Open Source Airframe

CTOL UAV 2.0

Our little robot in the UK

Specifications

  • Length 1.4 meters
  • Wing span 1.8 meters
  • Chord 30cm
  • Uses counter-rotating motors (redundancy, speed, balance, no torque)
  • Uses remote servos (wing flaperons, the tail surface) for more storage and ease of repair
  • Empty weight 5.5kg
  • Thrust is 12kgs
  • Max load 12kg (lift at 100mph/160kph is approx 12kg)
  • Endurance is between 1 to 4 hours with existing specifications
  • Wings can be repositioned to change CoG for large payloads
  • Stringers located on the fuselage to carry the wing, landing gear and other modules
  • These channels also hold internal items like the motor via bulkhead rings, for quick changes
  • Fuselage can carry liquids (same diameter as 2L bottle of cola)
  • Can be launched by rail and use parachute recovery
  • Can be fitted with front wheels for conventional landing in rough fields
  • CAD files are from Solidworks

Design Files

You can download the CAD schematics and the bill of materials here:
http://www.openrelief.org/documents/CTOL-UAV-current.zip

Please note: The above link and information refers to the Second Generation of the OpenRelief airframe. If you want to download the latest copy of the Third Generation beta please visit our blog.

The People Behind The Airframe

Edward Strickland

Edward Strickland

Edward Strickland

Edward Strickland, a gentleman with a degree in aeronautical engineering, experience with Open Source Auto Pilots and 7 years experience with QinetiQ and UK MoD, has lead the development of the OpenRelief airframe.

The OpenRelief airframe is an expansion of Eddie’s research regarding commercial Vertical Take Off and Landing (VTOL) drones. You can review an interesting overview of his VTOL focus on YouTube. You can visit Eddie’s profile on DIYDRONES to learn more about his day-to-day work on drones and open technology.

The Organisations Behind The People

Oldham College logoWorking with the OpenRelief disaster relief project, students from Oldham College on the BTEC Level 3 Mechanical engineering course have been contributing to the development of airframe parts for the Open Source Unmanned Aerial Vehicle.

Students have been working;

  • On a new design of wing which has internal load space for payloads.
  • Stronger landing gear to suit a longer airframe.
  • A unique installation of the avionic and power units within the wing.
  • Stronger modular tail and control system.

It is expected that the airframe will be shipped from Oldham College to an experienced UAV user for initial flights in the UK, leading to further rigorous testing in the Australian outback with a final destination of Japan for humanitarian flight testing over the Tsunami affected disaster areas.

History

The first version of the OpenRelief CTOL-UAV airframe was released on the 6th of July 2012. You can read the original release announcement here and download the version 1.0 CAD files / bill of material here. It is based on a Conventional Take Off and Landing (CTOL) airframe developed for VTOL testing purposes.

The 2.0 airframe was released at LinuxCon Japan on the 31st of May 2013. It features the following refinements:

  • An updated tail section to simplify and strengthen the airframe
  • An updated front fuselage to strengthen the airframe
  • An updated rear fuselage to strengthen the airframe

License

The airframe is licensed it under the TAPR Open Hardware License 1.0.

Notes

Please note that the propellors are located at the front of the plane, which allows for a simple build and flight quickly, but does introduce the potential issue of damage on landing. There are various ways around this like deploying a parachute, flying into a net or rods which stop the propellor at 3pm position. However, the default airframe is intended to simplify the build process and does not include these features.

It is also worth bearing in mind that small scale aerodynamics produce large drag components at low speed that continually limit range. Be conservative about endurance in your local environment.

You should also be aware that testing shows even 2 to 3 flights can take a real toil on the system at this scale. This means that the lifetime of an airframe may be limited, especially if it is not checked and maintained frequently.

Development Gallery

10 Responses to “Open Source Airframe”

  1. Mike McRoberts June 3, 2013 at 12:15 pm #

    What is the purpose of this craft? What is it going to be used for?

    • admin June 4, 2013 at 12:19 am #

      Hi Mike! You can see an overview of our goals on the “About” page of this site:
      http://www.openrelief.org/home/about/

      In essence, the aircraft is being designed as a flexible, light reconnaissance system for disaster relief.

      • Jan Piotrowski June 17, 2013 at 7:02 am #

        Hi,

        I am a journalist interested in this project and potential benefits to disaster relief. As there are no contact details on this site, could you provide me with some way of getting in touch with someone involved in the project?

        Thanks.

  2. Perry Ismangil June 6, 2013 at 2:19 pm #

    I am not a drone expert, so please bear with the questions: Any particular reason a fixed wing design rather than a helicopter or quad copter design?

    Thanks!

    • admin June 7, 2013 at 2:23 am #

      The simple answer is “range” :)

      The fixed wing gives us a great deal more range. With a gas engine the current Open Source Airframe should go several hundred kilometres. With a dense energy source like kerosine Edward estimates that 700km and upwards would be possible.

  3. Matt June 12, 2013 at 7:16 am #

    Hello!

    I’ve done some model aircraft building and flying, I’m so impressed by this design! It’s very well thought out! I’m curious about the avionics, have you seen the UAV that was used by CanberraUAV in the UAVOutbackChallenge.com.au? It seems like you could almost plonk their ardupilot/raspberrypi system into your airframe and make it do a lot of what you want. After all their system is designed to autonomously locate people and deliver supplies to them.

    Nice work!

    • admin June 26, 2013 at 2:37 am #

      Hi Matt! You are quite right. Actually, we envision people doing precisely that, and using excellent open source software like that produced by CanberraUAV to create open source drones. Our own testing is targeting ArduPilot and CanberraUAV tech, though naturally you could use almost any autopilot and ground control system.

  4. Christian Ledermann July 2, 2013 at 2:19 pm #

    Great Effort, congratulations :)

    your airframe would be excelent for http://conservationdrones.org/

    • admin July 3, 2013 at 1:33 am #

      Naturally we would be delighted to discuss interaction. If you have a connection, just let us know.

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