Update on 04.15.21: Added a new version of the coupling with a removable link element. The link is designed to allow the buffers of the locomotive and the car to be clear of each other, what means that given the smallest radius of turns (500 mm) it needs to be fairly long, leaving a considerable gap between the buffers when going straight. But I guess most model railways have this in common. Possibly, in the future, I will update this with a better solution.

I also added the non-functional versions of the coupling and of the hose connectors (falsely named cable connectors in the previous version), from the non-motorized version of the locomotive, for those who prefer a realistic-looking car but with no coupling capability. I removed the lose connector parts as they were simply too tiny and there was no way to actually connect them to the connectors, so I have given up on connectable hoses altogether, for now.

Update on 04.14.21: I have added some photos of the first print, and also a new part, the "Chassis Support", which is a triangle for lateral support of the wheel hub-spring assemblies, to ensure these are perpendicular to the frame and don't break off so easily. I updated the Assembly Reference m3f file accordingly so you can see where these go.

Update on 04.03.21: When printing, I noticed that there is an invisible gap under half of the Long Side of the car, causing misprints. So I extruded the whole thing down, replaced the file with the updated one ("Ext" at the end) and it should work fine now. The short side printed with no Issues.

The coal car is the first of the 35mm-gauge train system trains, intended to be connected to the YT01 locomotive, which is soon to be motorized (I have a working prototype of the chassis, but I am still printing and trimming the exterior parts to fit the new mechanisms).

The coupling is missing (or rather there is a non-working version of it included). I am currently developing a new mechanism for this, which I will be adding soon.

When building the model, take care to make the distance of the wheels on the axle smaller than the maximum the track will allow, or otherwise the car will derail in the 500-radius turns. The easiest way to do that is simply to not glue the wheels to the axles at all. Bring them as close to each other as possible, testing them on a track, so that you can still safely avoid slipping of the wheels from the rail onto the inner side of the track, i.e. sleepers. It's fairly easy once you get the hang of it.

I could have prevented these issues altogether, had I made the wheels slightly wider and the rim more sloped, but I wanted to keep realistic proportions, which of course normally would only ever be used on tracks with much higher turn radiuses. But shortening the distance between the wheel works reliably, if done with precision.

This time, I took more care designing the parts with printing in mind, but some parts will still require supports, in particular the hub with the spring and the coupling, but to be on the safe side, please allow heated-plate-touching supports for all parts, as some of the flat parts may have small depressions in them.

The longest part is 240mm long

There are 28 individual parts in total. Some need to be printed multiple times. To see how they all fit together, take a look at the 3mf assembly file (MS 3D Builder), or at least the merged STL reference model.

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