I realy like the microcontrollers and want to ask for costum gears / gear boxes in the same manner.

The Idea will be something like the microcontrollers: You will have a separate editor and can choose how big the block and where the inputs / outputs will be. In the other tab you will make the ingedients like in the microcontroller editor. Instead of electronics you will have several different gears to combinate. So you can make gear ratios as you want or an differential gear (#4853)

There are many topics asking for any kind of special gears. With costum gears all players will be able to do it for them self.