Model Lightweight RC Plane

[nye]

as a uni project we hav to make a lightweight airplane running on renewable energy..does anybody hav any ideas or sites tht might b useful??and also, a site where i can easily get the schematic or circuit diagram for a RC control system for the plane..

 

[3v0]

as a uni project we hav to make a lightweight airplane running on renewable energy..does anybody hav any ideas or sites tht might b useful??and also, a site where i can easily get the schematic or circuit diagram for a RC control system for the plane..

I do not think you gave us all the info.
What parts can you buy assembled or as a kit ?
Can you pull the RC electronics from an existing toy ?
Can you use off the shelf servos ?
How many channels are required ?
What is your budget?
How long do you have to build it ?
Does it have to fly ?
Who gets to crash it ?

You could use solar cells to charge a battery pack an use it to power a class of RC airplane known as a park flyers. Google "park flyer"

If you need to build you own electric motor I recall a site where they are reworking HD motors

 

[nye]

they hav jus told tht we hav to build the plane..im not sure whether we can buy the parts or hav to assemble it on our own..i suppose to make it lightweight we hav to do it on our own right?
RC electronics, i was tihnkin we can make it on our own or buy it from a model or electronic shop..can u suggest anything??
no of channels...hmm..sill not sure..
budget is about 2000 australian dollars for the whole thing..
we need to have the solar panels on the wings..there'll b a brushless DC motor, and a lithium battery to giv the bursts of power needed for take off..they also told tht a special featuer will b its low speed and low drag..

 

[Nigel Goodwin]

Buy the RC gear, it's not expensive - and you're not going to build anything as cheap, or with as good performance.

 

[3v0]

they hav jus told tht we hav to build the plane..im not sure whether we can buy the parts or hav to assemble it on our own..i suppose to make it lightweight we hav to do it on our own right?
RC electronics, i was tihnkin we can make it on our own or buy it from a model or electronic shop..can u suggest anything??
no of channels...hmm..sill not sure..
budget is about 2000 australian dollars for the whole thing..
we need to have the solar panels on the wings..there'll b a brushless DC motor, and a lithium battery to giv the bursts of power needed for take off..they also told tht a special featuer will b its low speed and low drag..

So the challenge here is the aerodynamics of the airplane.
Start reading up on park flyers. There are some DIY sites out there.
They will be the closest to what you are building.
To keep weight down keep it as small and simple as possible, rudder only if allowed.
Try to determine which motor is best suited for your needs.
Buy the electronics or salvage them out of a RC toy. Keep weight in mind.
About the only thing I would build if budget permits is the airplane itself.
The airplane comes first, Maybe a design that is more of a powered glider.

You need to ballance the size of the airplane and motor.
Spend a few days comparing what exists on the web.
How much money will be left after the solar pannels?
Did they say anything about wingspan on length?
Again how long do you have to build it ?

This sounds fun.

EDIT: You need to start looking at solar cells/panels to find the ones that
provide the best power to weight ratio.

If the 2K is the final cost of the plane you may be able to buy parts to try/compare
and not report the unused stuff.

If this is a team effort split up the work load.
Have one find the best motor, another the best solar cells etc.

 

[evandude]

I don't think building an airplane that can fly under power of on-board solar cells is going to be as easy as you might think... solar cells are not very efficient, and usually not very lightweight either... Even with some expensive, lightweight, efficient ones, I still think it'll be pretty tough...

I know it's been done before, by like a research team or something, but I've never seen it pulled off by those with limited money and no experience...

Good luck!

 

[HarveyH42]

I remember seeing some "flexiable" solar panels some place on the web, seemed like the output was similar to glass panels. I had no interest at the time, was looking for something rugged, that would hold up well in Florida.

Just mentioned it as something to look into, should be lighter and less likely to shatter in a crash. Could conform to the curve of the wings.

 

[audioguru]

You will need the fortune of money that NASA spent for their solar electric plane. Its wings were covered in solar panels and were so long that they bent from the weight of them. The plane barely flew.

An electric Park Flyer model plane uses rechargable batteries that could take a week to charge from a solar panel that is a reasonable weight. Then the charge in the battery is discharged in a few minutes.

Maybe your plane will "fly" a few seconds like the Wright brothers first powered flight. Then it sits in the sun for a few hours before its rechargable battery can power it for a few more seconds.

EDIT:
You can cheat a little. Make a huge glider with a small electric motor. Then fly it where warm air is rising from the ground to keep it flying. The solar power will be fake.

 

[philba]

I'm not quite a negative as the rest but there are definite challenges. Even if that puppy never gets off the ground, a lot will be learned, provided you do the work yourself.

I would definitely look into gliders as they are designed to be extremely efficient. Figure out the payload maximum. Figure out how to live inside the weight budget.

good luck and report back when you've made some progress.

 

[Thunderchild]

hm I say do try to make it a fare size, that was you will possibly have a lower weight/size ratio, you could use a prop on each wing and knock out the ruder by controlling the two motor speeds for steering

 

[3v0]

Gloom and doom. That Nasa plane (Pathfinder-Plus) was a monster and carried a payload of cameras and transmitters, flew to nearly 10,000 feet.

Random musings.

All this thing has to do is come down slower then what the other people build.

It has a lot to do with scale. Weight is the big problem. That is why ordering a selection of parts to test etc is a good idea. The RC reciever from a toy may be lighter then the more rugged units used by the hobby types. You could still use a more powerful transmitter if more range is needed.

This thing should only need to fly once or twice.

According to the OP the plane is to use a battery to get airborne but must then run off the solar cells. Maybe use some lightweight rig to drop the battery after takeoff. Hook the release to the rudder servo so that the battery will drop the first time the rudder turns left or some similar contraption.

When designing the plane you need to think a lot about center of gravity. The plane has to be balanced. You want to design the plane and all it contains to balance without adding weight.

Maybe use a lightweight boom to hold the motor wings tail and RC gear. Figure out how to make the lightest wing possible and still hold the solar cells. Figure out what the choices are.

You may find that the solar cells are more of a burden then a help. IFF this is the case put just enough cells on the wing to turn the motor. This will make for a lighter plane and it will glide further then the heavier ones.

 

[HarveyH42]

The origional post was more about schematics for the R/C portion of this project. Do you really need to build this from scratch? Got a hunch it would be a major expense in time and money to build something small, lightweight, and sufficient range for flight. Transmitter for my helicopter (Blade CP) is over $50, $10 for crystals, 4-n-1 Rx/controller $70... Probably cheaper for a glider.

Anyway, little power would be need to steer the plane, and running the prop only to gain altitude, shouldn't need much of a battery. Wondering if when you cut power to the prop, will it continue to spin the motor during flight, and generate some power? Added to the solar panels and small battery, might work for a while...

 

[audioguru]

Make an "over unity" electric airplane. Use one motor to propel it and use a second motor with its prop in the airstream as a generator for the propulsion motor. Then you don't need a solar panel nor a battery.

 

[dknguyen]

hehe, you should have chosen a boat (a sailboat! or even a solar car) that runs on renewable energy rather than a plane. The only thing I can really think of is a bunch of solar panels on the ground powering a laser beaming at the plane...but that's pretty exotic. I'm not sure if you can get solar panels that provide enough energy and are light enough to go on a plane.

THe problem is you say you are using LiPos...unless they were charged in with renewable energy, your plane is nothing more than a regular RC plane!

 

[Sig239]

RCGroups.com!!

I have found the RCGroups website to be a great source of information for everything RC. It has been around for a while, and has LOTS of info.

 

[3v0]

I have been had.

There seem to be people that post asking for help just to see what we come up with. I think this is one of them.

 

[audioguru]

I have been had.

Yes. Where are they going to find ordinary electronic stuff in their country? Shoot down an American satellite?

 

[nye]

this is true..i DID NOT JUST ask u guys for help for nothin..I AM a first year uni student so this was the first time i had the time to come online since i posted it..we hav to submit our proposals by friday, and i still hav to meet with the other memebers of the group..besides, abt audion guru's comments sayin, 'where am i going to find the stuff??' for your information, sri lanka has quite a few places where u can find electronic stuff..we're not some primitive country as u think we are..and btw..im not in sri lanka anymore..im in AUSTRALIA!!!!!!!otherwise why do u think i was talkin in AUSSIE DOLLARS???it would b appreciated if ppl were a bit more tolerant...we have no choice and i chose this project..

 

[Thunderchild]

Make an "over unity" electric airplane. Use one motor to propel it and use a second motor with its prop in the airstream as a generator for the propulsion motor. Then you don't need a solar panel nor a battery.

haha that can't work the generator drag will be higher than the prop power as it is not 100 % efficient and if it were nothing would happen anyway because they would balance

 

[3v0]

this is true..i DID NOT JUST ask u guys for help for nothin..I AM a first year uni student so this was the first time i had the time to come online since i posted it..we hav to submit our proposals by friday, and i still hav to meet with the other memebers of the group..besides, abt audion guru's comments sayin, 'where am i going to find the stuff??' for your information, sri lanka has quite a few places where u can find electronic stuff..we're not some primitive country as u think we are..and btw..im not in sri lanka anymore..im in AUSTRALIA!!!!!!!otherwise why do u think i was talkin in AUSSIE DOLLARS???it would b appreciated if ppl were a bit more tolerant...we have no choice and i chose this project..

Perhaps you should change your location.

I am not convinced, a $2000 budget is over the top for a U project/contest. Too much for the U to fund and way too much for most students. All the more preposterous for a first year student.