1/14, 1/16 or other scale? Where to get started?

[jevs]

I am looking into a kit or a conversion project to do with my son and also serve as a Christmas present.

We were watching some RC Construction Site videos on Thanksgiving and thought that building something in that realm would be fun.

I have been doing RC all my life off and on between other hobbies (planes, cars, heli, multirotor, etc). I also build real cars, bikes, trucks, have designed CNC machines, etc. but never got much into scale land RC vehicles for some reason. I always wanted faster RC cars, but I guess I am getting older now so more functions and scale moves are becoming more interesting to me.

I don't really have a lot of interest in doing the racing buggies, truggies etc. or anything like that anymore. I always get bored real quick after I finished building them. There really isn't anything new to do there. Until my son gets better at flying, I think we need to do something land based. My son would be fine with building a 1/10th buggy or something, but I want it to be fun for both of us, so this is a better option and it doesn't just feel like work for me.

This construction type stuff looks like it would be fun for us to do. I have been wanting to do an RC kit of some sort with him for awhile and now he can finally turn screwdrivers properly. I think it is time.

Anyway, I have been looking around for the last couple days and cannot decide what scale to go for or what to get. It seems like 1/16 and 1/14 are the most common?

There seems to be no heavy equipment kits of any kind unless you want to spend thousands. I don't want to do that. I don't mind spending some money, but multi thousand dollar kits are out of the question.

So, any recommendations on something to start off with? A kit would be nice and easy, but they seem to mostly be 1/14 and just semi type trucks. A lot of the conversions and stuff seem to be 1/16" (Bruder?). I am not sure how well these scales go together when the models are interacting.

I am fine with doing one of the less expensive Tamiya semi's or something if that's the best option, but then it still comes down to scale matching to future vehicles.

I would like to have a couple vehicles that can interact so we could both operate one eventually.

As far as my capability, I can fabricate most anything, design, machine, 3D print etc. My day job degree is in electronics, so anything related to that is not a problem either.
I do have a 16x40 lathe, CNC machining center, 3D printer, various welders, etc. etc. So I can fab when needed, I just want him to have stuff to do also without getting bored watching me.

However, with that said, if there is not some "just bolting it together", then I am afraid my son might not be as involved.

I know this is a long read, but I figured it would save some questions to better explain my experience level and what I was hoping to accomplish.

I would love it if there was a few hundred dollar excavator, high lift, or other dirt mover kit, but that just doesn't seem to be the case from what I can find so far.

Just looking for some ideas/advice.
Thanks