June 27, 2016

Fun with CNC

My friend just recently acquired a very nice CNC mill, and he was kind enough to oblige with a test cut.

On Thursday, I fired up 123Design and threw together a double-track spacing jig:



On Monday morning he handed me this:



Still some rough edges, but WOW.

February 24, 2016

Back in the Saddle & Making Tracks

Back to building turnouts for China Basin.  I decided to continue to use a very tight arrangement of turnouts with the points being close to the adjacent turnout.  Track spacing in the yard will be 1.125", as I have lots of convenient Free-moN spacing fixtures.  The prototype spacing is 14', which works out to 1.05".


Keeping the throat compact is important to maximize the capacity of of each track.  My goal is to keep the railcars for more than one float in this portion of the yard.  I need nearly 38" of track to hold a reasonable number of 40' boxcars.  Here is the experiment that drove this home— only 8-10 40' cars fit on a single piece of ME Flex, and that doesn't include necessary clearance to avoid fouling switches.




After debating a bunch of new techniques for throwbar mechanisms, I settled upon using the heavier Clover House PCB stock to provide more surface area for silver-soldered points.  Control of the turnouts will be through the use of SPDT slide switches.

January 5, 2016

Latest Track Plan

Spent some time over break working on a new track plan that actually fits in the layout space that I have.

ATSF China Basin Yard Layout

This layout is a "yard-centric" design, as there isn't really a traditional "road job" to be had.  One operating crew will handle loading and unloading any car ferry, whereas the second crew will handle switching the local industry and interchange with the Southern Pacific Railroad.

I expect the car ferry crew will be kept busy sorting cars on and off the car ferry, following the various loading and unloading rules.

The other crew will shuffle in and out of the interchange or industrial staging, and then work the  on-layout spots: Tidewater Oil, Western Car Loading, and Pier 50.  Western Car Loading and Pier 50 have specific positions, including cars which must NOT be moved within the session.  There is also a RIP track for ATSF cars needing repair.  When the switch crew is done with their pick-ups, rail cars will either depart the yard via the car ferry, or will be set out as a single block on the SP interchange track.  To vary the session, the crews could switch roles at the halfway point of the session.

Like the prototype, the entire San Francisco Terminal Division is dark territory.  The yardmaster is in charge of controlling the flow in the session. The yardmaster is also float dispatcher.  The intensity of the session can be varied be controlling the number of car floats which are involved.

There are four "spots" for staged trains, two representing the SP interchange, and two for SF industries such as American Can Co., or even the 25th street Western Pacific yard.

Remaining open design issues include dealing with any derailments while switching Pier 50.  The Pier 52 ferry slip is a separate "module" from the rest of the otherwise permanent layout, and may be mounted in such a way as to swing out to allow access.

August 2, 2015

More painting progress

Was away from home for a bit, then came back to a very busy work week. Taking some "time off" from a project is often a good thing— it makes you appreciate hobby time even more.

Today, I had a chance to test all those painting experiments from a few weeks ago on the apron:


I'm pretty happy so far, but have a LOT more to paint.

July 10, 2015

Painting Experiments

Inspired an old online article, I decided to start experimenting with techniques for painting the top deck of the ferry dock.

Instead of using RIT dye, I decided to start with a thin wash of black acrylic paint (Vallejo Model Air Black) followed by dry brush successive coats of lighter colors (Dark Sea Grey and Deck Tan).  Following another online hint, I used some yellow ochre pigment to try to warm up the deck as a final step:


I have a lot of decking to paint, so I'll probably continue experimenting with blending the PCB and plastic together in a believable fashion.

After last night's experiment, I used the remaining gray washes to create a high tide mark on the piling wall:

June 29, 2015

Weekend Update

Had some time over the weekend to continue working on the ferry dock.  With all the turnouts built, it was now time to focus on the "easy" track.

I've become quite fond of the FastTracks "plain old track" jig for making straight track— so it was time to try using it to make the straight section of the pier.  I started by making a simple section, then adding my longer PCB ties to the newly constructed rigid track:


Removing the "standard" ties, I end up with what I want:


Once I had the decking in place, I cut some scribed styrene:



...and fit the pieces between the PCB ties.



As the night drew to a close, I stood up on the chair to check my work against a prototype photo.  My dock is meant to go onto a module, so I'm purposely beefing up some of the framework underneath the deck.  To my eyes, I'm pretty close:



June 16, 2015

Getting back to work

I finally got past some work deadlines and had a chance to build the "easy" turnout for the ferry slip.  Started out with a Fast Tracks #7 turnout template, and a bit of graph paper trimmed to the contours of the dock.


Like the earlier 3-way turnout, I decided to use "extra-long" tie strips that could be blended into the decking.  After a bit of filing and soldering, I spliced the new left hand switch onto the existing track work.  I ended up cutting the ME code 40 rail joiners down to a more reasonable length, but I'm not 100% happy with their appearance.


After I was happy with the splice, I flipped the whole assembly upside down to solder additional bracing to the underside of the PCB ties:


After some tweaking, I now have all the turnouts in place on the dock:


P.S.: Yes, I know I still need to add the throwbar to the turnout.  Next up, continuing the spur that runs down the left hand pier.

April 27, 2015

Crossover indication with DTL logic…

Over on TheRailWire, someone asked if it was possible to create a circuit for indicator LEDs to properly show the crossover route if an only if the turnouts were both aligned using only the half of the DPDT contacts on the turnouts.  Here's a quick Diode-Transistor logic circuit which would use jelly bean NPN transistors (2N2222) to create a simple logic gate for the crossing route:


Both Turnouts "Normal"


One Turnout "Thrown"


Both Turnouts "Thrown"

March 18, 2015

Power routing fun

The 3-way switch has turned out to be a real head scratcher sometimes, but thankfully, I've realized a bunch of the power routing can be done with the existing DPDT contacts on a Tortoise motor.

Here is a look at the various turnout routes and how each section of rail should be powered:


The top "gauntlets" are powered just like a normal switched frog in a conventional turnout. It is just that the left and right turnouts are stacked atop each other. The center frog is powered from either the "left" or "right" routes; and dead otherwise.

Locking out the illegal route is all that is really left to do— and that can be either accomplished by clever software or hardware interlocking.


March 8, 2015

Getting to the Point(s)

Worked on the 3-way turnout again today.  Took a few iterations to tune the points as the constraints are a bit fiddly.  Thankfully the opposite points help act as guardrails and pull the car down the correct path.



The points are "interesting" as they overlap and must be thrown in sequence to set the route:





Next up will be a mechanism to throw those points.