, and that many bikes can exceed that speed with that power if they’re not going into a bad headwind or uphill and the surface is good.
As a person whom has experienced traumatic hearing loss from, of all things, a poorly designed oxygen hood in a medical hyperbaric therapy chamber, I would take extraordinary steps to protect my hearing using this device or iteratively design it to mitigate the sonic effects such as impeller shape, duct shape, baffles, etc.
Once it’s gone, it’s gone, and I can tell you 24/7 tinnitus of no fun.
Toroidal props in the EDF would be an interesting experiment. They cut a lot of sound out.
EDFs are already toroidal – the duct connects fan blades into a loop.
*IS* no fun.
Can we PLEASE have an edit button???? It’s 2024. We’re living in the future! CompuServe figured this out 40 years ago!
Could be used to bypass regulations on E-bike speeds in some places. Anything that can reach above 25km per hour on its own here in France is basically considered a moped
Thanks to car / petrol lobbies. At the moment there is an alternative, it is dangerous.
Seeing how recklessly people drive electric scooters around, I don’t mind there being the requirement of a license for anything that’s capable of going over 25 km/h with no effort.
Knowing there would be noise I watched the beginning and heard how little speech there is with just pedaling wind noise now I want to hear the increase, quick deployment and cut… Couldn’t hear the increase in sound of the fans which is what I came to hear. The rest could have been done with a couple of 555’s and FET’s.
Editing with music videos, argh.
Totally sucked in by this, and then I remembered that there are other simpler, efficient methods to electrically propel a bicycle. Totally cool build, though.
Had to look some things up. You can easily get 5-10lbs thrust from a single edf. 5lbs of force should be able to maintain 15mph on level ground with decent tires.
Can someone who speaks dutch post the 1) output power in watts, 2) weight, 3) battery life/mAh? Thanks.
Quick napkin calculation says 2 50W fans with 2h of battery life would require 24lb of lead acid or 5lb of lithium ion battery. Subtract 50W in drag from the backpack, fan mounts and more vertical riding position and you are looking at best case 50W extra power for 10lbs weight (battery is not the only weight), halve that if you are riding for more than 2h so if you are a decent cyclist (already doing 4w/kg) would this even increase your speed or are you just adding stuff for no reason?
I would love to see stats but I don’t speak dutch. Also which company paid for this the youtube says “includes paid promotion”..
Rather than a backpack, I could imagine it mounted on a rear rack in a streamlined pod.
EDF is nice and all, but a couple of Jetcats or similar would be more fun (with suitable hearing protection of course)
Pulse jets for the win!
Loud pipes save lives!