[Frank(Aflak)]

Originally Posted by greencactus3

oh they break alright. in middle school, i once tried to beltsand a marble into a shape of a cube. the sander did grind quite a bit of the marble away before the marble literally exploded. yes. it was pretty scary. thankfully no teachers were watching. no harm done, but i learned my lesson. still don't know exactly WHY it exploded, but it did.
that doesn't prove if marbles will break on impact but if i were the judges, i might say that it is a hazard in the field because IF it breaks, it can be sharp.
i'd check with FIRST if i were you.
i'm also looking for a way to help us turn easier. i'm not sure zip ties are the best way either. if anyone thinks up an idea, please contact us or post it somewhere.thanks!

ANother idea is to buy flooring epoxy (have you ever seen an epoxy floor -- I have one in my house, its good stuff) and cover the kit pneumatic wheels with it and let them harden. Then you have (basically) wheels with epoxy treads, plenty slick enough for you.