Birdbrain RC Exocet 5

By CarbonRain on May 07, 2020

19  197  5

So the Fortress builds proved that I can consistently cut a decent box frame thanks to the thickness tolerances being awesomely tight on my carbon sheets these days. Since I (and nearly everyone!) have a lot of free time at the moment, I figured I'd go back to an idea I've had rattling around in my head for a good year or more - a box frame with a plus layout.

It's no secret that I do love a plus quad (got 7 in my current fleet!) - I love the idea of box frames too though, so what better way to overcomplicate things by combining them. At the same time, I've had good experiences with elevated rear motors on quads, as a means of getting the stretch frame benefit without needing a stretch frame size - so naturally I went for the trifecta of weirdness, a box plus with vertically staggered motors.

The carbon parts came together in CAD pretty quickly, having decided right at the start to use a 20x20 stack because I already had an Aikon AK32Pin and a Matek F411 Mini SE sitting on my shelf. The vertical staggering was symmetric about the side arms, which means the 4 cross braces are identical. I also canted the side arms at an angle to leave room for a battery strap, and added a couple of 3D printed bits to cover the sharp carbon edge and prevent straps from getting cut.

Designing the canopy on the other hand was a huge pain. It's been a while since I've done one, so it took a couple of hours to figure out surfacing in Solidworks again, and then once I started the file got messy real quick. It ended up taking best part of 3 days of on/off work and several restarts to end up with what you see here - still not 100% happy with it, but it'll do for testing for now.

When it came to component choice, obviously the stack was decided by virtue of already having it, and for motors I decided to pick up a set of AMAXinno's new range. I've always had a great experience with their motors, and figured for a lighter (by my standards at least) quad I might as well stick with the lightweight theme and use 2305s.

Foxeer Predator Nano came out of a failed toothpick project, and despite not being the smallest or lightest VTX I went with an AKK race since I have a ton of them. I also ended up 3D printing a shelf that the stack bolts screw into to mount the VTX and XM+, to keep things as compact as possible, along with my usual stack spacers and RX antenna mounts which on this build are completely out of harm's way far below the propline. Flywoo LED racewire (in pink!) rounds out the build, and should look pretty wild on the track from behind - hopefully where most pilots will be seeing this quad from!



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apexfpv   May 07, 2020  

Is there a place where I can purchase the frame? It looks spectacular!

CarbonRain   May 07, 2020 

Thanks very much! Still very much preproduction at the moment, wouldn't be happy selling them until I'm sure it won't break as soon as it hits a gate - unfortunately lockdown here in the UK means no flying, but hopefully it won't be too long before we can get back in the air again and I can put some time in with it :)

apexfpv   May 07, 2020 

Let me know once you get something figured out!

Sabredave   May 10, 2020 

I too would be interested. Looks really nice!

Jodie Froster   May 09, 2020  

Beautiful work

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