I was inspired by my make of https://www.printables.com/model/120102 . But I wanted something bigger. Therefore, I created my own, bigger model. Clearance for the wheel 0,4mm to each side. Lube the axis a little bit with some kitchen oil to let the toy roll better.
The model will need a little bit of support. Be careful, so you don't trap the wheel in supports. See 3mf file or print pictures.
Length: ~13cm
Widht: ~6cm
Height: ~6cm
The author hasn't provided the model origin yet.