I like to scale up these designs and print them as large as I can but keep settings around .15mm layer height and 15% infill. For the Wheel Loader, I was able to bump it up to 225% making it more than a foot long. For fun, I printed the bucket in a hard Galaxy Black ASA filament. The tires are in a Shiny Black TPU to give them a little flex and the rest is in PLA. Looks great by my desk.
Wow I can see you have put in a lot of research into upscaling this print. I really like how you used the shiny black TPU to make the tires a more realistic, it is a great detail. The wheel loader looks even better at this scale. Thank you for sharing your fantastic print with the community, we will give you 1 point to your account. This print is exceptional and we hope to see more posts from you in the future!