This large sci-fi style rover was modeled after a Soyuz capsule. It is quite large. The wheels use skateboard bearings so they move quite freely. Everything fits together with E6000 glue (use clamps). The back part is hinged so stuff can go inside.

Everything can be printed without supports on the cheapest printers available. No special equipment is necessary to print these. In fact, if your printer is sufficiently dialed in, you can probably print the bearings.

I'm not all that confident in my printer to make parts that will handle lateral stress across layer lines, so I decided to make axle plugs that are nice and solid out of epoxy resin. I've included the file that you can use to make a silicone mold and then resin pour six bearings if that's what you want to do too (see pics).

Source file (blender) is included for your convenience, and I hope you have fun customizing this model for your use.