This thing is work in progress.
The goal is to make the ultimate micro quad platform: strong, light, modular, adjustable. And crowd-approved ;)
The following variables are planned:

• motor mount diameter (8.5mm, 7mm, 6mm)
• FC mount (AlienFC, Micro MWC, nQX, Hubsan)
• battery mount
• attachments mounts
  Here is the version log:
  V1:
• 120mm shaft diagonal
• 8.5mm motor mounts
• AlienFC cut-out
• holes for rubber bands (battery holder)
• studs (seat for a LEGO pilot or any other stuff you want to fly around..)
  V2:
  complete redesign. The idea of leave springs for total crashability struck me. First flight and crash tests have been nothing short of amazing. Version 2 is taking over.
  V3: complete redesign.
  Now with fully suspended motor holders.