These are some models in HO scale modeled off of track and ore cars by bischoffrob.

Contains:

Ore Car / Minecart (Unchanged, except for scaling)
Flat Car (Modeled using original minecart base)
EIMCO Mucker
Lumber Car
Long Lumber Car
Tank Car
Skip Car

Straight Track (Modeled off original short track)
Curved Track
Switch

The flat car has the base already attached, whereas the ore car has the bucket without the base attached. Wheels print separately. For the mucker, It has a base incorporated in the design, so it just needs the wheels, attached to small mounting points at the bottom. The lumber car uses the same wheels and has a base already mounted like the flat car.

Update 6/13/20
-Added EIMCO Mucker

Update 9/4/20
-Added Lumber Car (This model has been changed as of 11:34 PM EST, 9/4/20, because of a flaw in the design, if you downloaded the file earlier in the day, you might want to re-download)

Update 9/6/20
-Added Long Lumber Car & Tank Car

Update 4/21/21
-Added Skip Car