Brute is 100% Lego, has a pnuematic lift on the front, and uses antenna feelers to detect opponents. I'm not sure how well it will do against other "Lightweight Sumos" because I haven't come across any others yet.

This is a view of the chassis from the back. You can see the motors in the very back (bottom of the picture). Bigger...

This is a view from the top. The motors are on the right hand side. You can see the antenna feelers angling out at the top and bottom of the left hand side of the picture. Bigger...

This is a view from the bottom. My apologies for it being blurry. At the top, you can see two touch switches and the light sensor. Bigger...

It looks like there isn't much holding the motors in, but they are rather secure. The motors have little slots on each side (two are visible on the left edge of the motor) The black beam attaches at the top, and there are little pieces that fit into the slots (behind the 40 tooth gear) and this seems to provide fairly rigid support. Bigger...

Here's a picture of most of the pnuematics. The blue piston is a pump, and it is driven by the motor on the left side. The middle motor has a white clutch gear (slips rather than stalling the motor if it can't rotate) and is used to control the pneumatic switch. There is an 8 tooth gear connected to the same shaft as the gray 24 tooth gear. This drives another 24 tooth gear which is connected to the pneumatic switch. Bigger...

The pneumatic unit from the front (the boring side). You can see the pneumatic switch on the left hand side. The black angled piece provides some reinforcement. Bigger...

Here you can see the lever connected to the pneumatic switch. Bigger...

This is a closeup of the pressure regulator. As the air pressure builds up, the yellow piston will raise. The blue angled pieces connect to a Lego polarity reversal switch. These switches have a dead zone, and when the pressure is high enough, the switch enters the dead zone and the pump motor turns off. When the pressure drops, the red elastics pull the piston down and cause the switch to reactivate the pump motor. This is basically just a copy of Ralph Hempel's design. Bigger...

This is a closeup of the pneumatic switch. You can see the lever, which is connected to the 24 tooth gray gear. Bigger...

Here we can see the pneumatic piston used to lift the fork-lift at the front. This is in the down position. Bigger...

And here it is in the up position. If you look carefully at the previous picture, you will notice a total of 5 sensors. There are three along the bottom (two touch switches and a light sensor). On the left side of the photo, just below the blue tubing and to the right of the white elastic band, you can just make out the yellow portion of another touch switch. This is for the antenna feeler. There is another one in the same place on the right hand side. What! you say the RCX only has 3 inputs! Bigger...

Each antenna feeler goes to a separate RCX input. The light sensor and the two touch switches on the bottom are all connected in parallel. The touch switches are normally open, and the light sensor value is read on the input. If either touch sensor is activated, then the light sensor reads 100%. Bigger...

Here the sensors are all connected together. Bigger...

Here we can see the RCX and pneumatic pump assembly mounted on the chassis. Bigger...

Here we can see the air tank and the 9v battery holder which is used to provide power to the pump. The pump is completely isolated electronically from the RCX, and keeps the air tank pressurized all by itself. Bigger...

Here we can see everything put together. Notice that there is a little gap between the bottom of the fork lift and the touch switches at the bottom. When the lift bumps into something, it signals the program to activate the lift. Encountering the white line at the edge of the ring causes the lift to be lowered. The black pins in the center of the wheels are to keep another robot from hitting the rubber portion of the wheels and making them hard to turn. Bigger...

At start time, the robot has to fit within a 15 cm square. This is what it looks like. It backs up a bit at the beginning, which causes the antenna feelers to pop out. Lowering the piston causes the forks to fall down. Bigger...

Here's a side view with the lift in the lowered position. Bigger...

And one with the lift in the raised position. Bigger...

A better picture of the battery box. Bigger...

Here, the air tank is fully pressurized, and the cutoff switch has turned the pump off. Bigger...

Here, the air tank has been mostly depleted, and the pump is running. Bigger...