Although the museum is still closed, the situation here is somewhat relaxing; consequently Jim and I ventured to the museum to do some much needed track cleaning -- our concern was that many months of non-usage would make the track harder to clean, and we believe some regular maintenance will help avoid downtimes when it is time to re-open. Luckily we completed that task without any difficulties.

I have using this workflow for light track cleaning with good success:

A Shelter-in-Place Order was issued Monday March 16, 2020 for the City and County of San Francisco and other Bay area counties and will remain in effect until April 7. The Randall Museum is currently closed to the public and is in between used for the Emergency Child Care Center effort organized by the city.

More information here:

• https://www.randallmuseum.org/randall-museum-update-3-18-2020-regarding-shelter-in-place/
• https://sfmayor.org/article/san-francisco-issues-new-public-health-order-requiring-residents-stay-home-except-essential
• https://sf.gov/information/san-francisco-converts-rec-facilities-emergency-child-care-centers
• https://sf.gov/topics/coronavirus-covid-19

As a volunteer, my presence there is non essential. I have a lot of work pending on the layout that will just have to wait.

From a technical point of view, that means the layout will not run for many weeks in a row. That may be a problem as tracks oxidize and gather dust when there are no trains running for a long period of time. Thus I fully expect we (and by “we” I mean essentially just me alone) will have to spend quite some time going in there and manually scrub the track to make sure trains still run smoothly. Some folks naively think it’s as easy as just running a track cleaning car, and my experience is that nothing beats actual elbow grease to scrub the track in the accessible areas.

I could ask the museum staff to run the trains once a week. I’m going to venture that they have reduced staff numbers and more urgents things to focus on. And even that would just induce a different issue, namely that all that dust accumulates over time as gunk on the train wheels. We need to clean them monthly or it can become significant enough to derail them.

Description of Issue

The turnout T151 has been repaired:

These are Fulgurex slow-motion turnout motors. They are mounted on the layout using an aluminum bracket for support and alignment, with wires to switch the polarity of the frogs. Very neat job done eons ago:

The symptom was the point not moving, even though the Fulgurex motor had power. This one is on the cross-over that goes from the mainline to the Napa / Richmond yard access:

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:

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:

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:

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

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:

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:

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.

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?