This is my attempt to build a ultralight 1s 85mm whoop. I should have go with a diamondf4 elrs, and save another 2 grams, but worked with i had at the moment. So i've stripped off the board connectors and soldered the motors on the board (to remove board connectors and motor plugs saved a gram).
Tested with gemfan 2023 and hqprop 51mmx2. The first one provided more punch, at expense of add about 2.5 grams and is less efficient. The later provided 5:30 of flight time with a 450mah 1s, which is not so bad. It's raining too much now, then i'll fly outside later.