Hi, i saw on Ebay that actual drone motors cost very much. As i am building a drone completely from scratch , i would like to use some life hacks e.g. turning pc fans into motors. Are there any people with that kind of experience that could point me to some direction ? What size of propellers to use, what fans to use?
A computer fan can't generate enough thrust to lift itself - they are designed to shift large quantities of air slowly and quietly,
Drone motors are expensive because a drone needs a motor with a very high power-to-weight ratio.
This guy proved me it is possible.
Plus i would use ducted propellers. That would provide more thrust and efficiency.
Take a look at drone motors here: www.hobbyking.com instead of ebay.
laisut: This guy proved me it is possible.
I did not realize you planned to take the motors out of the computer fan and use different propellers. It's an interesting idea.
My comment that a computer fan can't lift itself remains true AFAIK.
Still wouldn't work unless you're talking about a tethered drone, which isn't much of a drone. They'll never get enough thrust to carry any control circuitry and power source.
laisut: Hi, i saw on Ebay that actual drone motors cost very much. As i am building a drone completely from scratch , i would like to use some life hacks e.g. turning pc fans into motors. Are there any people with that kind of experience that could point me to some direction ? What size of propellers to use, what fans to use?
They are very cheap, not very expensive. An industrial rated version would be $100 or more.
You cannot possibly substitute a fan motor and get anything like the power/weight ratio of a decent RC brushless motor. Remember you need a lot of power to hover (much much more than to fly a plane), and your motors have to hold up the weight of everything, battery, frame, electronics as well as themselves, and have a comfortable performance margin (x3 or so) for manoevring.
That video shows the motors can barely lift themselves alone, certainly without a margin of performance.
One of the things that RC brushless motors have over fan motors is that they use NdFeB magnets which are much stronger than the ferrite magnets used in fan motors.
Ever wondered why quadcopters didn't exist before neodymium magnet motors and LiPo batteries were available? Because you need that power density. A quad can use 50 to 200W just to stay in the air.
There are a bunch of 2212 motors and 2208 motors on ebay for about 5 dollars us. They will get a pretty good sized multirotor in the air. What do you consider expensive?
According to my experience with radio controlled airplanes and drones anything less that $150 won't fly, and if it does it certainly won't be well.
The green and black ones here fly well, with streaming video available even on the larger one, can have first person view on your phone. http://www.toysrus.com/family/index.jsp?categoryId=67715146&sr=1&origkw=drone https://www.youtube.com/watch?v=Vo8CbLwWQR0 Piloting skills on the other hand ...
These cost about $50-60 in parts each (not factoring in transmitter) , Although they look like a pile of crap ( they look better in the air) , they both fly quite well, The big one uses those cheapo 2212 motors. The little 250 sized one uses 1808 motors. All the motors were about 5 dollars a piece.
Even the little quad can fly with over a pound of payload. The big one can carry all kinds of stuff, never really tested its max.