I've never used a pull-back motor in other constructions than cars. But recenly I got the idea to apply it into the throwing balls like a catapult
in my new GBC.

The castle has been conquered but princess managed to escape.

Today I would like to show you a simple lego gadget which make your coffee better. My lego milk frother is very simple. You only need 8293 set and few pieces to build it. Medium motor and gear give about 1200 rpm. This is not much but enough for milk foam. Bon Appetit!

This is very practical device that feeds the aquarium fish, when I wander somewhere with my family. It is controlled by Lego wedo and scratch so computer must be powered all the time.

In the third GBC module balls move on the river waves. As a water we used blue windows and roller door. Waves are created by the conveyor installed under the river.

When I saw with my son World's longest LEGO great ball contraption video, we wanted to build a few our modules.