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 jose i was wondering maybe how much will it be to get one of those from u already built?? i also have a new fpv gear with monitor if u want to trade one of those for all my fpv system with 7"monitor please add me n write me back ok..right now i have a ar drone that i had for a week now but still need to buy a ipod touch to fly it i been useing mybother iphone..
  • Hello:
    I´ve all connected and the arduimu programmed, but I think there is something in the ppm encoder-rx couple that don´t work properly.
    I´ve configured the tx like an airplane and connected like Jose Julio said, but when I accelerate the engine don´t do nothing. Any idea?
    Thanks
  • Nice work Jose! Why you take only 28cm from rotor to rotor?Why not less
  • This is main code "Quad1_mini_20.pde"
  • I download Quad1_mini_20 code,but I not see main code where the main code??
  • jose!! u doing great stuff. keep up the good work.
  • how to set Transmitter ?
  • jose, why didn't u have to calibrate the magnetometer?
  • hello Cholo, it is necessary to follow the method of José to find the good PID.
    it is necessary to be very fine on these reglages, me I still do not manage to have reactions sharp of my quadcopter like that of José, I seek the reglage fin.le choice of the propellers is significant too.
    good luck
    dody
  • hi
    anyone knows what are Kp_ROLLPITCH and Ki_ROLLPITCH values and do I have to tune theme also ?

    cholo
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