my problem with this board, is that i rushed into it, without fully thinking things through, and doing my research.. now that i have done some research, snd thought about this board more, i feel more confident that its going to work.. im also going to omit the pads in the top that arent being used (pcbexpress automatically makes pads on the top and bottom of holes). i have been thinking about the 90 degree angles all evening (ive been installing IPTV all evening, and even using staples that hold the wires snug can destroy the signal.. wires need to have a certain radius for each corner, and cant be kinked...) so i angled some traces so they have 45 degree bends now..

i will upload another copy of the board later, to see what people think..

if you look closely to the sprockets, some teeth are actually cut out to make clearance for the bolt heads. imworking on changing that design too. i think im going to use only one chain for drive, and make some kind of wheel to support the otehr side. the chains dont stay on well now, because it was almost impossible to make both sprockets line up perfectly... i also want to say, its driven by 2 windshield wiper motors, with 3 x 8.5A 12V sealed Gell cells. one for each motor, and one for the headlights.. we have lots of old coal mines and caves around, so its meant to be able to explore them...