CK Wing Tailsitter VTOL

thingiverse

First, I am not affiliated with or financially supported by CK Wing manufacturer. I was looking for a flying wing to convert to VTOL (tailsitter and Y3). After searching for sometime, I found CK Wing (https://a.aliexpress.com/_mqsCQwK) is a good candidate: it is light (foam) and has a large wing area; it has very low stall speed and excellent gliding performance, easy to fly (see Andrew Newton's youtube video about CK Wing) ; well designed and sturdy; and only $37 with free shipping on AliExpress. I tried a few motor mounts found on internet first as I do not know the airfoil of CK Wing to start designing. It turned out this one (PLA+ used) fits CK Wing well: https://discuss.px4.io/t/motor-mounts-for-duorotor-flying-wing-tailsitter-like-caipiroshka/431 (thanks Ivan!) I added M3 screw hole on it. Two M3*35 mm screws with nuts are used to attached the motor mount to CK Wing. The screw hole is located ~ 5 cm from the leading edge, and ~ 10.5 cm from fuselage edge (see pictures). Hot glue is also applied. Once installed, you may notice the motor mount is not aligned with the leading edge, slightly pointing downward (see pics). It works fine and may slightly increase angle of attack. Motor (2): ReadytoSky MT2204 2300kv ESC: Zeus 48A 4in1 ESC (you can use two separate ESCs. I am using 4in1 ESC because it will be convenient to convert to Y3 VTOL later) Flight Controller: Pixhawk 2.4.8 (you can use any FC compatible with Arduplane). Arduplane param file is uploaded for your reference. Please note PID parameters of the FBWA mode are not optimized but there is no issue to fly as you can see from the video. Thanks ArxangelRC for sharing his param file for Arkbird VTOL with me for reference. Propeller: uxcell 6045 (6X4.5, one CW and one CCW) Battery: OVONIC 4S1P, 1550 mAh, 100C (convenient for Y3 VTOL later) CG: marked under fuselage. Please refer to AliExpress or Andrew Newton's video for CK Wing assemble instruction. Here are CK Wing tailsitter QHover test and VTOL maiden videos: https://youtu.be/sRMgEkXW6uk https://youtu.be/rRM8MTDrFnQ One important thing: When take off, you should suddenly increase throttle to 50-70% to lift CK Wing VTOL up to the air so that FC can efficiently control QHover. If you slowly increase throttle, CK Wing may just fall down on ground.