I want to build scale models o

I want to build scale models of top tanks along with my son. To have a wide range of top features and functionalities including not just driving motions but weapons that can be fired etc. using some great power trains available nowadays in the RC car industry along with 3D printing for body parts etc. I think this will be a great way for my son to not only to learn about robotics but electronics, software and programming, 3D drawing, electrical principles and also to work with his hands. He has to put in the work and will see end product and achievements whilst learning rather than continuously do gaming for his satisfaction and scores for his results. He has an interest in weapons and weoponalogy but currently simply satisfies his interest by non stop gaming and it has the affect of 'addiction' almost. Thanks.