The aim of this project is to maximize the flight time/ battery life of the very famously fun Hubsan X4 quadcopter. I only used spare parts from the Hubsan H107L model. The weight of this chassis is only 4.18g plus battery clip 0.49g. The whole quadcopter including chassis, clip, LED's, motors, propellers and receiver is only 21g. Excluding battery, that is 25% lighter than the original H107L model which weight 27.8g. Even loaded with a 380mAh battery it´s just 3.5g heavier than H107L without its battery. With battery: 31.35g compared to commercial 38.15g. Continuous flight time with a 380mAh battery was measured to 11.5 minutes. I don´t have a H107L to compare with but it should be a difference. Please let me know it you have one. Due to its low weight it´s also very quick and reactive. A great fun to play with. It´s robust enough to fly with but don't except it to take too serious damage. It´s optimized for weight, not robustness. Maybe if you print it with 100% infill and another material it could take more damage. I include the original Rhino CAD file if anyone wants to modify the construction for improvements. It could easily be converted for the stronger 8mm motors for example. For more details of what parts to buy and how to actually build it, please follow this link: http://www.instructables.com/id/Super-Light-Quadcopter/ The print consists of a body that fit original hubsan parts from h107L, including receiver, 7x20mm motors, 3mm LED´s and battery. The clip will hold the battery and I upgraded it to also fixate the cable. Update 2015-02-16: Adjusted battery cable clip for better fit. http://youtu.be/ML9STN5LbJ8The body is best printed upside down. For more robustness, print it with 100% infill. I used Simplify3D with very good result together with Wanhao Duplicator 4x printer and PLA material. For more detailed settings, please see images from Simplify3D. I recommend using manual support structure according to images. I also include my project files for Simplify3D if you want to use exactly my settings and support structure. Extrusion width: 0.46mm Layer height: 0.1mm Top solid layers: 5 Bottom solid layers: 5 Shells: 1 Infill: 10% with 50% extrusion width @ 75 & -25 degrees Support infill: 30% and offset 0,25mm Temp extruder: 218C Temp bed: 60C The battery clip using same settings except printer width=0.42mm and extrusion multiplier=0.99.