@scabaa Hiya ^-^
Yep that one's me. I printed mine out of PLA+ with 6 walls on a 0.4mm nozzle. Layer height was less than 0.2mm and was surprisingly strong so anything you do beyond that should be more than good enough to hold it in place :)
For funwheels they're pretty good out of the box but for piece of mine I'd recommend a line of silicone around the boxes just to be safe.