Back in 2007, I decided that I want to learn how to use microcontrollers and how to work with electronics and control loops. I needed an interesting project to keep my motivation high, therefore I started to make multirotors. In all the tri- and hexrotors, several revisions of a very tiny custom flight controller are used. The electronics, software and hardware are built completely from scratch.

These are my main achievements in the 'multirotor world' (click the images for videos / links):

2007 Initiated one of the very first open source flight controller projects
2009 First-ever automatic indoor flight, guided by a standard webcam
2009 First-ever mobile phone controlled multirotor flight
2010 Smallest trirotor design
2010 Automatic position hold
2011 First-ever 'dead-cat' hexrotor design
2011 'Best Operational MAV award' from Dutch police
2012 First-ever tilted rotor racing quad design
2013 Licensing one of my designs to Team-Blacksheep
2015 First-ever tilted body racing quad design
2015 First-ever vertical arm / tilted body racing quad design
2016 Invention of the camera tilt compensation ('fpv_mix_degrees'), now used e.g. in Betaflight
2016 First-ever 'aero pod' racing quad design
2017 Invention of side-force-generators (SFGs) SFGs
2018 A new method of inflight propeller performance testing Proptesting
2018 2nd place DroneClash 2018 Counter-Drone Competition DroneClash 2018
2019 Development & design of a large wind-measuring drone Optokopter
2019 2nd place DroneClash 2019 Counter-Drone Competition DroneClash2019