120mm FPV frame for 8520/F3 Evo

thingiverse

This is my take on the fpv micro quadcopter frame. I have experimented with many designs, went through lots of iterations and I would like to call this the final one. I didn't invent the wheel, since this is an already existing design, remixed by many, but I made some small changes to the source design that worked out pretty well for me. ####**What does it fit** - F3 Evo 2.0 brushed flight controller (the cheap one) - 8520 brushed motors (racestar, or generic, doesn't matter) - AIO cameras (like the Eachine TX03) - 65mm props ####**The size** I wanted to use 65mm props, since they provide around 20-25% more thrust than the 55mm ones. They fit on a 110mm frame, even on a 105mm one, but the center part (flight controller tray) of the frame blocks valuable area under the propellers. I did some measurements, and using the same design I saw a 10% thrust increase with a 120mm frame over the 110mm one. And it weighs less than a gramm more. ####**The body** I always had problems with the flight controller moving around after crashes, which messes up the calibration, or rips out wires. Now the tray has these clamps the flight controller can slide under and on the other side it is pushed down by a pillar from the top. Rock solid. The camera mount is simple, you can zip tie it onto the platform and it has enough overhang to keep the lens secure, which is crucial with these small AIO cameras, because it's really easy to break it off. It fits the Eachine TX03, don't know about the others though. As for the motor mounts, I went with a little lip on the bottom so the brushed motor doesn't fall through. The lip is big enough to hold it and also small enough not to pinch the motor cables when you push them in. At the bottom of the engine holder opening you will find a small closing, which acts as a cable guide, so it wont sag and get under the frame, then get pinched if you land on something hard. If you have you first layer a bit squashed it will print as one, but if you push your motor all the way down, it will detach easily. ####**The material** As for the material, I don't recommend anything other than ASA/ABS. The first ones I printed with PLA, and even after the slowest crashes I had random chunks breaking out of the frame. ####**Tips** I recommend the cheap Turnigy 750mAh 35/70C battery for this build. It is as cheap, or even cheaper than the chinese ones and perform much better. Not only it has the actual capacity, it can provied more juice, thus giving your quad more thrust. You can always pick them up from the hobbyking site with very cheap wordwide shipping.