The idea of a see-through car for inspecting trackwork is not new. In N- and HO-scale you can buy them from various companies. However, I thought it might be fun to make one myself. A car like this is great for seeing how the wheels behave when they go over turnouts. This is especially important if you hand-lay your own track and turnouts. I built one in N-scale and later on one in S-scale. I'll describe the S-scale version first, and the N-scale in the second half of this page. To be able to see how the wheels respond to the track, a see-through material is needed for this special "flat car". I decided to use some plexiglass that I had available. Using the table saw, I cut it to the typical dimensions of an S-scale 40-foot freight car (1-3/4 x 7-3/4 inches).
The other parts needed for the car are two trucks and a pair of couplers. The couplers are optional, but I have found that additional track problems can be discovered by coupling this car to another car and then pushing or pulling this inspection car through a turnout using the other car (i.e. not directly touching this inspection car). That is why I decided to add the couplers. I am using a pair of Kadee #808 S-scale couplers for this car. The trucks can be any representative truck and wheelset used on the layout. Same thing with the couplers. I decided to use the S-Helper Service's "PRR D2-F8 50 Ton" trucks with code 110 wheels (part #00047). These are heavy trucks that roll beautifully.
The trucks need to be mounted to the piece of plexiglass. Normal cars use a bolsters, but for this inspection car we don't need one. I found two bolts and matching nuts from the parts box and installed them onto the truck. The bolt needs to be long enough to allow the plexiglass to clear the wheels and then allow an additional nut to be placed on top of that. The two nuts are tightened against each other, which keeps them from moving up and down the bolt as the truck turns. Leave enough play to allow the truck to turn on the bolt.
Next, a hole needs to be drilled at both ends of the "car" to take the bolts. I marked a drill point in the center and 5 scale feet away from the end. I first drilled a very small pilot hole before drilling with the final drill bit. I made the hole just wide enough to clear the bolt's threads. If it is too wide, then the car will wobble too much. Using a knife I cleaned up the debris from the drilling.
The next photo shows a side profile of the installed truck. A nut at the top secures the truck to the plexiglass. And, we have ourselves an inspection car.
I then assembled the Kadee couplers and glued them to the plexiglass car using 5-minute epoxy. I don't have the right size tap otherwise I probably would have used the couplers' screws to install them. The glue works fine too, though. You can manipulate the trucks' bolts to get the body to be at the right height so that the couplers will match other cars on the layout. (Update: I found out that the coupler screws are actually self-tapping. The glue didn't hold the coupler boxes for but two weeks, so I drilled a hole and put the screws in place. It worked great.)
The next photo shows the completed car. Now it is time to start laying some track.
Another good use for this car is to verify that track is level. Make sure that the wheels are even or otherwise the car will always indicate not level track. This is a rather simple project to build, if you have the parts. For my old N-scale car I had to add weights to the center of the car to have it track reasonably well (see below). I am using a removable metal bar for weight for this S-scale version. That way it doesn't interfere with the see-through feature of the car, and the weight can be used for other purposes when needed.
For the N-scale version, the hardest part, in my mind at least, was how to mount the trucks to the see-through material. So I looked through my drawer that contains "stuff" that will never see the light of day on a layout, and found this old caboose from the Bachmann starter set. I removed the trucks and loosened the body from the frame.
My objective was to salvage the bolster pin area from the caboose's frame. The frame's metal weight was in the way, so I cut it with a razor saw. Eventually the frame became weak enough to snap off the end of the frame. Here is a photo of the frame cut up into several pieces. The remaining parts, of course, go right back into the parts bin. You never know when they come in handy.
Now that the demolition is complete, I needed to cut a piece of "Lucite" (clear plastic sheet, some sort of plexiglass). I bought this at Lowe's or Home Depot. An 8x10 sheet doesn't cost but a few dollars. Similar to the material I used above in the S-scale version. I took an average N-scale freight car and roughly measured it. Next, I cut a piece of this Lucite approximately 5/8" wide and 3" long. You can get fancy and make the sides perfectly smooth and round the corners, but this car is meant to be a tool, not to be run on the layout.
The next step was to attach the salvaged truck mounts to the plexiglass. Where on the sheet to place these was roughly determined from the sample freight car. Five-minute epoxy was used to glue them down.
I removed the trucks and metal wheels from a Micro-Trains car that I wouldn't run on my layout. These were attached with the screws from the caboose mentioned above.
Here is the car in action, clearly showing how the wheels behave as they roll through a turnout.
I lived with the car, un-weighted, for a while, but it just became too hard to keep it on the track. So, a variety of weights were added to get the car up to the NMRA spec of 0.95oz for this 3-inch car.
The last photo shows the car in action. It is still somewhat easy to see what the wheels are doing when they run over a turnout.