Meet Big Bertha and the Boys


Hi Diy'ers


Thought I would share my latest Project with you, and keep a running log of our progress. Your comments and suggestions are most welcome!


The Team :

Wessie van der Westhuizen a.k.a Clowns Hobbies

Gustav Kuhn a.k.a Groundpounder

Dave Thomas a.k.a Darth Vader


The Mission :


To build a UAV capable of a payload of 5Kg, to stay in the air for 1 hour.


The Equipment :


Airframe : Lanyu Primary 100, wingspan 2.54m (100")

Engine : E-Flight Power160 engine (will eventually be a 50cc Gasser)

Batteries : 4 x 4400mah 5s Lipo wired to 10s 8800mah pack

Prop  : 22 x 8 wood

ESC : Hobbywing 100A HV

Servos : 6 x 9kg Digital Savox servos

Radio : Spektrum DX8 2.4GHz


APM 1280

Xbee Pro 900Mhz

GoPro Camera

5.8GHz Video TX/RX

15" Video Monitor

Toshiba netbook

17" Monitor

250A Deep cycle battery

1500W Power inverter

4 Port Quad charger

lots and lots of wires ;-)


3689423334?profile=originalWe fitted Rubber anti-vibration mounts for the Gas engine, when we changed to Electric it made mounting the motor easy, so we left them on.


3689423198?profile=originalNot show on this picture, is that the APM is mounted on 2 Layers of Align Gyro Gel.

The Batteries go into the front hatch compartment, the other battery you can see is a 3 Cell 3000mah pack that powers the Avionics via a 8A Hobbywing Regulator, and the Video TX directly.


You can also see th 6" Dubro inflatable wheels we fitted so we can land on just about any terrain.


Our Ground Zero is a nifty foldable table and seats, Easilly transported.














Our second test Patform is the ST Models discovery. This plane has proven to be a Brilliant choice for UAV work. It flies the waypoints REALLY well with the stock PID setup.


3689423428?profile=originalBoth Planes are fitted with downlinks. At some point we will get some SkyWalkers for comparison.


We Fly at Two Sites in SA. For safety reasons we ALWAYS fly at registered flying clubs.









3689423505?profile=originalThis is the discovery mission in 20km/h wind. Hope to get Big Bertha to follw tracks like that as well soon.

3689423557?profile=originalThis is the mission we are running at the moment with Bertha. All waypoints are 100m AGL

2011-09-04%2009-36-37.tlog  is the Results for last weekends flying. It contains TWO missions, but enough data. You will see that I need to do some PID tuning here, as well as move the Pitot-Tube away from the leading edge of the wing, where it is getting weird readings in the turbulent air as it seperates.


Below is the RESULT of the last mission. The aircraft successfully hit every waypoint - eventually, sometimes after some considerable waypoint hunting.

3689423528?profile=originalWell, thats a start, let us know what you think, We will add more info as time goes on.











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  • Oh Before I forget :

    I need to acknowledge and thank the DIYD dev team fror all the hard work coding, troubleshooting, assisting on the forums, and making our lives easier as amateur droners. Special mention must go to Chris, Jason, Jordi, and Jani, for you have all assisted me personally at some point or other. But the greatest accolade in my book must surely  go to Michael Obourne. Without your excellent interface in mission planner it would be alot like installing Linux over your windows platform with no command line knowledge. A well written, intuitive easy to use interface makes even the most complicated back-end system a pleasure to use.  Well done lads, and thank you again.

  • So the April Fools fly wen well. REALLY well. I am happier than I have been in months with my APM's performance.

    Conditions :

    Sunny, 14km/h to 20km/h wind.

    Temp 26 dec C

    We had some problems at first getting the APM to get out of RTL mode, but after a restart, it was fine, and the mission continued. We flew 3 Circuits, and if you look at the attached picture, you will see that the 1st 2 tracks are almost perfectly superimposed. By the last Blue track, the wind had increased, and we had a bit of signal dropout, but the long leg is still perfectly aligned with the previous flights. This repeatability is what gives me the most hope and pleasure.

      3692387063?profile=originalLet me know if you are interested in looking at the logs, I'll be happy to post them.

  • We flew Big Bertha today, and after we sorted the vibration issues, she followed the track so well.

    Secret to mounting APM in a vibration intensive environment :

    • Put downa 3" layer of foam, anti vibration rubber will be even better.
    • Attach the APM to a nice heavy object. We used an old RC car battery pack
    • This provides inertia and vibration dampening.
    • Cover the package with another layer of foam
    • lightly strap it all down to nothing can move.

    The secret really is to "disconnect" the APM from the airframe so it "floats".

    Gustav's idea, and it works really well

    Will post pictures and the log tomorrow.

  • Trials with the electric motor have been successfull, now we have re-fitted the Gas engine. Flying tomorrow..

    Vibration is a killler. Managed to fashion an anti-vibration setup which seems to work well

    will Report back...

  • Oh, also in the process of building an electric aircraft that can fly 100 Km, with some reserve......

    Hovering the Quad above the wing to aid the glue in drying :-)

  • The Discovery with a 2200mAh pack gives about 12 minutes @ 55 Km/h......


  • @Cliff

    Im getting 20  minute flights at the moment with 30% reserve left in the battery.





  • Very nice setup, interested to hear your flight times with electric.

  • Moderator

    Great stuff!

  • Wessie  - well done. Looking very good.



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