Copter Folding Arm Bracket (S1000, S900)

these are quite a bit wider than the original aluminum brackets for strength, but they will fit the original folding arm, provided you have a 4mm rod. A little bit of drilling will be required if you want to use these with a 4mm rod. Otherwise, these are set up perfectly for 1/8" or 3.17 rods. The screw holes line up perfectly and you can use the original m3.5 screws, or a bit longer if you choose.

Here's the counterpart http://www.thingiverse.com/thing:1343704