ok since my current airsoft aeg is an M4 model produced my ICS,  I will start by making 3d printable M4 mags,  over time (if this project succeeds) I will work on producing 3d printable mags for all of the main popular airsoft aegs including, AK, steyr, P90, g36, MP5 to name a few .  

  ok so to keep the 3d print as cheap as possible I need to keep the number of parts  to print as low as possible.  So far the casing will require 2 parts to print, ie the 2 sides,  the bb feeder will also need to be 3d printer. I was unable to locate easily the springs normally used in these magazines so I am looking into using easily obtained elastic bands to push the feeder and feed bbs into the aeg.  lastly the tiny nib that stops bbs flying out of the magazine when not in the aeg.  

  I will start by mocking up ideas in sketchup first, it will be a few months yet until I get access to a 3d printer in order to be able to test ideas.