Building a GP9 in Proto:48

[ednadolski]

BTW another option this gives me is to remove the sound decoder entirely from the loco, and hook it up as a stationary decoder to drive a set of bookshelf speakers.

Ed

[wmcbride]

Pretty slick!

Thanks!

Bill

[Signalman63]

Hey there,

I'm new to this site, but I came across it when I was looking into ways of chopping an O scale GP-9.  You have done a nice job so far and the product you are making looks great.  I too am looking into Finescale proto 48 as the detail is awesome.  I'm a railroad signal maintainer, and I work for a private contractor that holds contracts with the G & W railroad systems, and I've been into trains all my life, so at 50, I've seen quite a few changes in railroading from a boy to now..............I wish we still railroaded as they did back in the mid 50's to about the early 70's.  Technology has taken a lot out of the railroad industry as it used to be, but it has also changed some things for the better.  I don't know, maybe I'm just to old school. (lol)

I'm looking into doing the same thing as you with the GP-9 project except I thought about doing it with Atlas GP-7's (still on the fence whether to use Atlas or Red Caboose) with the P&D drives.........any thoughts on this?  Your sound card and sound system you have chosen and used is spot on when it comes to the prototypical sound of a geep 9, I was really impressed with the quality as I have heard others with little to no excitement. 

Would you be so kind as to make a material list of the products you have used and are yet to use, as I want to do the same.  I hope to see more photos as your work progresses.  This is a really nice locomotive you are making and I just wish to learn more.  Great job so far! 

[ednadolski]

Hello Signalman63 and thank you for the kind words!   To try to address your question, I personally would choose the RC over Atlas, as the P&D Pittman can-motor drive train is inherently superior to the Atlas twin-motor "China drive" (which is designed to suit the 3-rail market, so it runs like a jackrabbit).  The P&D brass trucks are extremely well done and have working suspension, and Protocraft has a P:48 conversion kit that also allows the truck to be narrowed to prototype width.  I was really surprised at how much difference that made in the appearance.  Atlas bought up the RC tooling a few years back, so the shell AFAIK is the same, but Atlas has made their own chassis/frame/trucks/details.  I'm not sure what parts to use for converting the Atlas to P:48,  that likely would take some work (best to check with NWSL).

As you can see the RC option is lot of work and a lot of cost.  Expect the costs to at least equal the Atlas model, probably more once you add in all the detail parts.  BTW some of the plastic detail parts in the RC kit are pretty delicate (like grabirons and lift rings), so I made my own from brass wire or used brass parts from Precision Scale.  The RC handrails are a challenge because they are made from a plastic that is hard to paint.  I'm planning to make my own windows plus my own lighting using SMD LEDs for the headlights and ditch lights.

If you've never done Proto:48 before then the best way to start is check out the Proto:48 modelers group on Yahoo Groups, and the home page at http://www.proto48.org/index.htm.

HTH,
Ed

[ednadolski]

The bulk of the painting and graphics are done.  The decals are Microscale plus a custom set from Highball Graphics.














You'll notice in the one pic that the panel in front of the battery boxes on the conductor's side is showing a nasty crack.  This is my own stupid fault from some very careless and clumsy handling (where is the icon for kicking oneself?).    It's back in one piece, but I have to hide/disguise the crack.   Part of it will be covered by a stanchion, which helps a bit.


Here is what the shutters/grilles look like when painted and installed.  At some angles you can see clear thru & out the other side (or where the numberboards are supposed to go).  I know I've said it before, but you really have to see these in-person to get the full effect of the 3D look.

https://i.imgur.com/pFqUHdK.jpg






Here is the 48" dynamic brake fan, weathered prior to assembly.  If you blow on this thing, it will spin freely:





Next up is (literally!) a "plate full" of detail parts:




The cut levers are hand-made from wire (as you can see, they are not quite finished).   I really get a kick of of the MU hoses, these are made from individual PSC glad hands and "hoses" made from black wire insulation:




I roughed up the "hoses" with some fine sandpaper to knock off the shine of the plastic insulation, and hopefully give a bit of tooth for the weathering to stick.


There are still more details to come after these.   I will be making the windows from clear plastic sheet.  The lighting will be made from small SMD LEDs, I may have to grind away a bit of the frame in order to make a place for the wires to run.  The kit does come with plastic stanchions & handrails, but I am also considering the cast brass ones with handmade wire for the handrails (that part of it is much like N scale!  ).


I'm pretty pleased with how this build has gone so far.  Thanks for looking, hope you enjoy this! 

Cheers,
Ed

[wazzou]

Great job Ed.  The paint looks light in the photos.  Was your goal to mix it light for a pre-weathering fade?
How do you think it compares to the prototype color?

[ednadolski]

The paint color was a real hair-puller every step of the way.  So much of the outcome depends on the lighting, and you can see that these pics also tend to be overexposed because of all the black areas on the model.

I don't know how many shades of blue I ended up trying, but I did fully strip the model from the first TCP "MRL Blue" that I tried.  It just looked way too green and drab to my eye.  I grew too seriously hate it before I had even finished cleaning it all out of the airbrush.  I don't think there is any color in any brand of model paint that would look correct, right out of the jar.  I have several other MRL models and the blue is different on every single one -- not even close.  And there is no "correct" proto pic to go by: the 132 is after all covered in a substantial layer of grime, and again the tones vary depending on the lighting and angles that were used to take the pictures.  There is also the fading as pics are taken at different times over the life of the unit.  Someone even offered me a sample of the actual MRL blue paint, but one lesson I learned is that actual proto colors do not "scale down" to models (and no way I could airbrush the actual 1:1 paint  ).

The turning point for me was realizing (after looking at my 7idea MRL videos  ) that looking at the proto sitting in the sunlight isn't just the paint color that we perceive.  The color picks up the lighting and reflections of the sky, clouds, weather and surroundings.  Even the new/clean units look very dark indeed in cloudy and snowy weather. So I had to find a color that was not the proto color, but something that looked (to my eye and under my indoor lighting) approximately close enough to the perception of what the blue on the MRL units looks like when recorded on video under a bright sunny sky.  All of which is a whole lot of hot air that boils down to: (a) it's a totally subjective call, and (b) you can't trust pictures anyway.

Even that was not the end of the adventure.  I mixed up & tested some custom tones until I found an acceptable one, and then I was in for another surprise. After I painted the base blue, I sprayed a layer of Dullcote to see what it would do to the sheen, and I was dismayed at how much it actually lightened the color.  I had never seen the Dullcote do that on a factory-painted model.  Having nothing further to lose, I decided to try a layer of Glosscote, which thankfully restored *most* of the color, tho still it seems a tad bit faded looking to me.  I guess I just have to think of it a "happy accident", since now I don't have to do an extra fade coat from the airbrush.  So after adding the decals, I put a coat of the TCP Clear Flat over everything, and to my relief that did not come out with the same dramatically lightened look as the Dullcote.  I'll just have to be very careful when weathering, not to let the colors get away from me and making the model look too light.

Ed

[davefoxx]

Sometimes, I'm glad that I'm color blind.    It's easier to say close enough.  I really feel for you guys that have to struggle to find a satisfying color.  I certainly appreciate that if it's off, it's going to drive you nuts.

DFF

[ednadolski]

Here are some of the pilot details added.   The cut levers are hand made, and they work to open the knuckle just like the proto.






Here is a quick little vid showing how the couplers work.  These things are the bee's knees

Thanks for checking this out.

Ed

[davefoxx]

I looooooooooooooove those couplers.  That is so cool.  Ops sessions with couplers like those would be a lot more enjoyable than delayed magnetic uncoupling or using picks.  Nice work!

DFF

[ednadolski]

Thanks Dave!   For now at least, my ops sessions are one car and one engine, but "C'est la vie" as they say

Ed

[ednadolski]

Here is some of the latest work on this.   I've added some scratchbuilt window glass and numberboards to the cab, made from 0.010" clear styrene and glued in with Micro Kristal Klear:



Here are the all-weather window and Sinclair antenna.   There are no commercial parts for these.  So I made my own out of photoetched metal, assembled by forming and soldering.  It was a trick to form the window frame, since the metal parts being very thin frames are hard to get a grip and bend uniformly.  I'm pretty pleased with the way these came out.




Next challenge will be the lighting... 

Ed

[peteski]

Next challenge will be the lighting... 

Challenge!?  That's my favorite part of model building!  Light them up!

[ednadolski]

That's my favorite part of model building!

Cool then maybe you can help me with a couple of questions.  I'm planning to use 402 (or maybe 603) LEDs with the TSU-AT1000 with a 680-ohm series resistor for each (as per the manpage):

 - The front & rear headlights actually have two lenses so I will use two LEDs in series for each, with a smaller resistor.  I figure that wants a 390 ohm resistor for a 20 ma forward current, does that sound about right?

 - I'm using F5/F6 for the front ditch lights, but there is no separate function for the rear ditch lights.  Do you know of any simple switching circuit that could be used to switch the F5/F6 outputs to the rear ditch lights when the rear headlight is on?  Or maybe there is some other approach?

Thanks,
Ed

[peteski]

Cool then maybe you can help me with a couple of questions.  I'm planning to use 402 (or maybe 603) LEDs with the TSU-AT1000 with a 680-ohm series resistor for each (as per the manpage):

 - The front & rear headlights actually have two lenses so I will use two LEDs in series for each, with a smaller resistor.  I figure that wants a 390 ohm resistor for a 20 ma forward current, does that sound about right?

 - I'm using F5/F6 for the front ditch lights, but there is no separate function for the rear ditch lights.  Do you know of any simple switching circuit that could be used to switch the F5/F6 outputs to the rear ditch lights when the rear headlight is on?  Or maybe there is some other approach?

Thanks,
Ed

Ed, 20mA through a white LED will be quite bright.  I don't know the voltage you will be powering the LEDs with, but here is a simple calculation for the resistor value.

I assume that the Vf of your white LEDs is around 3V.  Resistor value (in ohms) for 2 series connected LEDs is:

R = (Vin - Vf - Vf) / If
"If" is the forward current in Amps.

So. if the supply voltage "Vf" is 12V and the desired current is 20ma (0.02A):
(12 - 3 -3 ) / 0.02 = 300 ohm.
 A 390 ohm resistor would result in 15mA through the LEDs.

As far as ditch lights go, if you find a decoder with enough function outputs, you could simply use 2 functions for front and 2 functions for rear ditch lights.  If not, we can come up with a circuit which will switch the same pair of function outputs between front and rear lights.