RE: Metal reinforcements
If you go metal, highly recomend adding a larger heat sink to the board if not a computer fan Processor type. Another Highly recomend is go on the fact section of this Tank Forum and scroll down until you see breaking in the motors and breaking in the the gears! For the gears I just used a diferant motor instead of the guys idea to use the power drill but you could use that and I ran them all night covered in gritty hand wash, washed them off with chainsaw grease and ran them all day at work after cleaning them with WD- 40 and another lubricant simular to liquid wrench! Right now the metal gears with out the motor roll like the plastic one and to me that is the goal other wise you have drag and with the extra weight, you just going to get bogged down in the dirt and smoke a board. Oh and break in the motors it fast an easy. I removed them from the Gear Box taped two D -cell batteries together and let them run for about 4 hours, check out the fact site they have photos and other batteries and gritty material you can use! It sound like a lot of work but it was a blast and now ! have some gears that hum! And it is a good time to check the clearance on the gears I had one main gear that need a little spacer so it wouldn't chuck back an forth and tighten the screws would not do it these are cheap and obvioulsly the factory inspectors don't care or can't tell if the axle is 1 or 2 mills differant but you gear box can suffer for it!
The Blitz