2S Ultralight 88mm 2" Micro for Apartment Cruising - Ultralight built from remnants of Rakon Heli 76mm Brushless Whoop. This is meant for flying outside of my apartment where being light and quiet is most important. In the end I ended up creating a pretty fast and nimble machine too.

The idea for this build came after the ESC on my Rakon Heli 76mm brushless whoop burnt up. I was mostly flying around my apartment courtyard with it but disliked the 41mm bullnose props as they were a bit too loud and it felt difficult to do any acro with the whoop. I found the 88mm frame on Amazon and decided to adapt it for an ultralight build. The frame is drilled for a 20x20 FC stack but I wanted to use a 16x16 to keep the weight down and leave just enough room for an AIO camera/vtx combo inside the frame. To mount the 16x16 ESC/FC I used double sided tape with some holes cut out for airflow/cooling. In addition, the frame is meant for slightly larger motors so I countersunk the motor holes and only used 2 bolts to mount the tiny D1103 motors. I had a bunch of 1S 220mah LiHV gumstick batteries from my whoops that I wanted to re-purpose for this frame as well, so I configured 2 powerwhoop connectors in series for 2S capability (just like the RKH 76mm whoop uses). The FC and camera both support OSD so it's pretty nice to have a Betaflight OSD on something so small and light. My previous whoops did not have an OSD so this has really been a great addition.

The result is a pretty nice flying machine. It only weighs 41 grams! and it's takeoff weight with batteries is only ~52 grams! The larger 2" props are really nice and stable and much quieter than the bullnose props it had before. It has a ton of power for the space I'm flying in and is super nimble. I especially like how much improved the roll/pitch/yaw authority is with the more aerodynamic frame and larger props. With default betaflight PIDs it was pretty bad but some quick tuning made it a real joy to fly. The only thing I disliked at first was the quality of the video link. I think my Wolfwhoop P-1 came with a bad antenna so I replaced it with another dipole and that resolved my issues.

Flight time on the tiny 220mah batteries is ~4 minutes, or 3:30 if I fly more aggressively. It can hover for 5 minutes no problem. I think the small motors are good for the weight of the craft as punch outs are great, but I do notice that it's lacking a bit of torque with the larger 2" 4 blade props. I'd like to test out 3 blade props but need to find some that will push-fit onto the shafts without bolts and I'd like a quiet pointy end-of-prop design.

I'm really happy with this build and would build it again. Next time I might consider DYS BE1102 7800KV or maybe HLY S1103/KV7000 motors for easier motor mounting, maybe a little more torque, and better prop mounting solutions.