A group of us indoor FPV race nano QX's weekly. All are showing motor failures after 4-5 hours airtime and spares are either ludicrously priced, or on the slow boat from China.

Based on the frame layout of the FireFlo, I wanted to shave some weight off a mono-deck for nano QX board and camera, paired with low-cost Hubsan 7mm motors & props.

The result is this Gnat QX, with the frame weighing in at a mere 3g. AUW without pack is 24g, 6g heavier than stock. Power is exceptional in comparison to EFlites 6mm motors.

Edit: v1.1 - added a second loom band clip for more secure battery fixture v2 - extended arms slightly (optional change to try and remove a small wobble)

Have found there is a huge variety of Hubsan motors/props all claiming to be genuine. Mine flys well on 7 x 20mm hollow cups with props that came with motors. Friends have had trouble with other props so working on a mini bullnose prop trimmer for adjustment.

Edit2: Added 2 new motor cap designs and a beefed up v3 chassis - the extra weight at the motors, stiffer frame and 300mAh batteries bring the AUW up to 35g, but eliminate the wobble. Try a small piece of foam or thin neoprene between the frame and battery - it stops the battery touching the motor connectors.

Edit3: v4 added with band hooks to hold camera more securely and a small stinger to act as strain relief for the battery wiring.

Edit4: after several requests, added an 8.5 mm motor variant for use with Hubsan parts. These motors will probably destroy a stock Nano QX flight controller.

https://www.youtube.com/watch?v=MvO3es128r4

Edit5: added another version of this frame (Gnat–F3) aimed specifically at the new breed of F3 flight controllers, such as the Kylin from Banggood:

http://www.banggood.com/Eachine-SKYkylin-F3-Brushed-Flight-Control-Board-Built-in-FRSKY-Compatible-8CH-Receiver-p-1100694.html?p=JN120678599082016128