Tankbot

Invading armies usually favour tanks with tracks over wheels. Manoeuvreable in almost all ground conditions, they favour power and reliability over speed and agility. Tankbot is a simple sturdy robot, still standing when the going gets tough. It's a great robot to test out your programming and building skills on and can form the basis of a much more powerful bot later on.

Pictorial instructions for building tankbot appear below - note that the brick and plate colours are shown merely for purposes of clarity. Pay attention to the difference between grey and black pins and bushings however - remember from the kit page that the black pieces provide friction, whilst the grey ones do not.

We're going to add some low-level bracing to Tankbot. When used together with bricks, right-angle plates make it very easy to keep LEGO structures rigid.

The two beams at the front will be used later on to brace the structure more:

Now add the mount plates to hold your motor - you will find these in bag X with the motors.  The picture below should show another thin plate between the mount plates and the red brick.

Two identical plates either side, vertically stacked (shown as black and white) ensure that the motor is at the correct height for mounting.

Find two identical motors in bag X.  Push the motors into the two mount plates, side-by-side in the centre of the robot as shown.

Now add another brick with the motor-mount plates fitted, as shown.  The motors should be secure and level on the frame. 

Start building your gearbox by adding the small eight-tooth wheels to the motor spindle.

Now turn your chassis over - the next step is much easier done from the underside.

Add a 24-tooth gearwheel to engage with the motor spindle gear and another 16-tooth gearwheel which fits the sprocket on the tank tread wheel.

Turning your chassis back around check that both gearboxes spin freely. There should not be much/any difference between the effort required to spin either one by hand.

Now add the tank tread wheel, checking that it engages with the 16-tooth gearwheel you added in the last step.

The front axles are easier - you need to use the bushes to keep the wheels in place, but the 16-tooth wheel can replaced by a bush this time.

Carefully slide on the tank tracks. Turn the wheel whilst gently edging them onto both wheels.

Now add in the handyboard support brick, shown in pink. This will provide a base for our microprocessor board. Make sure once you've done this never to pick up the robot by the handyboard. If you do, the handyboard and robot might separate and the robot will fall away!

Brace the front beams with a 4x12 plate. 

Add bricks to support your handyboard, and Tankbot is ready for action!