Starting this world

[sansolo]

HI,
i'm from Brazil and with some engineering friends we want to build a model to fly Recife - Fernando de Noronha (540 kilometers) over the sea. We are now looking for autopilot sistem. What equipments do you recomend? We just need something to stable the altitude and heading. Nothing expensive, dont need autolanding, take off or throtlle control. I dont know nothing about UAV's, so I need a list with all the equipments easy to use.
Thanks,
Ricardo.

[kd7ost]

I might recommend the Pico Pilot from UNAV. http://www.u-nav.com/

Take a little time to navigate the site. It's not the most intuitive but is likely going to be the least expensive way to do your mission with off the shelf technology.

You would be looking for the Pico Pilot NA

Dan

[sansolo]

thanks kd7ost I was thinking this one. Just two questions more: 1º what system should we use to know the position in the GPS with range of 540 kilometers. (how much :p ). 2º Do you know about someone who have used an OS 1.20 surpass for 9 hours?

[kd7ost]

thanks kd7ost I was thinking this one. Just two questions more: 1º what system should we use to know the position in the GPS with range of 540 kilometers. (how much :p ). 2º Do you know about someone who have used an OS 1.20 surpass for 9 hours?

Wow,

That's ambition. :eek:

I don't understand your first question. Do you mean how can you track your GPS position and UAV from 540 km? I don't know how to if that is the question. Maybe using APRS from the HAM radio world.

I think even with a 4 stroke engine that’s an awful lot of glow fuel for a 9 hour flight. I think you would have trouble doing it with 3 or 4 gallons. Couple that with the possibility of a glow plug failing and you're sunk. Literally and figuratively. I would use a 4 cycle gasoline engine with a spark plug and magneto engine to keep cost down and reliability high.

Dan

[sansolo]

no, this is not an huge ambiton, today is having a race of birds (800km in 5hours) huahuahua. track the airplane is not the most important thing, about the engine maybe an eletric engine. we have solar panels, if we discover how to use that to charge the lipo batery, the engine problem will be solved.

[Unyon]

I may be wrong, but I thought LiPo batteries were not designed to be charged while discharging. Better look into that (I heard it somewhere in rcgroups, but I dont have a link for ya)

[sansolo]

but we can have one battery discharging while other battery is being charged. shi** I dont know how to say: we change the battery that was discharging and charge it, and the other that was discharging, charges.

[JettPilot]

The battery does not know if the total system is producing current to a motor or not. It either sees a load, or it sees higher voltage and is being charged. I dont see how there would be a problem charging while a motor is running.

That being said, a solar setup would be very heavy, and not practical for long overwater flight. They barely keep sailplanes aloft. A glow engine is not reliable enough to fly that far, and they use so much fuel, that you could not carry enough fuel to do it anyways. Either way, you will end up in the water and lose your plane :mad:

JettPilot

[DiveBombDave]

A glow engine can be dieselized and generally gets better duration off the same amount of fuel (model diesel), and eliminates the glow plug. Turns a larger prop slower.

www.davisdieseldevelopment.com

It would have to be designed as a flying fuel tank, and I'm not saying it'd work - that's a pretty serious distance, and I can't do "gas math." :)

Dave

[d_wheel]

The model here:

http://www.memagazine.org/contents/current/features/amodel/amodel.html

Flew for 38 hours and traveled 1900 miles on Coleman lamp fuel. It's an interesting read for anyone interested in GPS guided flight.

Later;

D.W.