I called this the Hummingbird before the Hummingbird was the Hummingbird.

By The Van on Mar 12, 2018

17  795  4

This build slowly evolved from an Emax Babyhawk into what it is now. With the babyhawk I had unshakable vibrations (heh, get it?). No matter what I did to secure the FC, the ESC inside the little plastic frame.. they just wouldn't go away and they made the quad quite unflyable. It was time for a new frame, and for some reason at the time I thought the babyhawk was a 2" (it's a 2.3"), so I went with a nice 2" frame.

So, it comes in and the camera clearly isn't going to fit. Fortunately I had the old cam from my very first quad (an Eachine Assassin which I'm almost embarrassed to admit), and it fit perfectly though quality was not ideal. I eventually replaced it with the RC nano.

The electronics stack is all mounted by that double-sided tape-foam stuff, and then some electrical tape wrapped around the base plate. This works surprisingly well for these small components (the Femto doesn't have mounting holes). I cut a hole in the tape in order to have access to the USB port.

I flew that around for a good while, but the babyhawk motors are just too heavy and too low kv for good 2" flight characteristics. At least, that's the case on 2S which is all I want to run on this thing.

This is when I really started to think about 2" quads and how to get GOOD flight characteristics out of one. Not insane power, but good for some smooth flight in a smaller area. That, to me, is what makes micros attractive! The plan is simple: Make it light, and go for high kv. This is accomplished for the most part by the motors and battery.

DYS 1102 is exactly what I was looking for. Less torque but a LOT less weight - barely over HALF the weight of the babyhawk motors and nearly twice the kv rating. This was to be paired with the most aggressive 2" prop I could find: the Avan micro. The combo makes for great top end with a relatively slow spin-up, on 2S.

It seems the norm right now is to opt for MORE POWER at almost all cost. That being the case, people are using 400-600mah lipos to supply that power to their hungry little 2" nuggets. Since my goals are different, I've prioritized weight and gone with basically the original babyhawk battery - 300mah 30C 2S weighing in at just over 15g! My next lightest battery, a 400mah 30C 2S is close to 26g and the difference in the air is night and day. See that photo with the scale? That's 73.7g all-up. It's sitting on top of the 300mah pack which is small enough that you can't really see it. That means the battery is about 20% of the AUW and nearly DOUBLING that number doesn't work out great.

I'm biased, sure - but this is by far my favorite 2" quad to fly. It makes quick recovery from all sorts of freestyle maneuvers, it flies smooth, it grips corners like the dickens and although it's not built to be.. it's quite fast!



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Krillfpv   Mar 13, 2018  

Also, based on the FC and ESCs, was it a babyhawk or a gremlin? :)

The Van   Mar 13, 2018 

I believe they use mostly the same components. The avans are great! It's good to see prop companies fleshing out their lineups like they are right now. I already really liked the gemfan hulkies, but the avans win for me hands down. They're better at handling prop wash, they grip reeeeally really well, and they seem to deliver a good bit more thrust at the top end 👍

Krillfpv   Mar 13, 2018  

Good stuff! Nice and clean. How are the avans?

doc   Mar 12, 2018  

I like your theory on the 2" class. 1106 lower and kv is way too much for 2" birds. Light weight, 2s, and 10,000 12,000 kv is the way to go.

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