Published on April 23, 2014
This smart little creature roams the table on a central wheel that is connected to a dc motor. Little plastic arms activate three roller switches on the side as they bump into cups and bowls, causing the robot to turn and try elsewhere. This happens because there is an inverter in between the first dc motor and a second dc motor positioned on the edge.
How To Make It
Let’s assemble the circuit first: power + wire + roller switch + wire + roller switch + wire + roller switch + wire + dc motor + inverter + wire + dc motor.
How it works:
The circuit is pretty simple yet still interesting. Three roller switches are in series and are all set to open mode. This means that the circuit is open (the signal is transmitting) when the roller switches are NOT pressed and the first dc motor will be turning. When one of the roller switched is pressed, the first dc motor will stop turning. However, there is an inverter between the first dc motor and second dc motor. This means that the two motors will behave opposite of one another. To recap, when no roller switch activated (pressed down), the first dc motor is rolling and the second one doesn’t move. When any roller switch is pressed, the first dc motor holds its position and the second dc motor runs.
Note: We wanted our Counter Cruiser to be somewhat small as our table is somewhat small. Our Counter Cruiser measures 6 inches in diameter. We, therefore, had to angle our outer wheel slightly (17 degrees) so that everything fit is a small space. However, if you have a larger table and are not using our template can make the second wheel perpendicular to the first in order to minimize drag when the Counter Cruiser proceeds forward. (We will leave it up to you to figure out why.)