UPDATE - There is a new version for 3.5" propellers: http://www.thingiverse.com/thing:1274656

UPDATE - There is a new V2 version with many improvements, especially:

• heavily reinforced arms and base
• square design (motors on roll & pitch axis are equidistant), MTM is therefore 155
• LED plates between arms in front and rear part (30x7 mm, e.g Diatone led for ZMR250 will fit this space)
• thicker spacers

Red Dwarf is a micro/mini 135/155 size FPV indoor/outdoor racing quad which is easy to print & build and very funny to fly due to its size and agileness. You can squeeze it through every hole :) It is designed to be one of the smallest and lightest frames that accommodate 3" propellers and standard size components like 1306 motors or CC3D atom flight controller board.

Here is a sample video from one of my flights to show that it really flies very good: https://youtu.be/3uZTKIl4EOc. It's capable to carry HD camera for recording like Mobius or even Gopro/SJCam. Video from this maiden flight is raw FPV video captured in my Skyzone 3D Goggles. We also tried some indoor racing: https://www.youtube.com/watch?v=Qn6DaZgi6AA.

When printed in ABS with 100% infill it's also rigid and will survive many crashes.

Total frame weight is about 32 grams (ABS, 100% infill, M2 self-tapping screws), AUW with FPV gear and 3s lipo 500 mAh is about 200 grams.

My recommended setup:
motors: 4x 1306 3100kv (http://www.banggood.com/DYS-1306-3100KV-BX-Series-Brushless-Motor-For-Multicopter-CW-CCW-p-962149.html)
ESCs: 4x DYS SN16A (or similar size and amps) (http://www.banggood.com/ZTW-Spider-Series-18A-OPTO-ESC-With-SimonK-Oneshot-Program-p-983660.html)
flight controller: CC3D Atom (http://www.banggood.com/OpenPilot-CC3D-Atom-Mini-CC3D-FPV-Flight-Controller-CC3D-EVO-p-970762.html)
propeller: 3045 bullnose (buy 4045 and cut it to 3") (http://www.banggood.com/2-Pairs-Gemfan-4045-ABS-CWCCW-Propeller-For-Mini-Quadcopter-Multirotor-p-975231.html or http://www.banggood.com/Gemfan-3030-ABS-Propeller-Prop-2CW2CCW-4-PCs-For-RC-Quadcopter-p-1005548.html)
battery: 3S LiPo 500-900 mAh (http://hobbyking.com/hobbyking/store/__25505__ZIPPY_Compact_500mAh_3S_35C_Lipo_Pack.html)
FPV camera: mini PZ0420 (or Eachine700tvl) (http://www.banggood.com/Eachine-700TVL-2_6mm-Lens-1-3-CMOS-110-Degree-FPV-Mini-Camera-p-991027.html)
video TX: FT951 25mW (http://www.banggood.com/Eachine-ET25-5_8G-32CH-25mW-7-24V-Super-Light-Transmitter-p-991026.html, http://www.banggood.com/5_8G-Circular-Polarized-LHCP-Antenna-Short-SMA-RP-SMA-p-965219.html)

This 3S setup has very high power to weight ratio and flies really well.

Software:
BLHeli14.1 firmware for ESCs + Damped Light mode + Oneshot125
Cleanflight 1.10 Luxfloat controller PIDs:
roll/pitch: 2, 0.040, 30
yaw: 6, 0.040, 5
looptime: 1600

There is also a bigger version for 4" propellers (http://www.thingiverse.com/thing:1003801) and 5" propellers (http://www.thingiverse.com/thing:1069161).

Have fun!