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September 18, 2016 New Daylight Observation Car

Sometimes I'm just slow on finding out correct information about my favorite Railroad, the Southern Pacific. 

While surfing for SP info I ran across a rather interesting fact, the SP Daylight Observation cars had a backup light top center!  For years I thought the SP Observation cars had three rear marker lights.  I guess I could just change out the rear light but my Athearn car looks so good I didn't want to screw it up so I bought a new unassembled Athearn kit off eBay.

My 25 plus year old Observation car doesn't have much of an interior so I will include that in the new car.  Because I operate my layout dual mode DC and DCC making the rear backup light operate will require a DCC decoder in the DCC mode, this car will be for my DC operation passenger service.  I use a 4 volt lighting system on my passenger cars so the new car will also have LEDs operating on 4 volts.

Controlling the Backup light will be super simple using a mini 5 volt relay with a diode sensing track polarity for reverse.  I will use a 2mm warm white LED for the rear light and use the 4 volt supply for power.

Because I will need power from the rails I needed to add wheel wipers to the Athearn passenger trucks.  I made my own wipers using thin brass sheet for the base and soldered .02" brass rods to the base to make contact with the wheels.  I was against using wheel wipers until I tried them on several cabooses.  They work very good and on the positive side you end up with all wheel power pick up.

I used #36 wire between the trucks and the frame for power transfer.  The routing of the wire is crucial, large loops around the truck provides the least amount of drag to the trucks.

Next I added 3 ounces of #8 bird shot to the frame because I'm not going to use the Athearn sheet metal weights, a total weight gain of 1.6 ounces.  By using the bird shot I also gain space, the bird shot is 1/16" thinner than the two Athearn weights.

Here I have installed the frame connector in the upper right corner and run the backup wiring to the center depression where the mini relay will be.

Here the relay is wired and glued in place.

With the wiring finished it's onto the interior.

I went with 5mm wide angle LEDs for the interior lighting.  To even out the light dispersion within the interior I close spaced the LEDs and used 20KΩ ⅛ watt resistors for very realistic low light level.  The total current at 4 volts for all 9 interior LEDs is .630 ma.

The LED above the bar area is a bit brighter, I used a 10KΩ ⅛ watt resistor for it.

As per my standard electrical plan I use the Micro Connectors for all of my lighting.  You can see the three pin male connector glued to the rear wall in the left corner of the frame.

The male shell connector drops into the female connector when the shell is in place, NO messy wiring to contend with.

I found a floor plan for an SP Daylight Observation car online while surfing so that will be my guide.

I made a 1:87 scale printout of the floor plan to make it easier to fabricate the interior.

Here I have constructed a first run at the interior and airbrushed the shell.  Because the Athearn car is shorter than the real thing a few interior seats have been left out.  The interior floor is .02" thick Styrene sheet, using thin Styrene helps save floor to ceiling space.

I bought two sets of Precision Scale passenger seats to build up the interiors for the Observation car and the SP Tavern car kitbash.  The seats are correct size for 1:87 scale.  The two pieces in the picture are one seating kit.

After painting with Crafters Acrylics it's taking shape.

The Tables and the bar are constructed from .020" Styrene sheet.

Now comes the time consuming part, painting the Preiser #16358 seated passengers.  There are 72 different figures in this package.  I use Cafters Acrylics with a Winsor & Newton Series 7  3/0 fine tip brush.


I attach the figures to the head of a pin with super glue for painting.  I use erasers for easy storage during painting.  To make it as easy as possible to paint the ¾" tall figures I stick the pin in a pencil eraser for a holder, that makes them easily rotatable for painting.

In the past I've always used small wire insulation for glasses, but this time I tried 1mm fiber optic cable, it's the correct size for a 3½" diameter glass.  The fiber optic glasses look much more realistic than painted wire insulation.

The older I get the harder it is to paint 1:87 scale figures, these took an average of about 20 minutes each.

I spend more time correcting brush slip errors now because of my old age shaking.  After about 90 minutes using the fine tip brush I get the hang of it and the painting goes a lot better.


The interior is finished and the lighting level looks good so now onto the marker lights and the forgotten backup light. 

My intention is to use 2mm fiber optic cable for the red taillights but my order has been lost in the mail so my project  will have to be put on hold until it arrives.

To be continued when the fiber optic cable arrives. 

Well after almost two months I finally received my order for 2mm fiber optic cable and I'm moving along with finishing my Athearn Observation car.

I mounted the 1.8mm backup LED top center and super glued a 1¼" long piece of the 2mm fiber cable to a pair of red 1.8mm LEDs.

I ended up using 1K resistors in series with the LEDs, the LEDs draw just under 5ma at 4 volts.

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