Developer

ArduIMU Quadcopter part II (mini)

Hi all,
I have finished my second quadcopter with ArduIMU. This time is a "mini" version with only 28cm from rotor to rotor and has the new Jordi´s magnetometer integrated!.
This tiny machine is fantastic, with a great stability. Look at the hands-off part of the video inside house!!
Very funny :-) Video:


Specs:
Motors: 1811 2000Kv 10grams brushless motors
Props: standard 5x3
ESCs : Turnigy 6A
Batt : 2S610 Lipo
Weight (RTF) : 180grams
Again it´s a very cheap and easy setup. Because I use standard propellers I mounted left and right motors with some twist. I´d really love arduIMU flat hardware...


Look at the PPM output Rx, Is this a new 2.4Ghz receiver form DIYDrones?
No, it´s a "lighweight" (4.1grams) mix between Spektrum AR6110 Rx and Jordi´s PPM encoder. This is nice for DIY projects...


The code is improved from the old version. This one has the magnetometer integrated so now we don´t have drift
on yaw axis, better implementation for the D term on the PID controler (more responsive to user inputs), same safety improvements, fast ESCs update rate (166Hz), new PID tunning...

But this history had an interesting lesson for me... The prototype you see here are really the second one, the first one was a dissaster... (flys bad...)
Do you want to know the "small" difference between them? This:


For the first one, I use an U shaped aluminium arms to save some weight. Well this shape is very bad in torsion and generates a lot of vibrations. This vibrations saturate the gyros (our gyros are quite sensible on vibrations because the low internal resonant frecuency). You could see here a graph of the gyro output value vs Throttle and you can see clearly the effect...


I change the arms to the square shape (8x8mm) and problem gone!! Perfect stability... :-) Vibrations are our enemy (Lesson learned)

Here is the new source code: Quad1_mini_20.zip (see notes.txt inside)
Schematic (conections): Photo1 Photo2
Old post (first version) here

New ArduPilot Mega will be a perfect platform for Quad´s also, so stay tuned...

Jose.

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Comments

  • Hi, Roberto
    I am a Spektrum user (2.4Ghz) so I was wandering how I am going to get PPM (composite) signal out of the 2.4G receiver. Can you offer any insight here?

    Thanks
  • Hi, Roberto
    This is my spec.
    * motor : Turnegy 2204-14T
    * ESC : turnegy plush 6A
    * propeller : GWS5030(front,left,back), 6050(cut 1cm both blade because each motor different power)
    If you have lucky you have same power motors delivered^^
    * battery : 3s 800mah apach
    * landing gear : polycarbonate cnc cutting like mikrokopter landing gear.

    Yun
  • Yun,
    "Alive ArduIMU Quadcopter" looks good!
    Can you tell (links) us which
    * motor,
    * ESC,
    * propeller,
    * battery,
    * landing gear
    used on your platform?
  • Alive ArduIMU Quadcopter
  • jose used this prop:
    http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10033
    ESC is Turnigy plush 6A right.
  • Jose Julio,

    Thank you for sharing your excellent project with all of us!
    I want to build a copy of your platform. I searched HobbyKing for motor, ESC and propeller.
    Can you confirm if the following components are correct?
    18-11 2000kv Micro Brushless Outrunner (10g) ($7.99) (This is out of stock, which other one can you recommend?)
    TURNIGY Plush 6A /.8bec/6g Speed Controller ($7.58) (Is this the right one?)
    Which prop you would recommend (URL please)?

    Alternativelly, do you think any one of the these Motor+ESC+Prop combos can be used?

    Can you show how did you mechanically mounted two (or three or four) aliminium bars under/between the blue color central panels?

    Is there any body on the group who also build their ArduIMU based quadcopter? Can you share your construction experience with me/us?

    Thx
  • Thanks Thomas and Jose.

    74157 is SN74LVC1G3157DBVR in TI

    Yun
  • Developer
    Yun, I agree with Thomas, it´s a multiplexer to choose between GPS or Serial port TX. You can live without this component if you are not using GPS (also you can connect the GPS directly to the Serial port in the future...)
    Jose.
  • 74157(cc5r marked) is in ArduIMU board but it's 6 leg.
    but 74157 is 16 pins.
    is ther 6pin 74157?
  • Admin
    Yun,

    The 74157 is a multiplexer. It is used to allow the MCU to select between either the FTDI input or the GPS input on its Rx input.

    Hope this helps.

    Regards,
    TCIII
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