My UAV platform

[skogsvargen]

I started out trying to build a INU, but grew so tired of the slow progress. I want to start testing things and not only doing things in theory. So i skipped a few steps, bought a FMA Copilot and built myself a plane.

This is what it looks like so far. There is still much work to do but now i have a platform for my experiments. It is my own design, but the wing design i borrowed from a .40 trainer wing with a little extra span. It has about 5 litres of available volume to fill with cool stuff. Test flights will show how much power i will need to keep it flying and how much weight i i can add without loosing to much performance.

Some data:

weight 2100 grams (4,6 pound)
span 165 cm (65 inch)
wingload 58 g/dm^2 (19 oz / sq feet)

motor axi 2820/12 with 11/5,5 prop
3s2p 4500 mAh LiPo

As soon as the snow melts away it will be ready for its maiden flight as a R/C model.

Regards from Magnus
Stockholm, Sweden

[icebear]

Nice plane Magnus!
Keep us posted on the flight tests etc.
Some mild spring weather is heading your way - we already have spring here down south :)

/Bjorn

[Tom Harper]

Good job, Magnus - let's see it in the air.

[ijustwant]

I agree with Bjorn! Nice plane. I was thinking of building my own plane as well. But now i have began my project with a Senior Telemaster. Bought a Pico-pilot NAT from U-Nav.

The weather here in South of Norway is more on more like summer these days so maybe my Telemaster is airborne by easter :-)

[Blue Sky]

A very well thought out design!
Beautifully constructed.

-Dave

[vector_vortex]

Looks good,
Looks a bit like a aerosonde,
http://www.aerosonde.com
let us know what length flights you get from the electric setup.

Have Fun

Joel

[kd7ost]

Yep,

Nice looking plane. Anxious to hear how it flies.

Dan

[skogsvargen]

Thanks for all positive comments!
Next step is radio and motor installation. I have to decide if i should wait with the Copilot just to keep everything simple to start with.

It may take some time before it makes it maiden flight, but as soon as it fly, i will keep you updated with the results.

/Magnus

[kd7ost]

If it were me, and please understand I'm not trying to tell you what to do, I would fly it without the co-pilot or any enhancements to start with. I would fly it as a strict RC plane and put it through all flight evaluations to tweak the throws, thrust etc until it was flying just like I wanted. Then I would integrate the co-pilot into it.

The co-pilot can do things that prevent you from getting a solid feel for its raw flight characteristics. It could mask or compound flight problems keeping you from seeing what the plane does and prevent you from getting it worked out. Even in the disabled mode it will effect your flight trims. I wouldn’t even wire it in on a new design airplane until you are happy with the way the plane fly’s. Then work it in after you get your plane flying the way you want it to.

I have two of my own designs that use the co-pilot and some GPS equipment. I always took a one piece at a time integration approach. It keeps things manageable for you as the designer, builder, test pilot and all the other rolls you take on getting it flying well. You've got mixing in the Cathedral or A tail that needs to be dialed in first as well as roll, pitch and yaw rates. I suspect you will have pretty sensitive pitch to start with.

Dan

[skogsvargen]

Dan,
Thanks for the advice. I think you are right. I will leave the copilot aside but I won't be using any of the mixers in the radio that i can't use with the copilot. Ailerons on one channel and a Veetail mixer for the rudder/elevator mix. If the weather permits the plan is to fly next weekend.

/Magnus

[RaptorAP]

For some reason I love the plane Magnus!!
Whatcha think, Dan?
Love the inverted Vtail, Hmmmm... I have another fuse...
Mike

[kd7ost]

Lets see another one Mike. :D

I'm not getting very far or very fast with my Pegasus2. Work got really busy but thats OK.

I'm playing with a parafoil at the moment. I'm hoping to get something put together to take on the road with me that packs in a little box.

Dan

[libelulamodelos]

nice plane Magnus, excelent choice tail booms and pusher config ..

[skogsvargen]

The snow is gone and the sun has dried up the field where the test flight was planned to take place. No wind and clear a blue sky made yesterday to a perfect day for flying.

First flight...
...was almost ending in disaster. Right after take off we experienced huge glitches especially at the throttle, but the pilot made follwed the check list :) and made a 180 degrees turn and landed with the wind. Logged flight time 30 seconds. Plane intact.

We revired the receiver antenna and made a new attempt.

Second flight...
...was beautiful. The Captain at the controls and me as Copilot.

* The plane behaved much lika a trainer.
* Level flight at 40% throttle
* The A-tail had to small rudders to turn with rudder only. I think i will go for
aileron turns with my AP-solution. Or make larger rudders...

We logged 10 minutes in the air. Plane intact

After the first flight i decided not to push my luck. I will install a stick antenna in the plane before next flight.

The rest of the time was spent on testing my GPS telemetry system...
The system consists of a Basic stamp, a GPS and a small radio modem. All it does at the moment is transmiting data to my PC for logging. It fits nicely in most planes and everyone at the field wanted to measure their planes speed. :)

Some data:
* Range more than 300 meters. I have not tested any further
* Transmits position, COG, SOG and altitude
* Power directly from the R/C transmitter

I was most impressed by the GPS altitude measurements. The graph below shows a precision i didn't think was possible. Whats your experience in GPS altitude measurments?


I hope to receive more pictures later in the week...

[skogsvargen]

Just some additional pictures...

[toxicmouse]

skogsvargen, can you get VDOP (Vertical Dilution Of Precision) information from your GPS? I get it in the $GPGSA, that should give you an indication of the accuracy you should get for altitude.

[RaptorAP]

Very nice, glad to hear it flies well. Im still eyeing the inverted V tail. I still havent put booms on my latest project, a larger 60 sized Grey Ghost.
Looking like a great platform.

[s2e3s2z2]

Does anyone make ARF kits one could purchase?

[Gary Mortimer]

Now I don't want to sound silly....

But with the exhaust pointing forward would'nt you suffer from a slight reverse thrust.

Maybe thats just a demo fit and the arrangement will be slightly different in the end.

G

[RaptorAP]

Nah, the exhaust comes out and runs back to the rear, its low enough the oil residue doesnt really adhere to anything, I usually use an exhaust deflector it adds to the redirection. Ive done this on previous models, stole the idea from Dave Jones at AUAV.
Mike

[skogsvargen]

I have made some additional flights with my plane and it sems to be working OK after adding a stick antenna to the receiver.

I mounted a camera and took some pictures and as soon as i feel a little more comfortable flying it i will start to test the electronics.

I will continue my efforts to build an autopilot but since there are good progress in the projects here i will try a different approach. I have decided to rely on a two way radio link and do most of the computing on the ground. The plane will get a heading to steer and in case of lost signal it will return home based on the last knonw heading home. More on this later.

You can follow my efforts on my wiki at:

http://wiki.leijonborg.se/index.php/Main_Page

Regards

Magnus

[Mark Harris]

Any chance we can get some video of it in the air?

[kd7ost]

Congratulations on the build and the flying. You've done a great job. Those landing shots do look like a mid motor design. Sweet. :D

Dan

[skogsvargen]

My plane is still alive and flying, but only under radio control. The radio downlink is working so I can monitor position, speed and altitude, but no autopilot yet.

I have been using it to take some photos and that works perfectly. It can fly really slow with flaps and do steep low speed landings as well. Only drawback is that it requires some space and for take off and landings.

I attach some photos from my neighborhood outside Stockholm, Sweden. The picures are a bit unsharp due to low light.

/Magnus