Shrediquette - the award-winning multirotors by William Thielicke

Recently, I discovered some small counter-rotating propellers that I didn't know before. I ordered some and did some tests. The red 4x4.5" props look really good, nice thin airfoils and a good precision. During the tests, they made the least amount of noise, and are currently my preferred ones. The performance of the 4x2.5" props is even better, but they have a pretty terrible sound and seem to be less balanced. Both propellers outperform the AirAce propellers, but this is not really a surprise because the AirAce have a smaller diameter and more blades. What is also interesting is the weight of the propellers. A propeller with a lower weight potentially has a lower moment of inertia which is beneficial for the control loops: AirAce: 2.1 g 4x2.5": 1.5 g 4x4.5" : 1.3 g So this is an advantage for the 4x4.5" propellers, especially because the weight of this propeller is more concentrated to the center, which should further lower the momentof inertia. ...

Here are two images of the current status. Green is the favorite colour of my girlfriend ;-) . There will soon be an additional one in purple I fear...

I just realized, that I haven't yet posted an image of the PCB that I am using since half a year in the BOLT S|2 and soon in the GEMiNi. It is really small and weighs around 1 gram. It contains the minimum number of parts possible + 3 LEDs: Thermoforming the canopy also worked pretty well once I found the correct temperature. I tried Vivak (PET-G) and black Polystyrol: The chassis should be finished very soon, I am really looking forward to putting everything together...!

Yesterday the motors arrived from hobbyking (Turnigy C1822-2100KV). As usual with small motors, the shafts were all way too short to attach a propeller. Three-bladed props do not really work nicely with the provided prop-saver... Hence the original shafts had to be removed. It was pretty hard to exchange all motor shafts, as they have a very tight fit with the bell, and they are additionally glued with cyano. Some "nail polisher remover" and some heat helped a lot to remove them. The quality of the motors is really good. I did some tests and compared them with the Robby Roxxy 1815-25 that I use in a similar copter (the BOLT). Both motors have the same size and the same weight, Surprisingly, the turnigy motors have the exact same performance as the much more expensive Roxxy motors. The increased KV number leads to an increase in the peak RPM and thrust. The endurance with these motors will be around 8 minutes (the aerodynamic efficiency of the GEMiNi will be hi...

Still waiting for the motors and ESCs, I was playing around with the canopy design: Shrediquette GEMïNï from W. Thielicke on Vimeo .

Holidays are copter days... I spent some time during holidays to design a new FPV hexacopter. It will be equipped with the AirAce props that I used in the BOLT and some cheaper hobbyking motors (2200 RPM/V, ca. 15 grs.) + turnigy Plush 6A ESCs + a 1000 mAh 3S lipo. I also designed a canopy for the copter which I will print in 3D, thermoform from 0.5mm plastic sheet, and eventually laminate with carbon fibre. The propellers are tilted 10° forward in order to decrease the angle of attack of the copters body in forward flight, which will hopefully decrease the net aerodynamic drag in fast translational flight. I am hoping that this copter will be able to fly even faster than the BOLT. The GEMiNi is slightly larger, the max. dimension is 315 mm from propeller tip to propeller tip (diagonally). I will use the CCD-Killer camera, and an Airwave module for video transmission. The CCD-Killer is still my favorite camera in terms of image quality and exposure control vs. weight and size. ...

RC Flight Control 3/2012 title page In the latest issue of the "RC Flight Control", there is an article about my BOLT Y6 hexacopter. The article is about how and why I designed the copter and there are some details about my previous copters. Paul again shot some nice photos, one of them is on the title page. A preview of the magazine is available here: RC Flight Control PDF Preview 3/2012 At least in Germany you should be able to get a copy of this magazine in every larger newspaper store.