This is my first crack at a 12 pounder. Anyways, the weapon is going to be a cheese wedge. I chose this design for simplicity. The drive motors are 2 HF 9.6 volt drill motors being ran on one 9.6 volt batt. It will be controlled by two RCE220s and a Fortress 2000 Reciever. 1/16" diamond plated aluminum for the base and 1/16" aluminum for the wedge. For the sides and back I will be using 1/16" Steel. Im using 6" hard rubber wheels with great traction. All held together with Nuts,bolts,screws and zipties.
In this picture only one drive motor is mounted and the Reciever is mounted.
In this picture the other motor is mounted and the two RCE220s and RX batt are all mounted.
In this picture all of the main components are mounted except the armour.
The side armour is mounted, The 6" wheels are mounted, and all the wiring is done. ITS ALMOST DONE!
Everything is mounted. However it needs a castor on the back to keep the wedge down. And it still needs a paint job. 
Toothless Goalie won 2nd at robot riots! BOOOOOOOOOOOYA! Here's some battle damage!
In this picture you can see the front right is a little dented. THis was in a "grudge match" at the last second. It was 2 12s vs a 30. I ended up leaving Toothless Goalie in as a dead target. And THIS happened!
In this view you can see the back is dented in a bit. 
I have replaced the 6" wheels with 4" wheels for slower more controlled movement of toothless goalie. I will lower the wedge a bit to make it invertable again. 