Spiked roller

This is an extra flourish added to the tank to improve its visual impact! This does not have a specific mechanical function, but it makes the tank look awesome:

The large, spiked roller on the front of the tank adds to its menacing appearance. Earlier in the chapter, we discussed how the roller is set up with a pulley and a rubber band that are attached to one of the drive motors, which makes the roller spin when the tank drives.

The roller is a custom 3D-printed part. You can download the file for the roller where you downloaded the LDD for the tank earlier:

If you do not have the means necessary to 3D print this component, or you would rather use only true LEGO elements in your project, you can replace the 3D-printed spiked roller with another roller design that uses the large LEGO wheel hubs:

The roller adds an extra dimension to the tank's design and contributes to the overall cool factor. When you design your own smart robots, you should think about extra features to add to your project that may not serve a functional purpose, but rather contribute to the appearance of the robot. These types of additions show that you have gone the extra mile to make your robot more impressive.