Hi! i got 2 small/big problems with the RepRapPro Huxley,first, the big, how far up is the heated bed supposed to go? its bumping into the motor as it is right now, second, the small issue is that (and btw i have fully wired it) I got the 2 fan wires, (one cut off) i got – and + wire but i was so stupid that i marked it with some color that now has fallen off, so i dont know which wire is + and -, is there some way to test this? thanks!