JR-Chiisai: Helix

[Martijn Meerts]

As already mentioned in the storage yard thread (http://www.jnsforum.com/community/topic/3241-jr-chiisai-storage-yard-modules/page-8?do=findComment&comment=93733), I've started working on the helix. Of course, I've started on it quite a long time ago, but I finally had some time during the holidays to work on it. I already had most of the wood and track for it, so I only had to order some servos and servo decoders.

 

The helix is a bit of a complicated thing, since it has 4 tracks going in at the top, and they merge into 2 tracks halfway. There's also a secondary exit which will add a lot of variety to the running of trains, and basically makes the layout seem much larger than it actually will be. There will also be several block within the helix itself, multiple trains can be in the helix on their way to the yard. This makes the main station (which will be connected pretty much directly to the 4 tracks going into the helix) more interesting, since trains won't have to wait for the preceding train to have cleared the entire helix.

 

The innermost track oval (which isn't visible on any of the images for now) is about 330cm long, so I went with a 6cm clearance between the layers. I could go a bit lower and decrease the slope, but right now it's just below 2%, which is well below the recommended minimum for pretty much all trains.

 

 

Image 00:

The track plan. The left most oval is the top layer, rightmost is the bottom layer that connects to the yard.

 

Image 01:

Frame for the helix (minus a couple of bits here and there)

 

Image 02:

First test track, also testing with some of the more challenging cars (the heavy transport and rail crane)

 

Image 03:

Servos are top-mounted rather than underfloor. Underfloor would work for the bottom loop, but for other loops it's mean the servos would be in the way of the trains. I installed them in such a way that the servos themselves are easy to replace if needed.

 

Image 04:

First loop installed.

 

Image 05:

Continuing to build up the layers.

 

[cteno4]

Wow, now that is a helix layout! Nice work Martijn!

 

Jeff

[JR 500系]

Oh wow! Amazing work!

 

Can I know the gradient of this? It looks great having the trains run up a long loop~~  :)

[Martijn Meerts]

It goes up 6cm per loop, and a loop has a track length of about 330cm for the innermost loop. So it's about 2% for the innermost loop, less for the other loops.

 

I can go down to about 5cm per loop, but I really like having a good amount of space in between the loops so I can actually reach in in case something happens, and well, 2% should be doable for pretty much all trains I have.

[Martijn Meerts]

Progress is slow (as usual), and no new pictures. However, I've started working on the 3rd loop, with the set of turnouts and crossing in it. Connecting these will be interesting since not only do the frogs on the turnout need to be polarized, the both frogs on the crossing need it as well. Luckily, Peco's crossings look to be pretty straight forward and need to modification. It also comes with some wires already in place for both general power and power to the frogs.

 

I've also done some test running on the first 2 loops and had to adjust the height a bit here and there. I tested with Kato's GG1 with all 14 of the Broadway Limited cars. It pulls up without any issues whatsoever. At some point the loco had derailed while I bumped into the module. The front bogie was completely off the track. Even with only 1 bogie on the track, it still ran up the helix until the derailed bogie got stuck on a screw ;)

 

I also tested the E5/E6 combo, initially with only the E5 motor car. It did have some issues getting up at a section where my measurements were off and the track was a bit steeper than it should be. Other than that it ran well. I then installed a decoder in the E6 motor car as well, and ran the combination with both motor cars. Went up just fine, even on the steeper bit. Even at high speeds they run through just fine.

 

Like I said, progress is slow, mainly because I can get some real work done on it during the weekends, but also because every time I add a section I need to wire it up temporarily and test electrical connections and everything. If I mess up somewhere, it's going to be a pain fixing it once the entire helix is installed. I should at this point probably also get an occupancy detector and test-install that one before I continue much further. I'm about 99% certain it'll work, but there's always that 1% ;)

[Martijn Meerts]

Well, as is starting to become rather common, I managed to mess something up while building the helix, so I'm now back to 1 loop rather than the 3.5 loops I was at before the weekend ;)

 

Problem was that I had the insulating rail joiners on the wrong side of the track. Now, that wouldn't have meant that the layout/occupancy detection wouldn't work, but it'd end up being really confusing having the insulating rail joiners on 1 side of the track for the entire yard (and rest of the layout eventually), and on the other side of the track for the helix. Luckily, it's a fairly quick fix, just that I had to remove 2.5 loop worth of helix to get to the bottom sections of the track.

 

Rather than build the entire helix at once, I'm going to be building 1 loop and then wiring it up completely, including occupancy detection, before going on. Just in case I make another mistake. Don't really feel like taking it apart more than once :)

[Martijn Meerts]

Managed to get a little work done on the helix the past weekend/days. Not all that much unfortunately, due to work, but at least it looks like there's some progress.

 

I've fixed the previous mistake (I hope), and have started rebuilding and wiring the thing. I'm only temporarily wiring it now for testing, the final wiring is going to be rather complicated and I rather want to have the entire helix built up so I know where all the wires are and how many of them there will be. There's actually not that much space because the middle of the helix needs to be kept without any wires at all so I'll always have easy access.

 

 

Image 06:

2.5 loops are done, working on the turnouts and crossing that splits the tracks (2 are exit tracks leaving the helix, the other 2 will continue) The turnouts and crossing are wired and installed, just need to install the 2 servos for the turnouts. Also added part of the 4th loop to see how it looks. I'll need to see if I can get some more wood cut this weekend though, missing 1 loop worth.

 

Image 07:

Turnouts and crossing. The crossing is an electrofrog one (just like all turnouts), so I need to wire the frogs and make sure they're polarised correctly. Probably needs some trial and error, since each frog needs a different polarisation.

[cteno4]

Dude this is one serious helix!

 

Jeff

[Ochanomizu]

Hello,

 

I am curious to know why helix is so large?

[Martijn Meerts]

It's not really that large is it?

 

The reason for the size is that 16 car shinkansen should be able to go up and down the helix, meaning I needed to use a minimum radius.

 

The reason it has 4 tracks part of the way, is that the train station that will be connected directly to the helix will have 2 shinkansen and 2 regular tracks going into the helix. I could've let them come together to 2 tracks before going into the helix, but with 4 tracks there will be more train movement going in and out of the helix.

 

The height is because it needs to go down enough to be able to reasonably comfortably reach the hidden yard which will be directly underneath the main station.

[Ochanomizu]

Hello,

 

Sorry, I asked wrong question: I am curious to know why helix is so large tall?  You have four laps around the helix.  Do you really need such space between your storage yard and layout?  If the space is to make it easier to handle trains on the yard, how would you handle a derailment in the middle of the helix?  Also, what are the dimensions of the outside track and space between levels?

 

It certainly looks like a $1000 helix to me!

[Martijn Meerts]

It's that tall because the frame of my modules/sections have sides that are about 14cm high (so I can install all the digital components without them sticking out from the bottom), and the main station is most likely going to be an elevated one, so there's the added height of that. I did some height testing with the yard and the sections going over the yard, and decided on the amount of levels based on that.

 

A derailment in the helix itself isn't much of a problem if it's only 1 or 2 cars, there's enough space in between levels to reach in and re-rail them.

 

For the curves I've used the Finetrack system as a general idea for the radius even though I'm using Peco flex track. So it's (inside to outside) 317mm, 354mm, 391mm and 428mm. Clearance between levels is 6cm at the moment, might decrease it slightly depending on how well trains go up the slope, although no trains should have issues with it, it's not very steep at all.

[kvp]

Could you give us an overview plan of your planned playout? I also would like to ask what is the reason behind choosing a helix versus a ramp at the back? So far i've understand that you will have a quad track entry point, a double track entry point and a double track yard connection at 3 different levels.

[Martijn Meerts]

I could post an overview of the layout plan, but I don't actually have one beyond a very general idea of what the station should look like. Actually, I do think I at some point posted the dimensions of the train room and some early ideas, but I can't find them anymore.

 

edit: found the thread: http://www.jnsforum.com/community/topic/4630-new-layout-ideas/

 

 

Reason for the helix is that a ramp wouldn't be very practical due to the height difference from the layout to the yard.

Edited January 29, 2016 by Martijn Meerts

[kvp]

Thanks! I see that you have changed a few bits from the original plan, like adding an elevated cape gauge station while keeping the ground level one and mixing the four yard access tracks into a single double track line instead of having two separate yards. Imho this will be an interesting and quite large layout.

 

Some ideas for the peco turnouts:

-if you can avoid it, don't solder to the bottom connecting wire, it tends to brake off easily, it's better to add the frog power wire to the two frog rails just before the isolators

-you can power the frogs of the crossing from the same circuit that polarises the turnouts as long as you switch both tunrouts in synch (and the frog power output is bipolar)

-if you don't want that, then an automatic loop module can be added to switch the frogs between the two polarities

 

ps: Some of these modules can be used to switch the turnouts in the trailing direction by adjusting the position together with the frog polarity or you can use the occupancy detectors and some logic to set the routes automatically and to prevent a side collision accident. Switching the up and down (literally) routes together eliminates the problem, but doesn't allow traffic at the same time on the two side routes that avoid the crossing.

[Martijn Meerts]

I don't really have any real plans for most of the layout, but the station like shown in the last design in the linked thread is about how I want it to look. 4 shinkansen tracks (possible with a shorter stub track for shorter shinkansen) Might go with fewer tracks for non-shinkansen, but I'll figure that out once I start building the station. Track planning software is nice, but in the end physically putting down the track gives you a much better idea of what's doable and what isn't. 

 

The large station will also pretty much be the only part of the layout where shinkansen will be visible. I do want them on the layout, but I don't want to dedicate the layout to them. 

 

I don't use the connecting wire on the Peco switches. I solder on several wires for power and polarisation directly to the track. For the crossing, I have soldered to the pre-installed wire, but once installed and wired up, there isn't going to be any movement, so they shouldn't break. For frog power I'm using the Switchpilot Extension, which takes care of it all. It also allows you to program exactly when the power switches. For the crossing, I'm going to use the same, except the frogs need to be powered separately (which is possible with the Extension). Turnouts going into the crossing will programmatically always be switched together.

 

Layout will be computer controlled for the most part, so I'm not too worried about accidents. They will happen of course, but only when I mess up the programming really ;)

[kvp]

 

For the crossing, I'm going to use the same, except the frogs need to be powered separately (which is possible with the Extension). Turnouts going into the crossing will programmatically always be switched together.

This means only one switch pilot DPDT relay is needed for the 4 frogs. (i would go as far as to use a single servo to move both turnouts, but that works reliably only if you have the turnout springs in place and power off the servo after switching, this trick works with two servos powered from the same output as long as you switch frog power exactly in the physically middle position)

[Martijn Meerts]

I've thought about going a single servo for both turnouts, but there are some reliability issues, as well as potentially replacing a broken servo being somewhat more challenging.

 

Since I use an ECoS (and eventually computer control) I can easily make sure I always switch both turnouts at the same time, so that's not really going to be an issue.

 

 

I'm actually more worried about designing the rest of the layout then I am about wiring and possible collisions and all that :D

[Ochanomizu]

Thank you for explaining the situation.  It appears my first problem was one of scale.  It looks so big in the photos.

[Martijn Meerts]

Progress is still a bit slow, it's a rather good amount of work getting all the track done, and the bits with the turnouts and crossing took quite a while to get right.

 

 

Image 08:

 

A quick wiring test of the first set of turnouts and crossing. Red and blue are just power, green are wires that go to the frogs. Each turnout has 1 green wire, and the crossing has 2. Turnout 1 (the top one in the picture) just controls the polarisation of itself. Turnout 2 controls polarisation of but itself and the crossing. The polarisation of the crossing needs to alternate, so if 1 end gets positive (red), the other end needs negative (blue).

 

The decoder is the ESU Switchpilot Servo with the Switchpilot Extension. The extension is made for doing polarisation, and in combination with the Switchpilot servo, it allows you to set it up so that power to the frogs is switched when the turnout is actually half way to be thrown, that way you prevent any chance of a short.

 

 

Image 09:

 

Current state of the helix. Just a little more than 1 full loop left to go :)

 

[beakaboy]

Wow! Very busy, but also very cool. I myself ,don't recall seeing a 4 track helix before

[Martijn Meerts]

There are a bunch of them around on larger layouts, but most do seem to be either 1 or 2 tracks. Of course, not the entire helix has 4 tracks, it's really only the top 2 loops, the other loops have 2 tracks. I could've gone with 2 tracks, but I just wanted a somewhat more steady flow of trains in and out of the station.

 

 

 

Not much progress recently, but I did prepare the 2nd set of turnouts, just need to install the servos now. The remaining track should be fairly straightforward after that. I'm thinking 2 weekends of work should do the trick. Of course, after that, it's wiring the whole thing ;)

[kvp]

I think this is a huge amount of work to be fully covered up. Do you plan to make at least some of it visible?

[Martijn Meerts]

Right now the plan is to have it fully covered up at least. A helix doesn't really lend itself well for scenery, especially not one that goes to a yard below the layout ;)

[cteno4]

nice plex window on the front to watch the trains spin up and down!

 

jeff