This is a Hand Pump Car in HO Scale. I'm not a "train guy" I just designed this for the Diorama shown in the pictures for something to do but it should make a good display piece for a HO Scale Train set.
This thing is tiny so it's not the easiest thing to print... I recommend having a highly tuned printer.... everything was printed with a .25 nozzle.
Most parts were painted in Yellow PLA (Silver for the Wheels) the Deck was painted brown to simulate wood and everything distressed with black paint before assembly.
I then used super glue and CA accelerator to glue all of the parts together. You just have to hold the parts in position while gluing and then spray with the accelerator to get an instant bond.
Glue both Pump Arms to the Platform first.
Glue the Gear to one side of the Platform in the space in the middle of the Pump Arms (The gear should sit just below were the Deck will be but stick up just a bit.)
Glue the Deck to the Platform fitting it over the arms.
Glue the Pump Arms Skirt to the Deck also fitting it over the arms.
Glue on the Pump Handle between the Pump Arms.
Glue the Wheels to the Platform (You can use a small paper clip for an axle if you want.
Glue the Brakes to the Platform
The Handles on the Pump Handle are straight extrudes out of a .25 nozzle and cut to size and glued in place. (tweezers help here)
The Platform Requires supports.
Print (2) Pump Arms (4) Wheels (2) Brakes
There are two different wheels Files... One with cutouts and one solid if you have trouble printing the ones with cut outs.