For this lego set, I've used a existing block product that isn't a lego product that is modified and has rocket launchers and is remote Controled. The gear mechanism us simple, the gears move when you press a button of the remote. The remote has battery's and the actual robot has to be charged by a charger and it doesn't take long for it to charge. I think this would be a good lego set because kids could play with the lego and at the same time, they could control it with a controller. PLEASE support this lego, it would really help me.