In this part of the ZMR250 low cost mini quadcopter racing drone build we add the arms to the main frame and do most of the wiring. Two options are demonstrated -- simply joining the wires directly and using a very simple and cheap home-made power distribution board. Remember, while stocks last, viewers can request a free el-cheapo PDB by sending me an email with their name and address. I only have enough PCB for about 10-20 boards so it's first-come, first served. Stay tuned for part 4 when we'll install the Naze32 board and the FPV camera/transmitter then set things up.