Turbo Thunder Driller (based on Lego Power Miners Set 8960) has 6-wheel-drive and two Power Functions augers!
About this creation
The two Power Miners augers look WICKED and can chew up snowbanks! This powerhouse uses 6 ea. Power Functions (PF) Medium motors, two XL PF motors for the augers, two PF battery boxes, and two PF receivers. Two PF remote controllers operate the "skid steering".
See the Lego Customer Service website http://us.service.lego.com/en-US/BuildingInstructions/default.aspx for the building instructions of the standard 8960 Thunder Driller set, and to see how the unique Power Miner augers are assembled. They have an internal "planetary gear" to make the augers counter-rotate! The wheels and augers share the same pieces -- check out Peeron.com for the full parts list for the Set 8960. I got most of my Thunder Driller parts from www.Bricklink.com.
Note that the PF Medium motors fit nicely inside #40344 Lego Technic bricks (6x8, open center). They are secured to these bricks with #32054 long Technic pins (with stop bushings) that are pushed through the outer holes and into the front of the motors. The rectangular bricks make for a VERY RIGID frame. Axle bushings sandwiched between outboard 1x4 Technic bricks prevent the axles from pulling out during tight turns. This MOC uses both "studless" and "studded" construction.