Multiplex FOX as UAV

This is a private project, yet another integration of my autopilot with a test platform. Basically everything I ever used as RC model is now flying by itself.

The FOX is really unflyable in RC mode when the motor is below 30% throttle, autopilot handles it much better.
I believe it could be the smallest _classic_ layout winged _outdoor_ UAV in the world, the reason is that small UAVs are typically flying wings in order to have larger wing chord what plays major role at low Reynolds numbers.
It is not fun to fly in manual mode because it stalls for any reason. But it can be done and all landings are a spectacular crash when plane bounces like a ball from any obstacle it finds, spiralling around Z axis.
It has surprisingly good 31min endurance and 50km/h cruise speed, what because of its size feels like it would be flying at 100km/h. It is so small you lose it from view if you turn in the wrong direction, I cannot tell its orientation from more than 250m away. From 400m it is a tiny dot that you lose forever if you blink. It is also inaudible from more than 150m away so flying it is a real thrill: 'is it still up there?'.

Yet another UAV on rudder only I have made, but there are others with full house mechanics. No, airspeed sensor is not necessary for this airframe but would make tuning so much easier. It would be also the first thing to break all the time, so I am using Pitot tube only on a few specific birds.

This plane is fully autonomous and can navigate waypoints even 20-25km away as endurance permits, RC controller is used for trimming, testing and backup control.

It is driven by FLEXIPILOT, developed by me in ancient times.
Not for sale, not a gift. But it works and scares the neighbours, 'because it can be done'.

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  • T3

    No, I have used only the plane symbol.

    After watching the results from the script, decided my own in C++ made a year or so earlier was better structured for my purposes.

    Even forgot from where it came, pteryx.dae from standard decoder didn't fit the plane shape so replaced by anything I had at hand.

    For example, ther reason for not sharing my decoder is that it also outputs for several professional GIS tools and that integration took around 6 months of work. Consequently, I cannot share without leaking important technology that is ignored by 99% of the audience but abused by the rest.

  • Developer

    Nice to see you are using my open source. Did you happen to use my python as well as the Aircraft Models to create your Googel Earth representations ? (because I have some bug fixes).

    MatrixPilot Flight Analyzer Google Earth Plane


    Krzysztof Bosak's displayed Google Earth Plane (identical).



  • T3

    I brought my autopiltot to the sale point around late 2008.

    I am not selling because I was denied of startup capital.

    I am not sharing for free because I am a free man.

    I am not publishing much because I got more creative projets.


    Use of FOX for a first project is higly disrecommended, the smaller UAV the more difficult it is below certain size.

    Larger platform-easier tuning. Motoglider in the range 1.2-2.4m weight 0.5-3kg is the way to go.


  • Dear sir,

    I am wondering about your auto pilot.  Do  you build them from scratch and are you selling them.  My project is very similar to yours.  I am light years behind your expertise but wanting to learn.  I am wanting a platform that can be programmed to run a course and take pictures or live feed transmit.  I would prefer to be able to communicate with it in case I want a different angle of an object to get that perfect picture so FPV is probably necessary.  So far I am having trouble getting advice that is not contrary to what I have learned here on DIY so far.  I want as small a package also because I enjoy wild life photography and it must be transportable .... perhaps even packaged to fit in or on a back pack.  Your work is very similar to what I am looking for.  Any help is appreciated.

  • @Tumba


    Is he/she on here?



  • T3

    @Tumba 'then your FOX is smaller. :-) ... I will not cut my balsa - wings... :-)'

    Noononooo the bird looks beautiful as it is ;-)

  • @ Krzysztof Ok, 479 mm ... then your FOX is smaller. :-) ... I will not cut my balsa - wings... :-)

    @ DaveyWBB ups... I never creates config files for a quadrotor... There the paparazzi team can help or a friend of mine at the Bremen University, he is working with paparazzi and q-rotors...

  • T3


    Not that it matters, but somehow, my FOX since the second flight or so has 1cm shaved, it is 479mm +/1

    Your UAV however has much more other equipment.

  • @Tumba


    Can I pick your brains on Paparazzi? I need to create some config files for a quadrotor (Lisa/L Aspirin IMU).





  • Maybe this 500 mm FOX is not the smallest classic layout winged outdoor UAV in the world. :-) In 2008 I was flying a 400 mm Paparazzi classic layout winged outdoor UAV. http://www.hs-bremen.de/internet/einrichtungen/presse/mitteilungen/...

    We presented this at the European Micro Air Vehicle Conference in 2008 (Including a paper). Later I was flying a 490 mm classic layout winged outdoor UAV, see http://diydrones.com/forum/topics/presentation-30-x-40-mm

    But your FOX is flying really well.


    Best regards


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