Documenting my trains project

[McWaffel]

Hey guys!

As some of you know, I recently got back to Lego trains after 15 years of neglect. A close friend of mine thought it was a good idea to document my progress, thoughts and plans on a personal blog, so others would be able to one day build their own big layouts and see what I struggled with and how they can do it better. I'd like you guys to check it out and use this forum to comment on my posts and maybe give me suggestions (I love ideas) on things you would want to hear about or see of. This blog is entirely dedicated to my Lego trains project. So far there are 4 blog entries (The latest one is being uploaded right this moment). If you wish to comment on something, let me know which post you're referring to, so I know what the topic is. 

http://wafa-sadri.de/pages/blog.html

Thanks for checking it out!

//Edit: By the way, I try to post once a week, every Monday.

Edited January 3, 2017 by McWaffel
Forgot to add some info

[McWaffel]

Heyho friends, 

I just uploaded a new blog post. There's a couple of pics and a video of my progress there to be checked out by you! Looking forward to any feedback :) 

[dr_spock]

I have a suggestion.  If you can make your photos a bit bigger or make them hyperlinks to a bigger picture, that would be helpful to see the details. 

 

[McWaffel]

52 minutes ago, dr_spock said:

I have a suggestion.  If you can make your photos a bit bigger or make them hyperlinks to a bigger picture, that would be helpful to see the details. 

 

Thanks for the feedback. Yes this feature has been requested many times by some friends and I will work on that this weekend :)

Edited January 9, 2017 by McWaffel

[FreeBee]

Nice to see the birth of your layout.

Here are some ideas which could be helpfull:

- Give the trains different priority levels: this will solve two trains occupiing the same block (s).

- U could randomize the priority.

Good luck and have fun.

 

Edited January 10, 2017 by FreeBee

[McWaffel]

6 hours ago, FreeBee said:

Nice to see the birth of your layout.

Here are some ideas which could be helpfull:

- Give the trains different priority levels: this will solve two trains occupiing the same block (s).

- U could randomize the priority.

Good luck and have fun.

 

Thanks for the feedback. Priority seems interesting. Just so I understand correctly, you mean something like giving passenger trains priority over freight trains so they can "overtake" a freight train at the next possible opportunity? I think that would look really cool if two trains are following each other and one overtakes the other at the next two track rail road. Thanks for the idea :) 

[McWaffel]

I just uploaded a new post and updated the site, so @dr_spock can now look at the pictures properly 

[dr_spock]

Yay, I can see. Thank you.  

 

[McWaffel]

Hey Guys!

I've been very busy in the last weeks. I went shopping for hardware on Wednesday and I just had to put it together today. I got really inspired. I think I should buy hardware more often :D keeps the motivation up. Anyhow. I've built a first prototypical signal box. And before you say anything, yes I know, I could have run just one ground wire. That's the plan for the whole layout, where I will run a single, long ground wire through the whole layout and will solder any other connections to that ground cable that's running along. Here's some pictures - as always feedback is helpful! 

Soldering is much easier when the Lego bricks hold the LEDs in place.

Using technic bricks to run the wires through the base. I'm really pleased with the result.

Because there's three holes, I can use that to separate the wires for easier access at every signal.

Red signal on

And the green signal of course. I'm not too happy with the color of the green LED... it's too yellowish for my taste. I'm going to replace that one. But I'm extremely pleased with the rest! 

@Lowa you might wanna give this a look. Although I liked your signals, you may want to sell a small signal box with free-hanging LEDs that people can put into technic bricks like I did. Just and idea for you to think about :) 

Edited February 10, 2017 by McWaffel

[ColletArrow]

Pretty good! I've experimented with similar things on a more temporary basis, and found a good plan is to flatten out the wires and feed them under the base plates - that way they're out of the way visually. However, this limits lights to be positioned at plate joins, and makes access harder. My 'layout' is only 96x80 studs, so I only had one signal and no problem...
How are you controlling these? Computer or manual switches? I think the latter would feel more involved, but that's my opinion.
And many 'green' LEDs will have a yellowish colour.

[McWaffel]

My full layout, as planned, is about 3x2 meters in size. It's pretty big. There will be about 8 blocks (train signaling blocks) which means about 16 main signals, 4 station signals and 8 switch signals. That's 28 signals in total. They're all computer controlled though an Arduino for which I'm writing a rather large and complicated program in C++. Main signals are bi-directional and blocks need to be reserved by trains to get them to signal green. A reservation can be revoked for a train if another train with higher priority is approaching the block. It's extremely complicated  gives me nightmares.
I have to admit, that I actually like the cables to be visible next to the track. As long as I can keep them tidy running along the track I'm definitely keeping those there. 

[Tcm0]

It's not uncommon to see cables running along the track (mainly for switching tracks and level crossings). I think that they should stay visible, too. Maybe they can be hidden in a light gray box or something.

[Redimus]

32 minutes ago, Tcm0 said:

It's not uncommon to see cables running along the track (mainly for switching tracks and level crossings). I think that they should stay visible, too. Maybe they can be hidden in a light gray box or something.

In the UK, they tend to be under cover, so whilst there is something to see, it'd be heard to get a reasonable representation in Lego scale and actually have it cover the wires. Perhaps another solution would be to build a slightly raised trackbed, so the wires can disappear under the ground level. 

You could have them above ground level representing telegraph lines though.

[Tcm0]

50 minutes ago, Redimus said:

In the UK, they tend to be under cover, so whilst there is something to see, it'd be heard to get a reasonable representation in Lego scale and actually have it cover the wires. Perhaps another solution would be to build a slightly raised trackbed, so the wires can disappear under the ground level. 

You could have them above ground level representing telegraph lines though.

They tend to be under covers in germany as well but I've seen serveral cables running along the track (I don't know much about the real train tech but I suppose that it's a savety measure against flooding). I think that I found a picture of them (and I searched half an hour) but it's not very good. Look at the straight lines directly near the left track.

Edited February 11, 2017 by Tcm0

[McWaffel]

18 hours ago, Redimus said:

Perhaps another solution would be to build a slightly raised trackbed, so the wires can disappear under the ground level. 

Whilst I did think about doing that, I just don't have the funds available to do that. Do this probably won't happen. Although this would probably be my most preferred solution.
 

18 hours ago, Redimus said:

You could have them above ground level representing telegraph lines though.

While this is also a nice idea, there would be a lot of cables running towards the end. About 30 cables in a bunch. That's probably too much for telegraph lines.
Here in Germany the cables are in a sort of cable shaft that runs alongside the rails. Either way, for now I'll have them running at the side, held in place with bricks and at the end I'll probably build a little Lego housing for the Arduino where all the cables go into. That would be fun I think. 

[McWaffel]

I've been busy today, rethinking my signal design a bit. Here's where I ended up:

 

This is the most obvious change I made: I added an additional red LED to the signal. This shows if the system has encountered a failure and the whole thing is going into a security shutdown. All trains will have to perform an emergency-stop if they encounter a signal like this.

This is the new signal for a regular halt. I'm using the outer LED for a simple reason: It's further away from the "inside" and so it's less likely blocked from view.

And of course the green signal, nothing has changed here.

 

And finally this is where my Arduino is now, I'm using technic bricks to sort cables a bit. The last picture isn't up to date because I now only have one ground cable where all the LEDs ground themselves on. So the total amount of cables is still only 4, although I added another LED to the signal. Also I added a small resistor to the circuit to reduce the heat that the LEDs produced due to the high current that was flowing (my bad). The housing has a removable lid.

[McWaffel]

Well, I've been busy connecting all the sensors and soldering a power distribution board for the sensors and connecting them all up. The cable issue is really getting out of hand! 

Here you can see a Minifig worker installing one of the main signals onto the track :D

As you can see, there's a lot of cables going everywhere. I'm running all cables along side the track for now, but they will end up beneath the table on my full layout once I got all the technical stuff sorted out.

Here you can see the heart of the system, where everything comes together. The distributer board will end up inside the box at some point. It's much easier for maintenance this way. The yellow cables connect the sensors with the distribution board, red cables deliver power to the distribution board and the main signals, black cables ground the signals and green cables are for measuring the drop-out voltage of the sensors.

[ColletArrow]

Looks fun.  At least you have a colour code system. Have you put number tags on each cable so that you can find each end later? Otherwise you'll have fun troubleshooting if a cable becomes disconnected! I can't wait until this is up and running!

[Phoxtane]

Cable management will be of great importance for this setup. I can't recommend anything specifically, but McMaster-Carr has a wide selection of sleeving for you to choose from. Personally, I'd probably go with some abrasion-resistant (braided) stuff since you're presumably going to moving stuff around until you get everything just right. https://www.mcmaster.com/#standard-cable-sleeving/=16hwme3

Also, keep in mind that the Arduino used here can only handle 200mA maximum being drawn or sunk on the digital IO pins. I found this information here: https://forum.arduino.cc/index.php?topic=121675.0 . If you're driving more than a few of those signals at any given time you'll need to give them their own power supply so you don't cause damage to the controller. Looks good otherwise!

[Tcm0]

25 minutes ago, Phoxtane said:

Also, keep in mind that the Arduino used here can only handle 200mA maximum being drawn or sunk on the digital IO pins. I found this information here: https://forum.arduino.cc/index.php?topic=121675.0 . If you're driving more than a few of those signals at any given time you'll need to give them their own power supply so you don't cause damage to the controller. Looks good otherwise!

It's probably sufficient to use the 5V output as the new power supply. The max output values normally only apply for the input/output pins.

[McWaffel]

4 hours ago, ColletArrow said:

Looks fun.  At least you have a colour code system. Have you put number tags on each cable so that you can find each end later? Otherwise you'll have fun troubleshooting if a cable becomes disconnected! I can't wait until this is up and running!

I don't have tags on them yet but I think I should definitely do that relatively soon. At least, once I'm going for the bigger layout that's definitely a must! Thanks for the tip. I'm going to have one train running fairly soon. I'm planning on getting multiple trains moving through the layout by the end of march. We'll see how it goes :D 

4 hours ago, Phoxtane said:

Cable management will be of great importance for this setup. [...] I'd probably go with some abrasion-resistant (braided) stuff since you're presumably going to moving stuff around until you get everything just right. [...]

Also, keep in mind that the Arduino used here can only handle 200mA maximum being drawn or sunk on the digital IO pins. [...] If you're driving more than a few of those signals at any given time you'll need to give them their own power supply so you don't cause damage to the controller. Looks good otherwise!

Yes, I think I'm going to write down a concept for cable management and make a data sheet where I create some sort of code and/or convention what cables do what and how they have to be labeled, so that I can identify them much easier later on. Also I know about the Arduino limitations. Ultimately I'm going to use transistors to control power supply to the signals through the Arduino from an external power supply. So I'll use the Arduino just for controls. I'm planning on about 10 blocks, which would require 25-30 main signals (depending on the amount of switches I'm going to put in) and anything from 10 to 15 secondary signals. Also I'm going to use switch motors and all sorts of sensors. I'm easily going to exceed the limitations of the board. But for this small-scale table-top-test layout I'll just stick with this for now, as that's just easier to change and debug.