Here is another attempt at a lightweight build that runs on 18650 cells. AUW = 223g. This one was based on Dave C's micro long range / Rekon35 2S quad. I flew it a couple times on the 18650 cells I had around the house. It flew pretty smooth but only for a couple minutes each time. I use Caddx Vista digital VTX in all my drones which was the challenge for a 2S quad. I used a Pololu 9V step-up voltage regulator with a 33uF/16V capacitor. This regulator needs at least 2.7V to start but can deliver 9V down to 1.3V. The video was crystal clear even after the drone dropped to the ground from low voltage. I have a bunch of Molicel 2800mah/35A 18650 cells ordered and will update this post when I'm able to get some longer flights on the new batteries. I'm really into designing/building these drones that run on 18650s. I can keep them charged and send a drone up at the spur of the moment. I'm probably going to iterate on this one to make it a little more compact but easier to assemble. It was pretty tough to get nuts on the FC. I'm also thinking about getting a cheap CNC router for Christmas so that I can start cutting some parts from carbon fiber versus printing everything. This frame is printed from PETG and it took about 6-1/2 hours. It printed pretty well but it was a lot of work pulling out all the support material and cleaning it up.