Mom with questions

Hi all,

I’m a mom looking for advice. (This is not really my area of expertise 🙂.) My 8 y.o. son wants to get into building RC construction equipment. He definitely has an aptitude for this kind of thing but I have NO idea of where to start. He is frustrated with his toy-grade equipment because he can’t do real work with it, and I think this would be a great project for him. Are there kits one can buy in the US? Plans? He would like to build an excavator. Where do I start?