ICE for OS-Railway - fully 3D-printable railway system!

ICE - a model of the "Inter Continental Express" (version 1 for those train interested). Some might wonder why I didn't make a model of the latest version of the ICE, the answer is simple, I don't like the looks of it. :)

The model is a part of my larger project called "OS-Railway" with the aim of creating a completely 3D-printable toy/model railway system were as much as possible is 3D-printable and the rest is relatively easy to get, so no specialized commercial train hardware is needed.

Electronics
This is based on the same system and concept as the Hectorrail 141. Please check that page for the electronics: https://www.thingiverse.com/thing:2575667

Main Controller: NodeMCU (ESP8266 evaluation board, programmed with Arduino IDE).
Motor Controller: Dual TB6612FNG from Sparkfun.

A battery box is included in the design, but you can of course put the batteries inside instead as the box is a bit of extra work. I'm using NiMH cells in the battery pack and intend to make a charging station for the pack. I don't recommend using Lithium cells, because they are very sensitive to over-charging and undervoltage. This design (based on the Hectorrail 141 electronics concept with NodeMCU) doesn't have any low-voltage-cutoff so if you use Lithium cells and leave it on, it will probably be enough with one single time and the cess are damaged. However, there are one availble analog input on the NodeMCU that you can use to measure the battery voltage through a voltage divider and based on that you can either flash the lights or make a battery-low-warning of your own design. Given the fact that the system is based on Wifi and a web server it's perfectly possible to send a battery warning to the browser of the controller device if you are using a browser based unit. If you use my "ATC" handheld controller, you will need to add a poll and display for the battery voltage but that is probably not a huge task.

The bogies are slightly modified versions of my separately published bogie:
https://www.thingiverse.com/thing:2644082
Check that page for more pictures and hardware list.

Layout
There are a couple of combination posibilities, you can either print two locomotive bodies and "cockpits" if you want identical ends to your train set. Also, if you intend to make more than one car, I recommend using two motorized locomotives because if you want it to run as fast as mine, a small 16mm motor with low gear reduction will not be able to cope alone with several cars.

A suitable setup for a single motor is locomotive + middle car + end car with "cockpit".
See picture with STL-map for the end car.

Connetion between cars
This model differs from the rest of the OS-Railway system by utilizing magnets for connection between locomtive and cars. It uses a 5mm diameter round magnet. The thickness isn't really important, it doesn't matter if it sticks out a bit from the holder. Glue it in with a drop of CA-glue.

Printing
The main body parts of the train are drawn to be printed vertically. I recommend playing aroun with different settings in your slicer software and look at the previews to find a way that you are comfortable with. I printed the locomotive body without any sypports, it works even though there are some bridged edges that gets a bit rough, but they are under the roof hatches so they are not visible on the final model.

Note! This is a DIY project so a lot of things are not given by the design, things like where you put the electronics, how you run the cables etc. I include parts called "Light Rack" that are meant to be used as cable holders and LED holders. A suitable setup to light the cars are two 3mm LED's glued in the racks. I used large SMD packages and flat cable, that wors well as well. Just don't make my mistake of using semi-transparent PLA and interior lights, the light will shine through! in that case you need to add a layer of paint in order to prevent light from shining through the car body. I will do this before I put up pictures with the lights on.

Don't hesitate to ask any questions in the comment section! I'll

Other Compatible Things (including track and bridges):
https://www.thingiverse.com/groups/os-railway/things

Change log
2019-01-28 Added files for power source rig

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