This is part 2. To avoid ending up trapped in the twilight zone read Part 1

Hey Guys! First, I have to confess. I lied... It did not started by looking and drawing on an autocad 2009 computer screen.

It started with some delirium about designing a different kind of quad. I talked about it to my partner and we both agree that variable pitch quad was something to consider. Before many of you start screaming about complexity I would like to give you my position about it.

The venerable 4 motors / 4 ecs quad is the way to go for simplicity, affordability and quick fun.

It is the perfect platform for what it is intended for. Some are dreaming about a quad entering a contest like the outback challenge but we all know that autonomy is not what a quad is made for.

Also, redundancy is null in a traditional quad. Loose one motor and zap it goes. Loose a prop and zap it goes again. Lets pushed it further, what would it be like to have a quad to do 3D flying like a TREX 450 helo? And maybe a very different kind of 3D flying? What would it be like to have a quad flying with the speed and the autonomy of a plane? What would it be like to have that kind of quad doing it with absolute redundancy and also with total safety to surrounding peoples and infrastructure?

That is where you will say I have got crazy. My friend and I have the intention of proving you right about this craziness by proving you wrong about the limitations of a quad.

One last word, this one about KISS (keep it stupid simple). It is my opinion that you can KISS a simple design by design, OR, you can KISS a complex system by a simple design. Both result should be targeting a different mission and be good at it. DIY does not keep one from making it a complex but efficient system. Alright, money can do that so that is why we also added that requirement to our project.

You can now see that we are indeed crazy and some of you probably are to. Those one will understand that a guy can't sleep over some crazy ideas and some times find the solution in the middle of the night. That is what happen to me when at 2 o'clock in the morning I saw 4 penny's standing side by side on the night table. ZLAMM ! Here is the simplest way to have 4 rotors turning by opposite rotation pairs. You all know that it is a requirement for yaw control of a quad. Many have tried to figure it all and it was there, costing only 4 cents.

So now, talking about affordability... What looks just like a quad arm but with a variable pitch head? Many of you again thought about that but a few tried it. You are right, an helo tail boom seems to fit the profile. And what is the most common helo with easily available, affordable parts? The trex / clones family. Just check on eBay, it is crazy what our Chinese friends can do for almost nothing. If you want some quality, you guys from the US are pretty good at it although a little bit expensive. But hey ! you get what you need for the place you need it.

Ok now for my Fans Club, here some more details... Please understand that the next video clip is showing an hand drilled crude prototype never intended to fly. It was merely a proof of concept for a gear train and also maybe a dream catcher. If this is bothering you and your are disappointed, I will stop right here, just let me know...

E-mail me when people leave their comments –

You need to be a member of diydrones to add comments!

Join diydrones


  • somebody already built such a thing, it's nothing new
    but he uses only 1 big motor it is about 3 meters in diameter

    but you wrote, you want something fast like a plane for autonomy
    well, my quad can fly about 100km/h i think that is fast enough
    it it better for autonomy than a plane, so why such a complex thing like you are going to do?
    if you want redundancy, just build a hexa or an okta copter (wich will fly, even if you've lost 3-4 motors)
    tell me the reason
  • I like this idea and would like to hear more as you come to figure things out
  • IDEA, if an engine fails, or even 2 engines fail and this is what we think it is... rotating/shifting rotor direction as well (rollers), wouldn't it be possible to swing the blades into an X config with the 2 working motors at the top lowering the frame gently down? or if A and C failed swinging into a + with the 2 side engines running, dagh just my stupid imagination.
  • rollers are obvious to roll all 4 engines, he said speed of a plain which implys forward tilting engines or atleast thats what it meant to me
  • I still don't see how you solve the redundancy and yaw control issues, can you explain?
  • Mario

    Brilliant - you not a little worried about the gear noise (?) - what material have you hobb'd the gears out of??

    Meldin 5000 (engineering plastic) - great for small gears
  • photos!!! photos!!! :) :)
  • Hayee yaa...u heard it from me. I guessed it right..all way along. You are cool mario, not as cool as the 8bit mario..still u rock. keep riding cowboy. Nice work.
  • Waiting with more anticipation than the DVD release of Inception
  • Variable-pitch quadrotor. You have my rapt attention.
This reply was deleted.