I wanted to learn how to build a bicopter, so I built one!

This was in interesting journey, I saw this frame on banggood and thought to myself that hey, that's something different and I want to make it.
Without giving things much thought I ordered parts for this. I saw from the pictres that this would probably fit 7" props so I chose a low kv motors. 1600kv might not be optimal for 4S but they work.

Configured this to fly with betaflight which was also probably a bad idea because betaflight was kind of broken when I tried to configure this. I had to submit issue on github but then gevs fixed it for me and gave me a working version of the firmware to get it up and running. Running this on Matek F722 FC, works very well and I'm kind of a fan of their products I guess.

Lots of resource remapping and servo mixing later I got it to work and now it flies pretty well. I have tried bunch of different props and I think these 7" biblades are the best ones. 13min flight time and stable control.

Lot of the parts on this are custom made and 3D-printed. You can get them here:
https://www.thingiverse.com/thing:3078387

The FPV aspect of this however is, at least for now, completely useless because the camera is fixed to the frame which keeps rocking back and forth.

Other problematic thing are the servos. I use cheapo MG90S servos which are not the best in any way. They have a lot of slack and they could be more precise. Some real heliservos or servos with feedback would be great.

Short flight with 7" props.

At the beginning you can see that because I have used trims it tries to correct the position with low throttle and almost flips over. Usually I just punch it to the air when this doesn't happen but because the person filming this was standing kind of close to it I didn't want to do it.
Forgive me my bad landing.