Russian 50T Boxcar EPII

thingiverse

Soviet 50T Boxcar Epoch II (referred to as GGru) – Version 2 (25/03/2020) I have been creating a 13.5 metre, 50 tonne SZD boxcar in 1/160th scale as per EpochII. I have used SZD declassified blueprints which were found through Russian websites and a declassified CIA document! I have also used photographs from Russian and German sites to get the feel for the prototype which I have never seen myself! I created the design using Openscad (version post May19) using dimensions from prototype blueprints and have scaled them. The design has three components, body, chassis and roof. There are four Openscad files, one for the body, one for the chassis, one for an axlebox and a common file for constants. I have provided several options in the parameter file which allows selection of truck and coupling. Although I have tried to make the design scale independent, there have had to be compromises to fit the 1/160th scale. I have also attempted to make the design modular so that variants might be easily accommodated. Any redesign should be checked before printing. I use slic3r software to translate the resulting .STL files to GCODE. I use a BQ Hephestos printer fitted with a heated bed and a 0.2mm nozzle. I used PLA filaments for the print, black for the chassis, dark brown for the body and dark grey for the roof. The chassis has been designed to resemble the prototype but compromises have had to be made to create a strong component. I have designed the chassis to use MicroTrains 1011 Archbar trucks as a design close to the prototype period. (later, post-wwII might use bettendorf trucks?). I have created this design to use MicroTrains 1016 medium shank body mount couplers. This does give a moderate space between wagons which will accommodate buffers. It might be possible to use MT1015 short shank body mount couplers if layout radii permits. Mounting the assembled MT1016 couplings into their printed box is a tight fit and may need easing. I have tested this design with MT 1010 Archbar trucks fitted with short shank couplers. Wagons are close coupled but negotiate R3 curves. The central spine portions of the chassis neares the wagon ends have been removed to clear the truck coupler boxes. Some adjustement may be needed to the buffer beam to clear the Micro Trains coupler pin. No allowance for Rapido type couplings has been made for this design which may be a future revision if desired. As implied above, provision has been made for traditional buffers as the SZD was converting from 3-link to SA3 couplers during EPII. Some boxcars retained buffers after conversion to SA3 as can be seen in photos. I have not provided facility for traditional 3-link couplings. The MicroTrains trucks have been re-wheeled to use Intermountain Railway 60052 wheelsets. This may affect the underframe height above rail so a check is needed to ensure coupling box clearance on curves. I have added simulated bodyside planking which may enhance the appearance of the design but may be commented out of the source if desired. The body uses dimensions taken as far as possible from prototype drawings but some assumptions have had to be made owing to some dimension values missing on the GA drawings. The whole design (including trucks and couplings) weighed 10grams in 1/160th scale and will require some weight to be added to ensure good running. I suggest adding 8-10grams for an all up weight of 18-20 grams in 1/160th scale. I consider this design as complete apart from a design of the air-brake control valve. I hope that it will be useful and I welcome improvements.