RC helicopter payloads

On 9 Aug 2005 20:12:22 -0700, snipped-for-privacy@gmail.com wrote in :

Stop right there and meditate a bit.

You've already left the arena of ordinary AMA models (dry weight of 55 pounds) and entered the field of Experimental Aircraft.

Helicopters need a LOT of power to lift heavy loads. I'll bet (totally amateur guess) that you'll need an aiframe in the 200- to 300-pound range to safely carry that kind of load. That's a big machine and a big rotor. I don't know of any commercially available equipment like that (I told you I am an amateur, didn't I?), so that means at the very least that you'll be paying big bucks to someone who can machine the parts for you or for the company who builds the bird for you.

Down in the AMA arena, we get the benefit of mass-production so that it's not inconceivable that you could buy a chopper capable of lifting as much as 15 pounds for a few thousand bucks.

You might want to google the "aerial robotics competition." The first link is:

They've been doing stuff like this for years (not with your payload, however). You might look for the university nearest you and see if you can pick their brains about how they control their aircraft.

That's how it looks to me from where I sit.

Sounds like fun.

Way out of range of off-the-shelf equipment. Commercial (relatively inexpensive) transmitters are designed for 1 mile or so. You might get lucky and get two miles out of them, but not at 300', I suspect.

For 15 miles, you'll have to go to different frequencies and higher-power equipment. I have the lowest possible HAM license and I'm pretty sure it's not good enough to do a project like this. You'll need excellent feedback from the machine to fly it 15 miles away by hand or else you'll need an autopilot combined with a GPS system: .

Are you sure you need a helicopter? You can get better payloads with an aircraft. See the Aerosonde site: .

For a 60-pound payload, you'd need a plane at least twice the size of the Aersonde, but it's not impossible (especially if you don't need a lot of speed).

Many people have done what you want to do. It's not impossible. It's just difficult and expensive.

You should also anticipate getting some attention from the Feds. This kind of design could be used as a tool for terror as well as a tool for agriculture and other legitimate commercial purposes.

Maynard Hill flew an 11-pound (wet!) model across the Atlantic using an autopilot and GPS navigation. The military has all kinds of Remotely Piloted Vehicles or Unmanned Aerial Vehicles. Google UAV to see some slick sites.

Turbine engines are now being developed for RC helicopters. They may help get your payload aloft--but they need to carry a lot of fuel, too. Aviation is a series of tradeoffs.

Marty

| I am currently trying to decide if an engineering project that I had in | mind would be possible to complete in the time that I have. | I wanted to experiment with creating an unmanned aircraft to deliver a | payload from point a to point b. Ideally I would need a payload | capacity of maybe 60 pounds

You're not getting this out of any stock R/C helicopter. Even six pounds would require a large helicopter.

| If I can't find something with a high payload capacity I might be able | to get a laptop or even a gumstix computer and eliminate the need for a | UPS

A UPS? You want to have the helicopter carry a (desktop?) computer and a UPS to power it? This would be fun to watch!

Seriously, this sort of thing has been done. I've seen shows on the Discovery channel where there were competitions along these lines. For computers in the helicopters they used itty bitty computers like Palm Pilots or other PDAs. Even a laptop is too big. They genreally used WiFi or something similar to talk to a laptop on the ground that did the serious computing.

| This project is more a proof of concept and a personal exercise than | something that I will be receiving credit for, but I am very interested | in making it work.

It's not cheap or easy. I don't doubt that the Discovery channel show setups I saw cost at least $20k each ...

| Also, what is the typical range for an RC helicopter? And what is the | maximum altitude? Would expecting 15 miles at 200-300 feet be too much?

200-300 feet is no problem. 15 miles is. The R/C gear we use only has about 1.5 miles of range, and that's assuming line of sight. (And that's far more than we can see at.)

To actually fly 15 miles autonomously I'm guessing that might upset some people. I don't know if the FAA would care or not -- at that point it's more of a UAV than a model. More practically, your helicopter would need a much larger fuel tank than normal. And you'd better have that engine running just right so it doesn't die on it's own ...

The president of one of our local flying clubs is involved with an aviation program at the University of Kansas where they're developing UAV protocal and methodoligy using the Yamaha RMax platform.

You can see pictures of the 125lb. RMax and get a little more information at the club website:

There are pictures of Tom flying the copter inverted, which is pretty gutsy. I've heard the price tag of an RMax is in excess of $100,000, but I honestly have no real idea.