This project was started in , electronics and control loops. Because I always need a cool project to learn new things, it was clear that something that can fly had to be built.
The project started as a "tricopter-only" project, but as I wanted to build smaller vehicles with more payload capacity, I decided to make some quadrotor, hexacopter and Y6 hexacopter firmwares too. My main interest is to build very small MAVs that fly as good as larger ones (or even better) and that can be controlled by wireless video link. I also experimented with autonomous flight in GPS-denied areas (video), and with GPS assisted autonomous hover (video).
-- William

Contact: Shrediquette @ g m x . d e --- All content published under CC Attribution-Noncommercial-Share Alike 3.0 Germany

QRC5 design

The QRC5 incorporates some ideas that I had when I was designing the GEMiNi and the HEXO+. First of all, it's not a hex- or trirotor anymore, it is one of my first quadrotors... Personally, I think quadrotors are a bit boring. But there are many FPV racing events coming up, and I am sure that most of them will have several different regulations and limit the battery voltage, the amount of motors or the rotor diameter. The most 'standard' racing copters are quadrotors, they have 3S batteries and 5" props. I am sure that they will get their own racing class. I would like to be able to compete with them, therefore I decided to design a copter for this standard class, even when I am not the biggest fan of quadrotors or racing rules and classes.
The Shrediquette QRC5 fits the 250mm quadrotor racing class
Tilted propellers have become popular since the GEMiNi was presented, and in my opinion they really have an advantage. The aerodynamic drag is reduced quite a bit in fast forward flight. And, also important, the drag is increased in slow flight and during braking. This part becomes important on racetracks with sharp corners.
The QRC5 does not really have tilted propellers, but a tilted body (which is very similar). When only the body is tilted, there is little vertical offset between the propeller disks, which seems to be advantageous for the flight control.
The body is tilted 30° backwards, leaving the propellers on a relatively similar plane
The arms that connect the motors with the body are flat plates that are aligned with the dominant flow direction: Below the rotors, the flow will be 95% perpendicular to the rotor disks, no matter how fast we fly. The flat plates have very little drag, which will increase the maximum flight speed. Each of these plates are made from a three-layer sandwich (glass fibre, end grain balsa, glass fibre). This results in extremely rigid and lightweight arms.
Top view: The flat arms are parallel to the main flow direction
I'll again use the 'CCD-Killer' CMOS camera by Fatshark. For me, this is still the best camera, even much more expensive CCD cameras don't give such a great image. The camera is tilted 13° up (with respect to the propellers).
The CCD-Killer sits between the arms


  1. Do you also plan to (have this) produced?

  2. Well, I don't know, if someone feels like he could do it, then we would find a solution. I don't have anyone yet that is interested in producing it. But first, I have to find out if this works like expected...