Soviet Railway Signals by pemberton_a

Last crawled date: 3 years, 3 months ago

Soviet Colour Light Signals (03/01/21 )
Update
Since I first published my signal work, I have made several improvements and made my Openscad code more modular. If you have previously downloaded the code files, I strongly recommend discarding them and using the improved modules. I have also added much sizing choice for other scales though I can only use N scale myself.
A video:- https://youtu.be/iJ00azEF8WM
Introduction
I have been attempting to create SZD Signals in 1/160th scale. I cannot claim they are 100% accurate nor every type included but I present them for any interest or improvement. 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 must stress this is very much a work in progress and I would welcome improvements to the design.
Signal dimensions are taken from the book Model Railway by B.V.Barkovskov et. al. Published - Moscow 1989 - ISBN 5-277-00181-6 p78-79. Additional documents with dimensions were found at the Russian scaletrainsclub.com forum. A very comprehensive site in Russian Language.
Method
I used Openscad to create the design (source code included) and create .STL
I use slic3r software to translate the resulting .STL files to GCODE. I used a BQ Hephestos printer fitted with a heated bed and a 0.2mm nozzle for the original prints. I now use an Original Prusa i3 MK3S+ with a 0.2mm nozzle. I used dark grey PLA filaments for the print. Nozzle and bed temperature are 215 and 70 degrees for the first 3 layers, 190 and 60 for the remainder. I have found that some PLA filaments work better than others at the scale I use.
Signal masts will be brass tube and NOT 3D printed. Tube allows wiring to LEDs For 1/160 scale. I used brass tube mast - Brass Pipe Capillary Copper duct Coppery Tube Φ1.0mm (actually 1.6mm diameter externally) post pole (ebay/wehonest_cn). Most 1mm tube (really 1.5mm O.D.) has a wall thickness that limits the number of wires that can be threaded through the tube. It will be necessary to use larger diameter tubing for larger scales. I have added 3mm and 5mm tubes in the parameters file but I have not tested them.
The length of mast in the print are for ‘ground’ to top of mast and is used for calculating the signal ladder length. You may choose to cut the tubing for an extension into a baseboard, which would add to robustness of signal. I have a ‘printed’ advice value displayed on compilation which you may adjust or ignore.
mast_extension = 12.5; // For information only
The LED housings have been improved as the original design had shortcomings in respect of wiring. Additional wiring channels have been added to allow the LED wires to leave the housing blocks adjacent to the mast. I would have liked to drill small holes in the mast to thread the wiring to be unobtrusive but that is too difficult in Nscale. The LED’s I have used used are prewired 0603 SMD bought through eBay but provision for 0805 SMD LED’s with a domed lens may be used (and may be preferable). Larger LED’s would present problems with prototypical lens spacing. If used for larger scales, it may be possible to adapt wired LED’s. I have created, but not tested, round LED housings for normal 3mm and 5mm LEDs for larger scales. Due to the thinness of some of the LED housings, I recommend painting the completed signal with a good paint to stop light leakage. A brass mast will need painting anyway.
The signal face plates have lens shrouds which are very delicate. I have improved the shroud presentation since the first design. I have also generated the smaller size shroud used on the white auxiliary signals and may be used to emulate the imported American General Signal Co. shroud type used on early (1930’s) signals and then produced in the Soviet Union.
The ladder length is set to match the signal type and mast compiled. The current ladder design is much more robust than before. I have added standoff mounts for glueing to the mast which should provide a 10 degree angle. (I’m not sure that is protypically correct but I would hate to be a signal maintainer climbing the ladder is the cold Russian winter!)
I have added, but again not tested, a module for the DDR EZMG (imported Soviet design) auxilliary white signal as well as the standard mast mounted aux. signal found in Russia and CIS. I have designed one and two speed bar aux. signals for mast attachment. I would have liked to create a dot matrix display as attached to signal masts (6x7) but cannot find a suitably small LED display. (There would also be difficulties combining a dot matrix display with the DCC decoders I use.)
Because the design is much more modular, mixing and matching modules can create The signal types I have created are:-
Single Lamp, Single Head (white LED),
2 Lamp, Single Head,
3 Lamp, Single Head with one speed bar,
2 + 2 Lamp, Double Head,
3+2 Lamp, Double Head with aux. white head and two speed bars.
I know there are many more such as the square spectacle plate, single aspect presignal, blue and lunar white shunt signals at ground level or on posts!