Narrow Gauge and Short Line Gazette logo Mar/Apr 2022
Volume 48, No. 1

Feature

A Locomotive Test Track Doing It In Style

By Craig Symington, MMR / photos by the author

One of the aspects of this hobby that I really enjoy is the challenge of reworking brass locomotives. However, after rebuilding the drivetrains and adding DCC, I’ve never had a very good way of test running these locomotives. The best I’ve been able to come up with is a jumble of wires and a length of flex track that I temporarily set up on my workbench or coffee table. For the longest time, I’ve wanted to build a proper test track.After years of struggling with this less than adequate setup, I developed a list of criteria that any future test track would need to meet:

This is how my workbench looks with the test track installed under my cabinets and shelf. You can see the white test track in the middle of the photo with two locomotives on it. It turned out to be unobtrusive as planned. For now, I have the junction box sitting on my workbench. In the future I may mount it under the workbench or under the test track to get it out of the way. For now, I’m not sure what will work best. What I am sure about is how pleased I am with this system and how well it works. It’s been a complete success.

1.When I’m rebuilding a brass locomotive, one of the first steps I take is to make sure that the drivetrain runs smoothly. Often, I’ll upgrade the motor and sometimes I’ll replace the gearbox. Once this is done, I will use a DC power pack to ensure that the mechanism is running smoothly. My new test track was going to have to support DC operation.

2.When there is a bind in the mechanism or I’m trying to find a short, I will place the locomotive in a foam cradle upside down with test leads clipped to the model. Using another test lead, I will probe possible problem areas to find shorts. My new setup was going to need the ability to support test leads.

3.Once the locomotive that I’m working on runs well under DC power, I’ll install a DCC Decoder. I then re-test the locomotive performance to ensure the DCC Decoder and locomotive are working at peak performance. Having the ability to run the model under DCC power was going to be a must for this new test track.

4.I use a dedicated NCE Power Cab, NCE USB interface, JMRI and my computer to program Decoders. The new test track was going to need to support these devices without having a jumble of wires all over my workbench.

5.Test running on a three-foot length of flextrack never seems to be long enough, but there isn’t enough room on my workbench for anything longer. The new test track was going to have to be at least two lengths of flextrack long and not clutter my workbench. Preferably, it would also have a curve in it to test for shorts as the wheelsets slide from one side to another.

I wasn’t sure how I was going to meet these objectives until I saw a Facebook posting from a fellow modeler. He built a test track on legs that floated above his workbench like a skinny table. With this setup, he still had much of his workbench free for working on engines. This gave me an idea. Above my workbench are cupboards. I realized that I could take this raised test track idea and flip it upside down. My new test track would hang under the cupboards!

I wanted my test track to be pleasing and strong, so I decided to build it out of pine. The roadbed was made from laminated strips of pine like the roadbed I created for my Telluride branch (May/June 2014 Gazette). I made pine blocks for hanging the roadbed from the cupboards. Along the back of the test track, I added strips of Masonite so that a derailed locomotive couldn’t fall off the back and come crashing down on my workbench.

I test fit my test track in place prior to painting. Once I was satisfied with the fit, I painted everything with white paint. As much as I write about HOn3 modeling, I also have a sizable collection of Canadian Prototype steam engines that I enjoy working on. Because of that, I installed HO cork and HO/HOn3 Micro Engineering flextrack on my test track. This would allow me to enjoy both facets of the hobby.

To solve the “jumble of wires” issue, and the fact that some of the NCE components were simply electronic boards that need electrical short pro-tection, I designed a junction box to house the components and provide simple plugs for connecting the wires. Through this box, I would plug in the NCE throttle and DC power pack. The box would also have outputs for the test track and test leads to clip to a locomotive. Following an internet tip from Phil Floyd, I also added a Decoder who’s grey and orange motor wires could be set as an output to run a non-DCC equipped (DC) locomotive using the NCE DCC controller. After sketching a wiring diagram, I ordered all the non-DCC components from Digi-Key.

Please follow along with the accom-panying photos as I walk you through this project and provide more details. In the end, my junction box is slick and met all my requirements. The test track is unobtrusive and works well. The whole setup far exceeded my expectations and I’m really pleased with the results. It’s made working on, and programing locomotives a lot easier. I hope my experience inspires you to create your own test track.

This jumble of wires is what I have been using for the past few years to test locomotives running under DCC. In the mess, is a USB board for connecting the NCE Power Cab to my computer for using JMRI Decoder Pro to program locomotives. The NCE components have un-protected circuit boards, and it was a matter of time before a stray wire shorted something out and destroyed the components. The single piece of flextrack was never long enough and would slide around on my workbench as the wires pulled on it. This mess was the inspiration for this project.
I added masking tape to the outside of the junction box and planned where all the components would go. I wanted the component placement to make sense from a flow standpoint. All the inputs and controls are on the front of the box and all the outputs are on the back of the box. This also allowed for a logical and organized flow of the wires inside the box. I used various drill bits and a utility knife to cut out the openings.
The front of the junction box has plugs for all the inputs, and controls what is output.
From left to right:
There is a 3.5mm input to plug in a basic DC power supply.
The rotary switch selects the three output options. The first option is power from the DC power pack input. The center option is motor power from the TCS T1. Finally, there is a straight DCC track power option.
The NCE faceplate is next. The NCE Power Cab needs to be plugged into the right plug for the system to work. The red LED will be on to indicate there are no shorts and the DCC Power Cab is working properly.
The USB port is for plugging in the cable supplied with the NCE USB board into my computer. This is used to program locomotives with JMRI Decoder Pro.
The back of the junction box has the DCC 120 VAC Power In on the right. It is for plugging in the supplied AC power adapter that comes with the NCE Power Cab.
On the left, there are two identical 3.5mm outputs. One output will go to my test track, while the other can be used to plug in a second set of test leads for working on locomotives in a foam cradle.
I test fit all the components in the box. The NCE USB board was mounted using stand-offs screwed to the bottom of the box.
Wiring diagram for the junction box.
This view shows the completed wiring inside the junction box. Looking from left to right across the back of the box (top of photo): The plug with the red/black wires is the power adaptor input for the NCE system and connects with the NCE faceplate. The two connectors on the right are 3.5mm female adaptors to create a pair of power outputs. These outputs connect to the center posts of the rotary switch which allow me to select the output from DC, the Decoder and straight DCC.
In the center/left is a TCS T1 Decoder. The black and red wires are connected to the track power outputs of the NCE faceplate. The orange and gray wires are connected as one input on the rotary switch. I programmed the Decoder to address “3333” since I’d never have a loco of that number, and then locked the Decoder from being accidentally reprogrammed. Selecting loco 3333 on the NCE throttle allows me to run a DC locomotive on the test track using the DCC throttle. I chose the TCS T1 Decoder because it has a high amperage output (1.3A) and should be fine with any HO or HOn3 DC locomotive, including those with open frame motors. This setup has worked so well, that I may never need to use a DC power pack with my test track.
Looking from left to right across the front of the box (bottom of photo): There is a female plug used for a DC input from a DC power supply. This is wired directly to the rotary switch beside it. The rotary switch is used to control the power to the two output sockets. The options are DC power, DCC Decoder power or straight DCC track power. Next, the NCE faceplate takes its power from the power adapter input from the back of the box, and sends a DCC signal to the Decoder and straight to the rotary switch. The last component is the NCE USB adaptor board. The USB board’s supplied coiled wire is stuffed in the box and plugged into the back of the NCE faceplate.
I didn’t want to modify any of the NCE components and simply wanted to use them as the manufacturer designed them. A 120VAC power adapter is plugged into the NCE faceplate to provide power to the throttle and track. With the faceplate’s connector inside the box, this connector became inaccessible. However, I found a female plug for the outside of the box that the NCE power adapter would plug into and soldered it to a wire with a male connector that would plug into the faceplate. This adaptor created a seamless transfer of power from the outside of the box to the faceplate without modifying any of the components. If I were to build this again, I’d add a toggle switch to the outside of the box and in-line with this wire so I could turn off the power without unplugging the NCE power adapter.
Because there is a seemingly endless range of options for 3.5mm audio cables, I decided to set that as my standard for feed wires. I think that the options for coiled wires, different lengths and even retractable wires, will give me plenty of choices for customizing my setup in the future. These types of wires are readily available at almost any retail store. The downside of this choice is that these are a 3-conductor cable and I only need two conductors. The other downside is that one of the conductors is sometimes a braided shielding on the wire. That was the case for the wires I bought, so I simply combined the right and left stereo conductors to be treated as a single conductor and used the braided wire as the second conductor. The braided conductor with the wires I bought needed to be twisted into a wire and covered with heat shrink tubing. The wire in this photo is my power output used for a locomotive in a test cradle.
If you are in a larger scale, you will want to pick a different wire standard with larger gauge wire to handle higher current draws. This small wire has sufficient capacity for HO scale or smaller.
This is the power input for my DC power supply. I added spade connectors so that this wire could be used on the screw terminals for any DC power supply.
Laminating layers of 1/8-inch thick pine strips worked so well with my Telluride Extension (May/June 2014 GAZETTE), that I thought it would work well for creating a test track. I added a 24-inch radius curve since that’s the minimum on my HOn3 layout. In this photo I’m gluing the strips together. Luckily my dad has a fully equipped wood shop and LOTS of clamps! The curved piece of wood on the workbench is a tool I made for checking track radiuses while I was building my layout.
The wood working portion of my test track is completed here. I’ve added Masonite guard rails along the back as well as pine brackets for hanging the track from the underside of my cabinets. Stop blocks were added at the ends of the track too. Eventually, I ended up painting the test track white.
I painted the test track white so that it would be visually appealing and make it easier to see. I added HO cork for roadbed and Micro Engineering HO/HOn3 code 55 FlexTrak. Eventually, I’ll add foam cushions to the front of the stop blocks to protect the pilots of run-away locomotives.
I used screws to attach the test track under my cabinets. In this photo, I have an HO Canadian Pacific 0-8-0 as well as an HOn3 D&RGW 2-8-0 demonstrating the flexibility of this dual gauge track system.
To program locomotives I simply use the USB port to plug my computer in. On my computer I’m running JMRI Decoder Pro and can see the immediate results of changing the Decoder settings by testing the locomotive on the test track. The NCE Power Cab and my custom junction box provide all the intermediate power and connections.

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