Ball Mechanics
|Star Wars EP7 BB-8 Droid VERSION 3
This page is about the main ball assembly, check out the main project index for the rest.
There are some YouTube videos about this section
The main ball is similar to Version 2, but printed in twenty sections, it is also 300mm wide. This is called the ‘cheese’:
Inside the cheese is a single-axis ‘banana’ piece which is driven along by a wiper motor. The guide wheels have 3D printed Ninjaflex tyres and bearings in their centre:
Hanging on the banana is an axle which allows the Droid to shift weight side-to-side for steering and stability. This is called the ‘trousers’. There will be pockets in the trousers to hold the batteries:
The trousers are driven by another wiper motor at half the radius of the cheese, and with a drive wheel half the radius, so the overall speed in both axis is the same. Hung on the trousers is a reaction wheel full of lead shot which allows the Droid to spin on the spot:
Here it is all mounted together: