This is a model of a Chaldron Wagon, designed more to the scale of the wheel sets you can buy from Hornby, than off the real thing. The wheels of the real one's are much smaller, in scale, which is why the sides are not quite at the correct angle.

I've included both a static version that has printable wheels and no NEM socket as well as one that you can actually run on your railway; if you add a tube to act as a bearing, insert some wheels+axles and a coupling into the NEM sockets.

I used Hornby "R8100 Split Spoked wheels" as they were the closest looking to the original wheels.

For couplings I had originally used Hornby "R8219 NEM Couplings", but shortly after I designed these Accurascale came out with their ready to run Chaldrons, but also came out with a chainlink magnetic coupler, that has a NEM plug. Which is almost perfect. You just need to shorten the chains a bit, as they are slightly too long.

There is no bottom to the wagons, as I put a thin piece of plastic card near the top and added some Iron Ore ballast (as I am using them in an Iron Stone mine layout). They were originally used for coal, so you could put some simulated coal in them instead.

The model was designed for resin 3d printing, not filament.