Have managed to take the old mk 10 basic frame and reworked a more advanced gear box into it. This is now a gear ration of 4:1 instead of the old models 2:1. Hopefully this should provided enough power to drive the fully system with the turret and plat armour attached which is where the mk 10 failed. The system is powered by two L motors from Lego and plugged into two separate receivers allowing for two more inputs from a double controller set up. The whole gear box is tensioned inwards by 5 elastic bands. 3 on the top and 2 on the bottom. This is to help prevent the vibrations from the tracks shaking the gear box apart. This had been a major problem from the mk 2 model onwards. This worked well in the mk 10 and was the first model to have a gear box (all be it under powered) that worked perfectly in the sense that it did not rattle itself to pieces.