Jan 192014
 
I've removed the cab and short hood section in preparation for attaching the blank hood and high nose.

I’ve removed the cab and short hood section in preparation for attaching the blank hood and high nose.

So, this is going to be my first attempt at a B30-7A.  It has been a long time since I’ve worked on any GE power in my shop.  But GE power was still relevant in the era of BN which I model.    I’m going to do an early B30-7A, the easy version.

The later one requires building a doghouse for the dynamic brakes on the roof of the long hood.

I have started with an Atlas Silver Series B23-7 I got off ebay, which someone so kindly undecorated for me.

Here’s my start.

Apr 232013
 

Here are a few snapshots of the TCWR 409 on my Sioux Junction HO Scale Model Railroad.  I plan to weather this unit later on this week.

The GP7 engine is by Atlas.  I cut the shell down to make a low nose geep 7 and applied paint and decals to make it look like the units in use on the real Twin Cities and Western Railroad.

The GP7 engine is by Atlas. I cut the shell down to make a low nose geep 7 and applied paint and decals to make it look like the units in use on the real Twin Cities and Western Railroad.

The GP7 engine is by Atlas.  I cut the shell down to make a low nose geep 7 and applied paint and decals to make it look like the units in use on the real Twin Cities and Western Railroad.

The GP7 engine is by Atlas. I cut the shell down to make a low nose geep 7 and applied paint and decals to make it look like the units in use on the real Twin Cities and Western Railroad.

DSC_4350

TCWR 409 rounds a bend on my Sioux Junction HO Scale Model Railroad.  The GP7 engine is by Atlas.  I cut the shell down to make a low nose geep 7 and applied paint and decals to make it look like the units in use on the real Twin Cities and Western Railroad.

TCWR 409 rounds a bend on my Sioux Junction HO Scale Model Railroad. The GP7 engine is by Atlas. I cut the shell down to make a low nose geep 7 and applied paint and decals to make it look like the units in use on the real Twin Cities and Western Railroad.

TCWR 409 on the Willow Creek trestle on my Sioux Junction HO Scale Model Railroad.  The GP7 engine is by Atlas.  I cut the shell down to make a low nose geep 7 and applied paint and decals to make it look like the units in use on the real Twin Cities and Western Railroad.

TCWR 409 on the Willow Creek trestle on my Sioux Junction HO Scale Model Railroad. The GP7 engine is by Atlas. I cut the shell down to make a low nose geep 7 and applied paint and decals to make it look like the units in use on the real Twin Cities and Western Railroad.

TCWR 409 on the Willow Creek trestle on my Sioux Junction HO Scale Model Railroad.  The GP7 engine is by Atlas.  I cut the shell down to make a low nose geep 7 and applied paint and decals to make it look like the units in use on the real Twin Cities and Western Railroad.

TCWR 409 on the Willow Creek trestle on my Sioux Junction HO Scale Model Railroad. The GP7 engine is by Atlas. I cut the shell down to make a low nose geep 7 and applied paint and decals to make it look like the units in use on the real Twin Cities and Western Railroad.

 

Apr 212013
 
I removed the wheelsets in order to weather them and make sure they were in proper gauge.

I removed the wheelsets in order to weather them and make sure they were in proper gauge.

This Atlas GP7 is basically a unit built for Atlas by Kato in Japan.  It was probably built in the early or mid-1980s.  This predates DCC by many years, so special care is needed to install a DCC decoder in this engine.  Fortunately, Kato has made the job quite easy by the way the engine was originally manufactured.  Here’s how to install a Digitrax DH123 in one of these nice-running units:

I began by disassembling the trucks.  This step technically isn’t necessary for DCC installation, but I find it a good best practice for the running quality of the engine and appearance.  I made sure all wheelsets were properly in gauge (they were not) and painted the outside faces of each wheel with Polly-S roof brown.   This gives the appearance of a dirty, rusty wheel.  I reassembled the trucks and moved on.

I cut the power leads from each truck near the copper wire that runs along the top of the gray plastic board inside the engine.  I soldered the red wire to the engineers side wheels and the black wire to the fireman’s side wheels.  Then I soldered the gray and orange wires to the motor.  I later had to flip these around because I found the engine ran backwards.  No extra work is needed to isolate the motor here because the leads from the trucks now go through the decoder.  Unlike in Athearn and Proto2000 units, the frame in these GP7 units does not conduct electricity, so the motor is already isolated.

Installed on my Atlas GP7 with a Digitrax DH123 decoder.

Installed on my Atlas GP7 with a Digitrax DH123 decoder.

I then shortened the blue wire and split it into two wires, one for the rear headlight and one for the front.  I soldered in 1/4 watt 390ohm resistors to the yellow and white wires.  In series, I soldered in two Miniatronics 1.5 volt 30mA 1.2mm incandescent bulbs.  I still like incandescent bulbs in model railroad applications much better than LEDs.    Before doing so, I checked the length of the decoder wire to see that I didn’t have too much excess wire to interfere with the shell fitting over the mechanism.

All that soldered together, I inserted the bulbs into the headlight assemblies.   I secured them with globs of poster putty, which I consider to be God’s gift to us DCC installing model railroaders! Also, I secured all my solder joints with heat shrink tubing, which I also consider to be a great asset to the hobby!

I used poster putty on the front and rear headlight assemblies to ensure that the bulbs stay where they are supposed to be.

I used poster putty on the front and rear headlight assemblies to ensure that the bulbs stay where they are supposed to be.

I replaced the shell, but then realized that there was a glow coming from inside the shell.  This turned out to be the factory bulb on top of the Kato board, which had somehow survived being placed on DCC current without a resistor.  Not wanting the risk of it overheating nor its unsightly appearance, I removed it and replaced the shell one last time.

A test run on my layout revealed that the wheels needed cleaning (because of the earlier paint step, mostly), so I cleaned the wheels up with acetone, applied with a q-tip.  I have a DC powered wire brush at my bench to make the engine run while placed on a foam pad, wheels pointed up for easy cleaning.

The unit runs beautifully now and the lights look nice.

Mar 272013
 

DSC_4265Now that I am free of one big Progressive Rail project, I am free to pursue other interests in the hobby.  Tonight, I installed eye bolts (Details Associates) in the holes I drilled in the top of the long hood.   Places to drill were previously denoted by “bumps” that represented the eyebolts molded on the shell.   The older Japan-made Atlas/Kato GP7 had molded on grabs.  This is an example of such, so I shaved them off and drilled holes for Details Associates wire grab irons.

Stay tuned for a future post when I remove the 3M blue painters tape and reveal what colors this unit will be.

Mar 142013
 

Yes, I’ve been thinking about getting a nose job.   Those model railroaders reading this know that decent chop-nosed first generation EMD diesels are in short supply in the HO scale market.  The crux of the problem is that EMD built almost no  GP7 or GP9 locomotives with low short hoods.  DSC_4119 So modelers are left to fend for themselves or use out of date models that don’t look good or run particularly well.

So, I took my first shot at a chop nose this weekend.   I’ve got some body work left to do.   But I thought I’d give you a first look.  Here is my chopped Atlas GP7 in HO scale.  For the front of the cab, I just used the front of an Athearn GP38-2 cab.   I shaved the cab front off and filed it down to match the early EMD round roof contour.

Eventually, I want to build myself a pair of BN GP10 locomotives.  These will be non-dynamic shells, so this one is just practice.