I got them all running on one Pi. I think it's a power issue. I hooked up my two that were on a different PSU to the Pi that had the other three on it and it ran well but when I tried to hook up a 4th Hex miner to my PSU that's when my RPi freaked out.
Right now I have three on one PSU and the other two on another but all are on one RPi. So you can have five Hex miners on one RPi!  Now I just wish I could get all five of them or at lest four them going with just my EVGA PSU.