My first useable design, although there are many details that could be added (particularly to the underframe) and I realise I haven't got the proportions quite right.

I wanted to make my own GWR open wagons as I felt I could do it more cheaply than buying RTR stock. Using Dapol wheels bought from Hattons at 85p/axle and 25g (roughly) of PLA at £21.99/kg gives a cost per wagon of under £2.50 - at that price you'll have a fairly limited choice of fairly low-quality models, so why not make your own?

Some filing will be needed as the fit of most parts is designed to be tight. The construction of the model should be obvious once you have it in front of you, though a brief guide is provided on Thingiverse. Watch out as the couplings and brake gear may foul the axles if not placed carefully.

https://www.thingiverse.com/thing:6352317/files