Having received the TECHNIC 4x4 Off-Roader as a gift, young humanoid
wanted to motorize it with the NXT. However, the exiting drive train
proved too weak to move it around. So young humanoid constructed a
custom chassis. One NXT motor drove the machine for four wheel drive,
the second provided four-wheel steering and the third shifted gears in a
two-gear transmission. Young humanoid then compacted the 4X4
Off-Roader's bodywork and put it on top. Unfortunately, the gears were
prone to slipping and the single motor did not provide enough power.
Strangely, moving the machine forward resulted in more stress -
eventually to the point of slippage - on the drive motor, but when it
was reversed, the stress would be relieved. Young humanoid is still
mystified as to why.
