DECODER INSTALLATION IN A WALTHERS USRA 0-8-0
This tutorial was published in the May/June 2008 issue of N Scale Magazine.
Recently, Walthers (Life-Like) released the much heralded USRA 0-8-0. This steamer has long been on many an N Scale steam aficionado's wish list. Older versions of the 0-8-0 suffered from poor running characteristics design and detailing that, in retrospect weren't great. Two of the 0-8-0's that come to mind were the Bachmann 0-8-0 and the Rivarossi 0-8-0. Each steamer had its own set of problems that continually plagued the loco.
The Walthers USRA 0-8-0 came with an impressive set of specs which include:
All-New Model * All Drivers Geared * Traction Tires for Superior Pulling Power * All-Wheel Electrical Pickup on Loco & Tender * DCC Ready - Socket In Tender * Railroad Specific Details * Accumate Knuckle Couplers * Flywheel Equipped For Smooth Operation * Constant Intensity & Directional Headlights * RP-25 Contour Wheels * Operate on Code 55 or Larger Rails * Heavy Die Cast Split Frame Chassis * Five Pole Skew-Wound Motor *
The only spec in question was the five pole motor, which in turn was actually a three pole motor. The three pole motor in reality is quite powerful and the USRA 0-8-0 performs extremely well at very low speeds.
The all wheel pickup on the steamer and tender enhance the performance of this steamer in switching situations. The traction tires come factory installed on the fourth driver. This loco comes with a spare driver if the modeler doesn't want to use the factory installed traction tire driver. This driver is easily changed by unscrewing the gear plate and dropping in the driver.
The operating Accumate couplers on both the front pilot of the steamer and rear of the tender are a nice feature and work well with Micro Trains couplers. The frame of this steamer is die cast and the loco has a good weight for its small size, however additional weight can be placed in the steamer and tender body without taking apart the entire loco.
The Walthers 0-8-0 comes packaged in a box similar to the offerings of LifeLikes 2-8-8-2 and 2-8-4 Berkshire. (See Photo 1)
Photo 1
The steam loco and tender are packaged in separate compartments in the box. The modeler join the tender and its draw bar to the loco using an accompanying screw and washer supplied with the steamer. When the 0-8-0 has to be stored, you can't leave the steamer and tender assembled. This is one of the drawbacks of this box setup. However, you can widen the steam loco compartment to store the completely assembled steamer and tender without too much difficulty. (Photo 2)
Photo 2
The Walthers USRA 0-8-0 is an extremely well detailed steamer. The detailing is comparable to the LifeLike 2-8-8-2 and 2-8-4 Berkshire. I rate this steamer in the high end of detailing when comparing N Scale steam locos. ( See Photos 3 & 4)
Photo 3
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There are however several problem areas with the Walthers 0-8-0. The first is the six pin connecting plug that connects the steam loco to the six pin receptacle in the tender. These wires are very delicate and fragile. The wiring can easily pull from the six pin plug during normal handling of the loco. One must be very careful when placing the plug in the tender's receptacle. Walthers charges a $15 service fee for any warranty repair work on this steamer. This might be a source of concern for the modeler as this plug is a definite weak point in the design of this steamer. Once a wire is dislodged from the six pin plug, its difficult to re solder the connection to the plug. (See Photo 5)
Photo 5
When test running this loco, I also came to the conclusion that some lead weight could be added to the steamer to improve its performance. Out of the box with a Lenz silver mini decoder installed, this 0-8-0 would pull about 12-15 cars (forty foot boxcars) on level track.
The ideal places to install weight in this small loco is between the cylinders near the gear plate, in the steam and sand domes of the boiler, beneath the windows in the cab and under the cab roof. (See Photo's 6 through 10) I used A-Line moldable lead weight in the steam and sand domes of the boiler. To remove the boiler shell, you must first remove the right and left ash pans under the cab. The boiler shell will then lift off with a slight amount of pressure. In between the cylinders, I used three small pieces of A-Line weight 1/16 inch thick. One piece of this weight was placed under the cab roof and two pieces of weight were placed under each cab window. This addition of weight to this loco was sufficient to improve the performance of this steamer initially by about 20%. Of course your results will vary depending on your layout and track work.
Photo 6
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Photo 10
With the boiler shell removed, you can get a birds eye view of the motor that drives the walthers 0-8-0. Yes indeed, it is a three pole motor and not a five pole motor as advertised. Walthers did revise there specs of the motor after this was discussed in depth on many railroad forums.. It is now listed as a three pole motor. In spite of having only three poles, this motor is still very powerful. At very slow speeds using DCC, I estimated that this steamer could travel at one MPH. This is quite impressive. (See Photo 11)
Photo 11
At this point in the installation, I decided to change the steamers Accumate couplers to Micro Trains Z scale #905 couplers. The JJJ&E has no level track on its 120' mainline, and I wanted to make sure that I'd have no surprise uncoupling of rolling stock on the long 2% grades of the layout. The MT Z scale # 905 coupler looks more prototypical for this steamer than the standard N scale Accumate coupler.
I lined up the Micro Trains Z scale # 905 coupler so that it sits in the middle of a Micro Trains N scale coupler when coupled to an adjacent car or loco. I had to place two shims for the coupler in the front pilot. This gave me an ideal alignment in regards to the N scale coupler on adjacent rolling stock. I used one styrene shim for the body mounted Z scale *905 coupler on the tender body. Once the shims were cemented in place with some CA cement, I cemented the Z scale couplers in position on the loco's front pilot and the tender body with a dab of CA cement. I measured the height of the couplers while the cement was setting to make sure that they were in the proper position in relation to an N scale coupler of an adjacent freight car. When the CA cement had completely set up, I tapped a hole in the styrene for the MT Scale # 905 mounting screw and fastened the couplers permanently. (See Photos 12 through 16) You can see how prototypical the Micro Trains Z scale #905 coupler looks when compared to the N scale Accumate coupler in Photo 15. The shims on the front pilot of the steamer and the back of the tender body can now be painted a stem loco black/grimy black. Use an 18/0 sable brush to paint the shims. keep the paint away the coupler mechanisms.
Photo 12
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Photo 16
Now for the decoder installation in the Walthers USRA 0-8-0 steam locomotive. The decoder for this steamer must be mounted in the tender. The light board in the tender contains an eight pin receptacle for the decoder. When you remove the tender shell from the frame (it just lifts off), you notice right a way there is little room for a decoder. Before I received this steamer, I envisioned putting a sound decoder and speaker in the tender. There is no room for both these components in the tender unless you completely remove the light board and accompanying weights located on the tender frame. I chose not to go down that path. If you want sound for this steamer, it would be easier to install a sound only decoder in an adjacent box car that has been modified with Kato tender trucks.
With present technology, placing a decoder and speaker in the tender can't be accomplished. Even with the removal of the upper weight that sits under the coal load, enough space for a decoder and speaker doesn't exist. (See Photo 17) You can see the factory installed eight pin plug in the light board. This is used for DC operation and must be removed for the decoder installation.
Photo 17
For this installation I chose a Lenz mini silver decoder. This is one of the smallest decoders in N scale. It is comparable to the Lenz mini gold decoder in function and features. However, The Lenz mini silver decoder costs 30% less than the Lenz mini gold decoder. The Lenz mini silver decoder supports the BEMF function. It's measurements are: L 0.43" x W 0.35" x H 0.11". The height of the decoder is a critical factor in dtermining its use for this installation. There is barely 0.15" of space available to position this decoder between the upper weight and light board below.
In contrast, Walthers suggests in its literature to use a Digitrax 143PS, which also has an eight pin plug. Besides the decoder being too large length wise, the height of the eight pin plug is also too large, preventing the tender shell from seating on the frame by a wide margin.
I adapted the Lenz silver mini decoder by adding a NMRA standard eight pin plug, soldering the seven wires of the decoder to the frame. Make sure you solder the correct wire to each pin of the plug. ( See Photo 18) The directions that come with the decoder tell you which wire goes to each pin on the plug. After soldering the wires in place on the plug, I covered the decoder with some Kapton tape to protect the decoder from coming into any contact with the metal of the weight above the decoder or the light board below the decoder. (See Photo 19)
Photo 18
Photo 19
Now remove the factory installed eight pin plug from the light board. Be careful when you lift it out so that you don't bend or break off the pins. The plug doesn't come out easily. (See Photo 20)
Photo 20
Now unscrew the top weight from the tender body. Be very careful not to strip the thread of this screw. It can happen. (Personal experience) Sometimes the screw doesn't come out easily. (See Photo 21)
Photo 21
Gently seat the Lenz mini silver decoder with the eight pin plug in the receptacle on the light board. Make sure that you line up the pins before seating the decoder on the light board. (See Photo 22)
Photo 22
Flatten out the wires on the light board gently with a flat blunt instrument before placing the upper weight back in position. Then screw the weight permanently in place. (See Photo 23)
Photo 23
I then added some A-Line moldable weight putty in the rectangular crevice on top of the upper weight. Shape the putty so it conforms to the rectangular outline in the weight.
In Photo 24 you see a closeup of the decoder and its relationship to the upper weight that has been screwed in position. You can see that space for this installation is at a premium. The tender shell should seat correctly if this is done properly. If the shell doesn't seat completely, trim away some of the moldable putty. You might also have to adjust the position of the upper lead weight. (See Photo 25)
Photo 24
Photo 25
A second way to install the decoder in the Walthers 0-8-0 is to use a decoder without the eight pin plug attachment.. In this case you must unscrew the light board from the base of the tender. Gently lift the light board up, taking care not to break the two soldered wires that go to the motor contact strips below the light board module.. It doesn't take much upwards pressure to break a solder connection. You can then hard wire the decoder wiring to the back of the printed light board circuit. This by passes the need for a decoder with an eight pin plug. Place some Kapton tape around the circuit board when the soldering is finished. The decoder is then mounted under the upper weight as in the first installation. Walthers briefly describes this method of decoder installation in an addendum that is supplied with the instructions. Make sure that you read all instructions that came with this steam locomotive.
Now I touched up all the parts that I added to the 0-8-0. I painted all the shims that I added for the Z scale couplers. I also painted the lead weights between the cylinders black. I painted the side rods and valve gear as well as the drivers with some Neolube # 2 blackening agent using a 18/0 sable brush. The tender trucks were weathered slightly with some Polly Scale Rail Tie brown. I installed two decoders in two Nickel plate 0-8-0 for this tutorial. (See Photos 26 through 29).
Photo 26
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Photo 29
The Walthers NMRA 0-8-0 on the upper level of the JJJ&E with working Micro Trains Z scale couplers, with a Lenz mini silver decoder installed in the tender, and judicious placement of additional weight in the steamer and tender. (See Photos 30 through 33)
Photo 30
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In conclusion, the Walthers USRA 0-8-0 steamer fills a void that has been present in N scale steam for many years. There are some problems to resolve in regards to adding additional weight in the loco and tender, but these are simple remedies to fix. The experienced modeler as well as the novice can make these changes without taking the locomotive apart. The decoder installation is relatively easy, provided that you choose the right decoder. One must realize the space requirements for the decoder which are miniscule to say the least.
This small steam locomotive will perform well if you temper your expectations. The Walthers USRA 0-8-0 won't pull 40 cars up a 6% grade. More reasonable expectations might be 15-17 cars after a significant break in time ( 8-10 hours) on level track. This locomotive is delicate and must be handled with extreme care.. With increased running time, this steamer will perform very well. The key is to run the loco and enjoy its performance. It is a wonderful small steam locomotive.
Stay cool and run steam......