i can't take a pic... it's hard for me to describe when i can't anything about motors.. belive me, it's not my english! i just can't describe.... When the mat is going to the motor and then back it starts jumping and stuff, moving... then it says k-k-k-r-r-r-r-.. I don't really know what the problem is.. tommorow i guy will look on it. And he also said my sled should have reverse!!

i didn't knew that, he said it could be something with the chain, that it had jumped off... Keep on helping me guys :/