Fixed wing remote control planes are ridiculously overpowered. Whereas normal, manned fixed wing aircraft need to take into account things like density altitude, angle of attack, and weight limits, most RC aircraft can hover. This insane amount of power means there’s a lot of room for experimentation, especially in new and novel power plants. [Samm Sheperd] had an old squirrel cage fan taken from an electric wall heater and figured one man’s trash was an integral part of another man’s hobby and built a plane around this very unusual fan.
The only part of the squirrel cage fan [Samm] reused was the impeller. Every other part of this power plant was either constructed out of foam board, plywood, or in the case of the brushless motor turning the fan, stolen from the ubiquitous box of junk on every modeller’s workbench.
The design of the plane puts the blower fan directly under the wings, blasting the air backwards underneath the empennage. During testing, [Samm] found this blower pulled around 350W from the battery – exactly what it should draw if a properly sized propeller were attached to the motor. The thrust produced isn’t that great — only about 400g of thrust from an airframe that weights 863g. That’s very underpowered for an RC aircraft, but absurdly powerful for any manned flying machine.
Does the plane work? Of course it does. [Samm] took his plane for a few laps around the neighborhood and found the plane flies excellently. It is horrifically loud, but it is a great example of how much anyone can do with cheap RC planes constructed out of foam.
wow Coool
read too fast, First I thought hamster powered flight….
Same here
It sounds like a turbo in heat, but nice project :)
How does the precession feel on that? I imagine it having wicked different turn coordination at high throttle vs low.
Madly cool project! So much nicer a way to build than the balsa and dope of my dad’s generation.
Unusual fan?
Any column fan runs a centrifugal :) , tall or small . I actually have one right next to the screen :P .
They are way more common for industrial uses, though :p
That is actually a cross flow fan.
i was actually going to do something similar with the bldc and impeller for a quieter dust collector for my cnc
Bit more practical, don’t have to worry about weight. Though I might actually recommend a 110V brushed motor, from a blender or something, so you don’t pull from your power supply.
That’s creative. I give you the first also but who knows.
Next up: fanwing
Next up use Dyson centrifugal vortex style fan.
I wonder how those jet blowers McDonald’s have been using for a while would fair in this sort of design. [The ones that try to take the skin off your hands with the water.]
Talking of dyson they have invented a new battery http://sakti3.com/?page_id=46
Not quite enough for laser heating air (:
That would be cool.
like this prototype
https://www.youtube.com/watch?v=LAdj6vpYppA#t=2m12s
Buld A ZNMF style system?
http://www.petervis.com/interests/published/Supersonic_Bi-directional_flying_wing_SBiDir_Sideways_Flying_Plane/ZNMF_CFJ_Airfoil.html
Maybe a souped up version of one of those blameless fans. A bit like that loop shaped paper plane that one the distance/time in the air record a while back.
Blameless fan?
I didn’t do it!
It’s not my fault!
B^)
All fans have blades they just hide them and call it bladeless.
Yes, “bladeless” (stupid auto correct)
Not truly without a fan, more a different ducting design but perhaps if it were spun as it exited the side of the ring and the ring was tapered, it could pull through and concentrate more air.
The electrostatic “fans” does not have blades, but maybe they aren’t technically fans. Probably hard to get enough trust out of one of those for an rc airplane either way :)
Yes! Fanwing! I’d love to see what happens if you could duct all that air over the cambered upper surface of the wings. Should pick it right up.
I think there very well may be a superb use for this power plant: high speed flight. I do not believe it’s thrust would fall off with airspeed as does a normal propeller driven aircraft, allowing high-speed flight on modest power consumption. That’s why jets fly so fast.
Nope. Centrifugal compressors were on the first jet engines to take flight, but quickly proved inferior in performance to axial compressors, the only benefit radial compressors have against axial is cost (usually you need just one stage, an axial one needs many) and size…
I thought that centrifugal and axial compressors were relatively comparable but that axial won in jet engines basically because they’re long and skinny as compared to centrifugal being short and fat?
So you have this rather big flywheel turning (the squirrel cage) … and it probably acts like a gyroscope. So how does the plane handle when you try to turn perpendicular to the spinning cage? Do you have to compensate for that somehow? I would think it would resist the turn and pitch up or down radically.
He did compensate for this with a gyroscope in which he added latter in the video.
What I’m interested to see is two of these implemented with counter-rotating drums just like how a quadcopter rotates its blades.
But did he register it with the FAA?
What I find most cool is the point where he comments on the handling, and ten seconds later he’s got a 3-axis gyro on it to fix it, like that’s an everyday thing to do… What’s cool about it it that it IS an everyday thing to do, these days. These are great times when stuff like that is quick, easy and cheap.
– These are great times when stuff like that is quick, easy and cheap.
And soon to be verboten pretty much everywhere.
I know he had only one fan but, what about two in the wings with the inlet facing up and servo controlled thrust nozzles, all running off belts on a single motor mounted in the body with the shaft vertical?
Now imagine if he’d done it the even better way, and had the exhaust air blowing out over the top of the fuselage, and not the bottom? The Coanda force would be lifting up, instead of pressing down.
If squirrel cage blowers are so inefficient and noisy compared to axial blowers they why are they commonly used?
Better performance (W/CFM) with significant back-pressure
This is awesome. Reminds me of the VTOL (without the vertical) of the Harrier Jets down at Cherry Point. Very cool. !st place, Samm!
I really like this. It is more “kid friendly” because there are no exposed blades.
Try a hairdryer next!
“flinging it out like children on a merry-go-round” Those merry-go-rounds sound much more exciting than the ones around here.
If one oriented the fan to exhaust over the upper surface of wing and fuselage, the airflow would increase the venturi effect, and add to the total lift of the wing; example, Ekranoplan. With two fans side-by-side, one exhausting over each wing root, the total lift could be increased considerably.
this is great! thank you. very inspired.