Thats normal. use some plastic or nylon shims to tighten them up. You will want a little play but not a lot. You don't want to put to many in so it binds up.
Why do you guys use alloy? I thought it broke, bent, and warped really easy... I have used RPM for a while now and have only broken 2 arms on HARD HARD impact. I guess it's just personal preference?