[Kage]

My team used 3/8 aluminium wheel axles...needless to say, after some gentle bump testing, they were TOAST
we upgraded to 3/8 Grade A Stainless Steel bolts...and after catching a good half-foot of air off the top of the bump at full speed, they are still straight as an arrow...but all that shock to the robot is making our electronics not like us :|
we broke off a jaguar fan...it kinda just broke loose of its own little housing and started thrashing wildly inside the plastic casing, producing one of the most horrifyingly unique noises ever

we also had to modify our ball "dribbler" because the carpet that we had been teating it on before is different from the "spec" style carpet...
when we ran it on our quarter-sized field carpet today, our dribbler kept sucking the ball under our robot.
we build some "standoffs" with rollerblade wheels on the bottom so when the ball begins to get sucked under, it just rolls on the rollerblade wheels

all in all, everything is going great!
Good luck with finishing up your robot!