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The Randall Museum in San Francisco hosts a large HO-scale model model railroad. Created by the Golden Gate Model Railroad Club starting in 1961, the layout was donated to the Museum in 2015. Since then I have started automatizing trains running on the layout. I am also the model railroad maintainer. This blog describes various updates on the Randall project and I maintain a separate blog for all my electronics not directly related to Randall.

2020-03-07 - Automated Single Loop Run

Category Randall

Just a little brainstorming session here. One thing I’d like to add to the automation is an automated single loop run; that is place an engine which is not under normal automation, and let the computer run it for one loop, without deactivating the automation. It would have to coordinate between the two, to make sure the transient engine can only run on the shared mainline when available.

The JMRI program has block detection for both blocks B310 and B311. B310 is the “first track” and B311 is the “second track”, and the blocks start in front of the Stockton Station.

We have the Automated Freight Train parked and waiting on B311. Saturday Operators use the B310 track to run on the mainline.

In this example, I place my TGV #537 on the outside mainline track and I want it to run. Today, we have some provision for that, using the “manual” mode. It works by bringing a train to block B320 and waiting for both automated mainline trains to go in wait/idle mode. The automation changes to “manual” mode, aligns the Sonora turnout, and it is up to the operator to start and run its train. Once a train reaches Summit block B370 and then clears it by entering B380, it releases the manual mode, and automation can start again.

What I want is the same, except the run would be automated.

I can see this working in a full automated fashion as such:

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2020-03-06 - DS64 for Turnouts Control

Category Randall

Connecting a Digitrax DS64 to control both a Tortoise and a Fulgurex via DCC:

According to Digitrax tech note KB273, this configuration cannot be used as the Fulgurex takes “about 400 mA” when running, which exceeds the specifications of the Digitrax DS64 as well as ones of the NCE Switch-8.

Fulgurex and NCE Switch-8: Does not work together. I do confirm that the NCE Switch-8 cannot drive a Fulgurex directly (although it works when using the NCE Relay Board to do so).

Fulgurex and Digitrax DS64: Results are mixed. In a standalone test, I had no problem driving a Fulgurex directly with a Digitrax DS64. In situ at the museum I had one success case and one failure case. What happens is that the Fulgurex does take a lot of power, around 200 mA with a lot of variation. This exceeds the specs of the DS64. Looking at voltage, I noticed it was not symmetrical: Full 12 V voltage driving the Fulgurex in one direction but voltage dropping to 3~5~8 V when driving it in the other direction. This means we’re exceeding the current capability of the DS64 output and thus voltage drop. If some Fulgurex has a low enough impedance, it may work. If it has a higher impedance, it does not.

Let’s see how to use this. Instructions follow, let’s start with the documentation:

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2020-02-29 - Pending Work on the Layout

Category Randall

Trying to strive for a balance between work I want to do on the layout versus things I believe need to be done, coupled with their direct impact (either for operators or automation) and work complexity.

Here’s a current list:

Task

Impact

Work Load

Stockton Station dedicated Circuit Breaker

Need

Medium

Low

Mainline turnouts for Napa approach

Need

High

Medium

Fixing dead spot at Sultan

Need

Medium

Medium

Layout “cab ride” Cameras & Display for Public

Want

High

High

Computer monitoring of all Circuit Breakers

Want

Medium

High

Finish DCC control Mountain Turnout Panel

Need

Low

High

DCC control Stockton Turnout panel

Need

Low

High

DCC block detection on Valley panels 1 & 2

Need

Low

High

DCC block detection on Mountain panel 1

Need

Low

High

Automation of Fairfield area

Want

High

Very High

Automation software “Conductor” v2

Want

High

Very High

There are more tasks on my list; these are all I’d consider important for now.

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2020-02-29 - Mainline Turnouts for Napa

Category Randall

Now that I got the Napa yard fixed and working again, it’s time to use it for staging. Which means taking trains to and from the mainline..

From my own blog notes:

Let’s look at the track schematic on how to go from the yard to the mainline. The “normal forward” direction on the mainline (when operators run in a continuous loop) on this schema is from right to left:

The turnout panel on the Valley is confusing and it’s never clear to me which toggle does what:

The layout has different types of turnout motors, which are annotated on my schema. The one above is hard to read, and zooming in reveals this (with turnout numbers corrected to match actual panels):

What this means:

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2020-02-22 - Napa Yard Work

Category Randall

Work has continued on the Napa Yard, and it is now operational again! I cut expansion gaps at the end of each track (before the foam block). On the other side, by the turnout ladder, I also made expansion gaps just before the turnouts for the 3 first tracks. This should prevent rail expansion from pushing the turnout rails and shorting like it did last time. Allen contributed and he helped clean the yard by vacuuming it and running the track cleaning train.

There’s still a bit of warping on the track under Bridgeport, in the area I was not able to access easily:

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2020-02-01 - Work Updates

Category Randall

Lately I have been tackling several small tasks. In the category of “nothing to see, move along,'' I've been working on the Napa yard to prevent the track from warping again. I’ve made expansion gaps at the end of each yard track with a dremel tool. For the first three tracks that had the most warping, I have also made gaps next to the isolating rail joiner by the turnout ladder, at the other side of the track. No pictures to offer as these changes were rather anti-climatic.

I’ll continue another day as I need to similarly fix the Napa balloon track, and I need to fix a dead solder in the Napa yard track #3 while I’m at it.

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2020-01-19 - Arduino/Servos Turnouts

Category Randall

Here’s the next thing to for Randall: explore creating turnouts using servos + arduinos, to replace the old twin-coils that fail in the yards.

Let’s take the example of the Stockton yard. The ladder has 8 tracks, and about 9 twin-coil turnouts. At least 2 of them are failing -- they do still throw, but they short. The panel uses route push-buttons that align the track turnouts and the two lead turnouts. There’s a diode matrix on a panel below the yard, and I have a schema for it somewhere in a piece of paper, although that one is simple enough to just recreate the matrix by hand.

Let’s say hypothetically I’d want to rebuild the turnout machines in that yard. What are the options?

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2020-01-18 - DCC Flag Man

Category Randall

I’ve got a set of DCC Flag Man and started using them on the layout, for example here on the siding for Sultan:


A DCC Flag Man protects the entrance of the tunnel siding at Sultan

On the other side of the tunnel, the crew is working on repairs:

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2020-01-04 - Scenery Updates

Category Randall

I found some time to use more of the vehicles and houses we got from Judy’s collection:

The buildings in the mountain and to the bottom left of the picture (next to the hotel) are from Judy’s collection, and they neatly fill some empty space. Technically the mountain has an access road, yet honestly it’s not visible from the visitors’ point of view. I believe I have seen some “shrubbery” green foam around that that I ‘d like to place around the buildings’ base to make them fit better. Gaps are very obvious from up close, not so much when seen from 5 yards away.

We also got this Amtrak train from Judy’s collection. I made a video which I have yet to finish editing. In the meanwhile, the train is stopped at the Fairfield station for everyone to look at:

Some people may want to snobbishly point out this train is not prototypical; I both fully agree and would ignore that. It’s a nice setup and I’d rather have it visible that sitting on a shelf. I also think the paint scheme nicely fits together. The train runs nicely too.

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2020-01-01 - Happy New Year

Category Randall

Happy New Year 2020 from the Randall Model Railroad team.


A collage of 2019 trains on the Randall Model Railroad.


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