Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:5854542.

This my version of optimus prime's iconic truck and trailer which both are print in place without supports with moving wheels. Your printer will need to be decently calibrated to print the wheels, but its not a super tight tolerance so most should be fine. The pin is used to connect the trailer to the hole in the truck bed, alternatively you could use a wooden dowel of the same size. The truck and trailer should lay flat on their side.

Make sure to post a make and check out my other models.