Hello Gentlemen and Ladies

[curious aardvark]

pet-g has fabulous layer bonding.
It can be tricky to get the settings right - but once you do layers are not a problem.

The LAST material you want to use is 3d printed abs.
It's sucks in outdoor applications is broken down readily by sunlight and fdm abs is one of the weakest materails you can use.
I have no idea why abnyone still uses it. bog standard pla - fdm printed - is superior in every way.

Pla would actually suit your purposes quite well. Certainly for prototyping purposes
Carbon fibre infused filaments are weaker than those without, slightly stiffer - but the stiffness is offset by increased brittleness.
They eat nozzles and aren't even conductive enough to be of any real use.
It's a gimmick that doesn't deliver on any aspect.

But spend some money and you can start using serious filaments.

ninjatek's Armadillo is probably exactly what you want. It's a rigid polyurethane. Tough as nylon, stiff as pla with more strength than pet-g and excellent layer bonding. Also as easy as pla to print as well as light.
https://ninjatek.com/products/filaments/armadillo/


And children - play nice :-)