Model Railroading > Light ‘Em Up! (Part 3) – Frankenstein's Locomotive

My first attempt at installing Lighting Details was to use a light source already installed on the chassis.  Ideally, the LED would be on when the engine sound is running.  The most likely candidate was the headlight.  The LED that illuminates the headlight is located high on the chassis, at the front-end of the motherboard.  It is pretty bright, and should have enough “extra” capacity to feed some fiber optics. 
 
This scenario implies this is the lead (or only) engine in a consist.  Otherwise, the headlight would be OFF and the Lighting Details would not be illuminated.  This is not prototypical, and won’t keep crews safe at night.  The purpose of modifying this specific engine is a “Proof of Concept” for the use of fiber optics to act as a Light Pipe to implement the Lighting Details.
 
Reluctant Surgeon
This was going to require a significant amount of surgery on a brand-new Tunnel Motor.  I’m reluctant to disassemble engines due to the possibility of breaking-off parts or other damage.   A purchase from the very first run of ScaleTrains Tunnel Motors is D&RGW 5369.  I just happened to snap some images of the prototype back in the day when railfanning.  While in a siding, I could take a set of 360-degree walk around images.  This documents the equipment, paint scheme, weathering, etc. for this specific unit.  It is pretty rare to have a dead-on match for the road number offered by a manufacturer, so I was very happy to find a hit among the Tunnel Motors I documented.  I wanted to Speed Match this unit, and it was making some breaking-in laps on the test track. 
 
Air Borne
Little did I know it, but one of the clip-together track sections was slowly being forced apart.  (I know, I should have glued the sectional track to the foam base.  But I figured the clips would hold, and I wanted to run some trains.  BIG Mistake!)   Eventually the gap grew so large that the wheel flange jumped the track and was on the ground.  I could hear the dreaded sound of metal wheels on plastic ties.  In the good ol’ days, the engine would have lost track power, and come to a stop.  But, the current keeper maintained power.  (One of its purposes is to maintain power when bad track is encountered.    Even track as bad as mine…)   As (bad) luck would have it, the engine was on the other side of the test track, far beyond my reach.  I grabbed the throttle to press the Emergency OFF button, but it was too late.  I watched helplessly as D&RGW 5369 left the track and disappeared over the edge.  For what seemed like an eternity, the only sound I could hear was the speaker, dutifully creating wonderfully realistic prime mover sounds, even though it was nowhere near the track.  Then came the inevitable crash…BOOM!  The sickening sound of a brand-new engine meeting a concrete floor, at terminal velocity.  Then there was the tinkle of all the small parts that had been traumatically amputated from one of my favorite locomotives.  :-O
 
I See Nothing!  I Hear Nothing!  (Sgt Schultz – Hogan’s Heroes)
I stood there for a moment in shock.  Did that just happen?  Maybe if I just ignore it, everything will be fine.  But eventually, I did go around to the other side to have a look.  I stepped carefully so as not to crush any of the shrapnel scattered on the floor.  Engines are heavy to increase their tractive effort.  However, this weight also increases the kinetic energy during free-fall.  The only thing to dissipate this energy are highly detailed plastic parts.  Needless to say, it was NOT a pretty sight. 
 
Crash and Burn
The point of impact appears to be the rear steps on the conductor’s side.  The corner of the pilot was snapped-off and found a few feet away.  The rear steps had collapsed like an accordion.  Ends of the air hoses were sheared-off, nowhere to be found.  The rear truck disconnected from the gear tower, with the worm gear and drive shaft exposed.  (Viewing the “internal organs” hanging out like that was a bit traumatic!)  After destroying that corner, the engine must have pivoted and landed on the cab roof on the conductor’s side.  The entire cab was shifted-over by about ¼” towards the engineer’s side.  Most of the window panes were cracked.  The LED enclosure behind the cab had its mounting pins sheared-off, and was dangling by the wires.  After carefully gathering all the chunks and pieces from the floor, I had to take a break and walk away.  Part of it was to mourn the loss, and the other part was to beat myself up for allowing poor trackwork to wreck one of my favorite engines.  :-(
 
Back From the Grave
While recovering from this painful experience, I considered the options.  D&RGW 5369 could provide spare parts, since ScaleTrains does NOT offer them.  (In the good ol’ days, an exploded diagram from Athearn provided a source of part numbers to order parts.  Not so with ScaleTrains.)  However, I didn’t want to just send it to the scrap heap for parts.  I REALLY liked the idea that the road number matched one from my image library.  It would save time required to renumber another unit.  After being able to calmly survey the damage, I realized I had found the majority of parts.  Missing parts (or ones that were beyond repair) would be 3D printed (or come from other engines).  Some weathering would hide most of the scars.  I resolved to save D&RGW 5369 from the dead line.  (Sorta’ gives a new twist to the term “kitbashing”.)  The good news is, D&RGW 5369 had just volunteered to be the Tunnel Motor I would use for the extensive surgery required for the fiber optics install.  I figured that no matter how much damage I caused while I modified it, I couldn’t make it look much worse!  :-D
 
The cab was pretty much already removed (the trip to the concrete floor took care of that!), so that was an easy step.  I could see the stock Light Pipe used to transmit light to the headlight (in the roof of the cab).  There was a slight bit of room to each side of the Light Pipe.  A 1/16” drill bit made a hole that angled down into the cab interior.  The purpose is to provide a path for a pair of fiber optics to accept light from the LED, enter the cab interior, make some twists and turns, and finally transmit light out the end for the desired Lighting Detail.
 
Grounded
The Ground Light’s job (as the name implies) is to cast light onto the ground beside the cab.  At night, this gives the crew an idea of the train’s speed, especially when trying to judge wheel-slip on grades.  Ideally, a portion of the ground is illuminated, as well as the side of the truck.  The tip of the “bulb” should be barely visible.  The choice of 0.75mm fiber optic diameter was driven by its ability to not only transmit light, but to do it with enough intensity to “throw” light to illuminate an area.  This is particularly important for the Ground Light.  It is normal for some light to be lost during transmission thru fiber.  This can be used to advantage, since the intensity of the headlight’s LED is quite bright.  The Ground Light is about a 60W incandescent bulb equivalent, so the trip thru the fiber will tone it down a bit.  The end of the fiber optic is slightly off-center (relative to the LED), which reduces the amount of light accepted by the end.  By the time the light zigzags thru the cab interior, the amount of light should be about right.
 
Black Out
The sides of the fiber emit a trace of light.  This is not visible with the room lights up, but in darkness it looks like a glowing noodle has invade the cab.  A coat of paint (AccuPaint Gloss Black) provided the necessary light block.  The trick was to apply the paint without contacting the white walls of the cab.  (In hindsight, it would have been better to paint the fiber BEFORE installing it.  Even if some rubs-off during the install, that can be touched-up.) 
 
The Big U-Turn
At the other end of the locomotive is a rear step light.  Usually, a fiber run is a few inches.  For this run, if the fiber was laid-out flat, it would be longer than the entire engine!  Again, 0.75mm was chosen in order to transmit as much light as possible.  The fiber starts at the same source LED, enters the cab, then goes thru the floor in front of the engineer.  It enters the void under cab and exits the sill under the cab steps (behind the engineer).  The hole in the sill was drilled at an extreme angle (as close to horizontal as possible) in order to allow the fiber to hug the sill.  The fiber was threaded amongst the other hardware and components under the sill.  CA glue was used to hold it in-place.  At the rear steps, the fiber was incrementally bent (with a pair of small needle nose pliers) into a gentle 90-degree curve.  (This was to see how it compared to the Hot Water method.)  For gentle sweep bends, it works fine.  After a coat of black paint, it blended with the rest of the plumbing.  The result was quite reasonable.  A mellow glow keeps the crews safe when climbing the rear steps.  (They are actually more like a ladder, but “rear ladder” make it sound like a 1950’s box car.)
 



Edited 4 time(s). Last edit at 03/09/25 15:03 by tmotor.

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It's Alive!
This project serves as an R&D test bed.  Before doing a detailed install, this rough beta version helps confirm the project is on the right track.  If it misses the mark, then it is time for a course correction.  The conclusion from this exercise was that fiber optics can transmit light a long distance.  Since the LEDs (and associated wiring) will be attached to the chassis, this provides a means of taking the light from the source and delivering it to where it is needed.  My preference is to use fiber optics to provide the light, vs. running pairs of wires to 7+ LEDs all over the shell.
 
One thing I didn’t like was the exposed fiber snaking thru the cab interior.  Though it was hard to see during the day (and nearly impossible at night), it spoiled the look of the full cab interior. New LEDs dedicated to the Lighting Details would allow their location to be mounted lower on the chassis.  This not only cleans up the cab interior, but reduces the length of the fiber runs.
 
Pump Up the Volume
I wanted the Lighting Details to be subtle, but when viewed in low light, it wasn’t as visible as I liked.  (Perhaps they are a bit too subtle.)  There was some light, but I wanted more of it.  With dedicated LEDs, the intensity will be dialed-up a notch.  One nice feature of the Output Terminals (the solder pads on the motherboard that drive the LEDs) is the intensity can be cranked up or down.  Therefore, having a too-bright LED installed is better than one that is too-dim.  If the amount of light coming out of the end of the fiber is too bright, the LED’s brightness can be dialed-back until it is at the desired level.
 
Dave
 



Edited 3 time(s). Last edit at 03/09/25 07:00 by tmotor.

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> Black Out
> The sides of the fiber emit a trace of light. 
> This is not visible with the room lights up, but
> in darkness it looks like a glowing noodle has
> invade the cab.  A coat of paint (AccuPaint Gloss
> Black) provided the necessary light block.  The
> trick was to apply the paint without contacting
> the white walls of the cab.  (In hindsight, it
> would have been better to paint the fiber BEFORE
> installing it.  Even if some rubs-off during the
> install, that can be touched-up.) 

One trick I've heard is to paint the fiber silver, then black. The silver serves to reflect the light back into the conduit (mirror effect), then paint as needed to hide the fiber.

Posted from Android

Darren Boes
Lethbridge, AB
Southern Alberta Railfan

Greetings Darren!

> One trick I've heard is to paint the fiber silver,
> then black. The silver serves to reflect the light
> back into the conduit (mirror effect), then paint
> as needed to hide the fiber.
That makes sense!
I will try that next time.
Thank you for the Pro Tip!  :-D

Take care and God bless!
Dave

I'm always concerned about trains going over the edge to a crash on the floor.  I didn't even test run any loco's the mainline until I had enough scenery or "guardrails" in the form of fascia lip to hopefully catch anything that comes off the rails. It appears you have the skills to put humpty dumpty back together again.

Cheers,
Jim

Greetings Jim!

> I'm always concerned about trains going over the
> edge to a crash on the floor. 
It is a universal fear shared by all of us.  :-0

> I didn't even test
> run any loco's the mainline until I had enough
> scenery or "guardrails" in the form of fascia lip
> to hopefully catch anything that comes off the
> rails.
Smart!
I have some new Tunnel Motors on their way from ScaleTrains.  
Before they make any laps on the test track, I'm going to install some guard rails.  (Probably clear Plexiglass.)

> It appears you have the skills to put
> humpty dumpty back together again.
Reluctantly, Dr. Frankenstein at your service.  :-D

Take care and God bless!
Dave



Edited 1 time(s). Last edit at 03/09/25 08:11 by tmotor.

I am not into the modeling side, I have to say, nicely done!

When you mentioned chopping of the engine I reared back from my computer screen until you mentioned it had taken the deep fall to the cement floor.  Then I started breathing again.  Those engines are so good I would hate to see anyone lose one.

Greetings Mike6640-2!

> I am not into the modeling side, I have to say,
> nicely done!
Thanks for the positive feedback!
It is basically a "kit", with some battle damage.  :-D

Take care and God bless!
Dave

Greetings tomstp!

> When you mentioned chopping of the engine I reared
> back from my computer screen until you mentioned
> it had taken the deep fall to the cement floor. 
> Then I started breathing again. 
LOL
Believe me, once an engine decides to escape the confines of the layout and hits the floor, the novelty of the "newness" wears-off.  :-0
The silver lining is the knowledge I gain modifying this engine builds my confidence to modify others.

> Those engines
> are so good I would hate to see anyone lose one.
Agreed!
They are Contest Quality, right out of the box.  

Take care and God bless!
Dave

I feel your on the lack of STX parts. I need a side frame for a SD45, and they told me they can not supply one.

BTW, if you want to paint those bright yellow rerail frogs a more appropriate shade of yellow/orange, Tru-Color CP Action Yellow is a pretty close match.

Greetings M-636!

> I feel your on the lack of STX parts. I need a
> side frame for a SD45, and they told me they can
> not supply one.
I get how it is extra work for them to stock parts, but I think most folks would be willing to pay whatever they ask.  Sure beats having to purchase a whole other engine(s) just for parts.  

> BTW, if you want to paint those bright yellow
> rerail frogs a more appropriate shade of
> yellow/orange, Tru-Color CP Action Yellow is a
> pretty close match.
Thanks for the tip.  (The stock color is pretty loud.)
By the time I shot my images, many of the rerailers were replaced with the smaller version, or missing.

Take care and God bless!
Dave