We have developed a model made with our Totem mechanics, as an example of what can be built. This model could be as a fun home accessory or even a step in learning robotics coding.  The main idea is to make a steel ball (bearing balls, in fact) position itself by position detection. With the help of two standard servo motors (180 degrees) it makes the ball roll in either direction. And it can make it stop. It all sounds easy but it involves some clever coding. So if you push the ball with your finger, it immediately starts trying to get the ball “home”.

The video will show it in operation.


We have showed the model in different exhibitions we have attended, and people were curious to know how to make it. Therefore we have made building instructions. The video shows us building it, also the instruction book will show you  how to build the Roller Bar step-by-step.

However, not all parts are available from our web-shop at the moment. Most will be available later, but for now you would have to provide yourself with some parts if you want to build this model. Also you need to either make the plastic coupling to the servo motor by cut and drill, or 3D-print it. An STL file is available HERE.

Resistive strip and a copper tape are also not Totem standard parts. They are used here to detect the position of the steel ball, it will measure the direction and speed of the ball. See the instruction book for more info about how to purchase the missing things.


>>> Roller Bar Instruction book <<<


It is a fun way to learn robotics coding as it involves finding the speed, acceleration and position of the ball. Besides learning how much each Servo motor must be dynamically activated.

Try making a “living ball” of your coding. Make it interactive!


Totem Team