Bicopter with Betaflight, pt. 0
Frame kit as it arrived from banggood. It did include servos, even tho they said it would not.
Aaand next project is in the works! This time I’ll be building something completely different and new to me. A bicopter. I have no idea how to wire it, how to configure it or how will it fly. I hope I will learn all those things in the process of building this funny looking thing.
This is what I wrote to instagram on 22nd of June. I had literally no idea what I was going to get into but I just wanted to build a bicopter. I had never even seen one live but I knew it would be cool anyway.
When I tried to google how to build a bicopter with modern hardware like F722 flight controller and newer betaflight I couldn’t find much anything at all. It seems like no-one has built one like after an era of KK2 boards. Or at least people haven’t posted anything online even if someone has built one. So I had to do everything from scratch.
Empty frame with just PDB and main power cable. From the beginning I wanted to use two batteries in parallel in order to maximize the flight time. There’s 3300uF cap on the main powerline, seems to be enough. You can see already from this picture that I designed and 3d-printed some parts for this frame.
Build
Soldering this was little pain in the ass since I had to build the PDB/FC stack *before* putting it into it’s place and before I could solder much anything to the FC. With little planning and patience I managed to do it pretty well I think. Video transmitter is mounted on the side and antenna is on the bottom for minimal interference with frame itself.
GPS-stack
I’m kind of proud of this design. GPS fits well on top of the frame and the base also provides protection for the capacitor. I had to put ~4mm standoffs between two parts to make room for the ESCs.
Test flight with 5″ props.
Problems and what to do next
- FPV camera is fixed to the frame, when the body rocks back and forth while the copter moves it makes flying in fpv pretty much impossible.
- Comparison of different propeller and battery combinations, looking for longest possible flight time.
Parts list
- HJ-2502 250mm bicopter frame
- Racerstar 2207 BR2207S Fire Edition 1600KV
- Racerstar RS30A 30A Blheli_S OPTO 2-4S ESC
- 600TVL 2.8mm Lens 1/3″ 16:9 Super Had II CCD Camera
- MG90S Metal Gear RC Micro Servo
- Cooltech RFASB PPM SBUS 2.4G FASST Compatible Receiver
- Matek FCHUB-6S Hub Power Distribution Board
- Matek Systems F722-STD STM32F722 F7 Flight Controller
- Beitian BN-880 Flight Control GPS Module
- DYS MI200MW Pigtail VTX25mW/200mW
- DIY pagoda2 antenna
Betaflight CLI dump of my current setup.
Hey nice work,
I have a F7 from Matek too but my Servos are moving when i increase the Throttle can you maybe help me. I use the same betaflight update like you.
Thank you
Hi Ogifrosch!
I don’t have the bicopter with my right now but if I recall correctly this had something to do with a stick deadbands. I remember increasing those might help this issue. I don’t think that solved it completely either and I think my bicopter still does this but after getting on air it corrects this behaviour.
Good luck with your build and sorry for late reply!