Inspired by the lightweight (but relatively expensive) fun the Tiny Whoop brings, this is a minimalistic frame replacement for various toy quadrotors that allows for building absolute minimum weight and size versions of them. Compatible quads are for instance the H8Mini or H101. The "frame" consists of 4 clips that are used for mounting motors directly to the flight controller PCB.

For use, disassemble the quad, print the four parts and glue them to the frame with a dip of hot glue. If you parallelize printing and quad dissassembly, you'll have a superlight quad within approx. 20 minutes ;)

See also these two blog entries for some more information: https://skmavs.wordpress.com/2016/08/25/a-superlight-3d-printable-frame-replacement-for-toy-quads/
https://skmavs.wordpress.com/2016/09/11/super-lightweight-fpv-quads-using-customizable-motor-mounts/

The frame has been created using OpenSCAD and is fully customizable. It gracefully deals with changes in dimensions and the motor diameters, lengths etc. can be modified using either the Thingiverse customizer or by opening using OpenSCAD and generating a stl file.

The model source is also hosted on github for version control and possible collaboration/forking: https://github.com/skohlbr/openscad_models/tree/master/mini_quad_motor_mount

Update August 26 2016

The sides of the model have been strengthened a bit, so it is more robust against breaking. The changes can be inspected using the diff tool on github.

Update September 11 2016

The mount has been improved significantly. It is now much more robust against breaking and the OpenSCAD model has been modified to allow specifying the desired propeller diameter and prop to prop distance. The size of the motor mount is then computed automatically. The changes relative to the original upload can again be viewed on github.
See also this posting going into some details about the changes: https://skmavs.wordpress.com/2016/09/11/super-lightweight-fpv-quads-using-customizable-motor-mounts/