To be able to control the laser dot I need to create a drive mechanic that would fit the lamp hole of a earth globe. My 300mm earth globe have a 38mm hole in the bottom that everything need to fit through.
I started with making a CAD model of what space I had and begun to design the bottom mount that will hold everything inside the globe and also pass the power to electronics.
This is what I come up with, an aluminium part that replaces the lamp mount and have DC-input in the bottom. The centrepin of the DC-input is coupled to the output of the 1000:1 reduced motor, which causes the motor housing to become DC positive. DC negative is passed through the bearings that makes the mechanics to freely rotate without any limitations.