Flying robot ?!

[TiagoSilva]

How can just 2 fans lift a battery pack and the entire periperals
?? Is there any equation that converts the Fan Helice Size + Fan Rotation = Weight Lifted ???

It could be most helpfull to build a gadject such as this !
Tks

 

[Electric Rain]

I can't really help you too much here. But I've thought about that myself. All I have so far is a very strong, small heating element with a fan above it blowing into a large balloon. Just like a hot air balloon. But no gas, and it actually has two things keeping it up. The fan blowing air up into it, and the heating element making that air hot air, and as we all know, heat rises.

Anyway, that along with four small fans on the sides to control direction and an RF reciever in it is all I've got. Oh, and maybe an ultra-sonic setup on the bottom to keep it at a pre-determend hieght. What does everone think?

Rain

 

[bmcculla]

I saw a small flying robot an one of those tehcnology shows on TV. It had 4 fans arranged in a square adjusdting the thrust between them kept the thing level. I'm not sure what sensor setup it used but you would need some sort of level sensor to adjust the thrust of the 4 fans.

As far as the lift equasion you'll probably have to find a Mechanical Engineering Fourum for that one :wink:

 

[Oznog]

I believe that's the DraganFlyer:
**broken link removed**
Also just search eBay for "draganflyer".

It rotates 2 rotors in the opposite direction from the others to avoid net torque. I imagine it can even correct slight imbalances by shifting the load from one pair of rotors to the other to create a corrective torque reaction.

They do sell an optional camera.

Also go to eBay and search for "electric helicopter" or "dragonfly helicopter". Lots of neat stuff available today, and at a bargain price!

Any propeller gets more efficient as it gets larger. I think they may use the same size prop though, the DF has 4 of them but only flies for 5 min (and costs $900!). The single rotors claim 10 min, and that's on a NiMH pack, the DF only gets those 5 min with a higher capacity/lower weight lithium ion pack. But the maneuverability that comes with 4 rotors as well as the gyro is pretty cool.

There are also some really fun cheapo toys, though many don't actually have any useful controls in the remote (ON/OFF). I got a Blackhawk 3 rotor which is fully controllable, but corded. On the plus side, it doesn't run down and you can use it for hours on end. It has no torque compensation on purpose and the whole body spins. It uses an infrared sensor to orient its spinning self by looking for the infrared transmitter on the remote control. The power/control cord has slip rings to make the electrical connection without twisting up. I had endless fun swooping it back and forth, it was really difficult to keep stable but that was half the fun. Eventually a little plastic pressfit pinion gear broke, so sadly it's down for the count.

There are probably a lot of RC groups who can tell you exactly how much weight a particular rotor can lift. But the lifting capacity, as well as the run time, is VERY limited. So you'd probably be restricted to the lightest camera made, lots of fun but don't count on a quality picture. Gas helicopters can lift much more and run much longer.

 

[Oznog]

Oh yeah- there's also the coaxial AirScooter, which was designed as a manned ultralight helicopter but they started selling little RC models of it. With 2 counterrotating props, you don't need a tail to compensate for torque. It just uses a swash plate to deflect the air coming down to turn it one direction or the other.

**broken link removed**

 

[happydud]

I can't really help you too much here. But I've thought about that myself. All I have so far is a very strong, small heating element with a fan above it blowing into a large balloon. Just like a hot air balloon. But no gas, and it actually has two things keeping it up. The fan blowing air up into it, and the heating element making that air hot air, and as we all know, heat rises.
Rain

You would really only need the fan to inflate the balloon, in that case. I've done my fair share of hot air ballooning, and once the balloon is inflated, you only need a bit of hot air now and then to keep it up.

That being said, I'm sure there would be a more space/weight efficient way to inflate the balloon.