Over at Hackaday, a quadcopter made from ewaste.
"It’s pretty obvious that the main rotors are PC Fans, 140mm in this case. Normally, these wouldn’t be able to create enough lift to get out of their own way except the on-board 24v Dewalt cordless tool battery bumps up the fan speed to 15,000 rpm."
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Update on my quest to make case fans work for quadcopters, I took apart a random case fan I had laying around and created a custom motor bell using the stock magnets from the fan. So far, I have yet to try high voltages, but at stock voltage, I have props running at hardly significant speeds. The fan has no PWM, just straight 12V dc, so I will be desoldering the coils from the onboard brushless controller and rewiring it for an ESC soon. Hopefully I will have much better results then. I'll post videos soon, I'll keep you updated!
@Gary: Do the fans have to be unmodified, or can I steal the motors and make something that at least lifts itself? ;) This might just be challenge accepted.
oh boy.. I was thinking about using four vacuum cleaner motors and a 12V inverter, then reverse the AC polarity and create thrust instead of suction... but I realized that I have a thermal problem getting the heat away from these motors at 15k rpm :-) .. uuhm...
BTW I'll just be hiding behind the concrete bunker when those motors spin up to 15K RPM!
If one of these fans doesn't provide enough power to lift itself, just add more of them until they can. I see a dodecacopter on the horizon.
I have lots of PC fans (larger server ones as well)...but are they efficient enough?
I mean I know that technically, the fewer the blades the more efficient, but this just looks too cool not to work!
These 7 bladed PC fans are engineered to move a large volume of air rather than provide lift, but really now, isn't that the same general idea?
Sounds like we need an April first contest:
First one to actually get a quad made from old exhaust fans to actually fly - maybe a realistic time limit like 1 minute or so (before the fans burn out).
And I think we should give a special prize to Rob's stick and twine copter (I'm sure it can be done too).
Maybe just most outrageous quad!
Time limit of 1 minute hover video verified.
Jack I know this is something you could win with one hand tied behind your back.
Best, Gary
Brilliant - loved this...if my son sees this he will cannibalise my Ubuntu server and his PC for the fans....:)