Thank you all for your replays.
I can assure you all that my track experiments are exactly 45.0mm/1.771 inch in between the rails, everywhere.
Max deviation/tolerances: 44.8 to 45,2mm.
The ruler was not flat at the tracks when taking the picture.
I had to do some homework before posting
(vids, docs and specs)
The terrier is indeed a very small and very strong loco.
Still alive and kicking. Wow, i thought it was turn into scrap, like my great grandfathers loco.
Even smaller (and stronger?) than our "Bello" loco.
Bello in full glory:
Bello was not a passenger train when she started her life(iron ore, coal), later on she become one.
I would love to have a terrier in the garden...1:1.
The print is indeed out of scale, it was designed to fit on a smaller printerbed 8x8 inch/20x20cm.
I think i will put in some effort to make her more true to scale.
All very helpful comments.