This is a HO scale model of a train bogie series 18-100, widely used in USSR/Russian/CIS freight wagons.

There are 2 variants of the bogie, one is designed to be 3D-printed on an FDM printer and consists of several parts. Second variant is for resin 3D printing, so has more smaller details and is printed as one piece. Both have same dimensions and mounting geometry, both can be printed with or without NEM-362 pocket.

You can download STL files here:

Photos
Renders

Technical details

Relevant dimensions

The height from rail level to the top of bogie is 9.8mm when using 10.7mm wheelsets (36" prototypical), e.g. these from aliexpress. Sockets for wheelsets follow NEM 314 (Carriage Wheelset for Tip Bearings).

This model does not contain wheelsets! I strongly advise using ready-made metal wheelsets for better rolling performance, but if you really want, you can 3D print the wheelsets too, the wheels can be found here, for example.

Center hole is for 2mm self-tapping screw or M2 metal screw, hole can be drilled out for larger screws.

There are 2 versions of the model - with NEM 362 pocket for couplings and without.

The minimum size of features is 0.3mm (in rare cases, 0.2mm) for resin model, 0.45mm for FDM variant.