Photos by Randy Lee
Because I model the Rio Grande/SP/UP Tennessee Pass line in Colorado, unit coal loads heading east, and similarly sized empty unit trains heading west, are a primary traffic source for my layout. With the introduction by Deluxe Innovations of the PSCX (Public Service Co. of Colorado) Coal porter cars, my opportunity to build a prototypical unit coal train for my layout had arrived. I operate Aztec Manufacturing track-cleaning cars, but at the time I was assembling my PSCX unit coal train, Aztec only made a track cleaner which fit into a 40' boxcar body. Although I had an Aztec 40' Micro-Trains MOW boxcar track-cleaning car, I wanted a track cleaner in a PSCX Coalporter that I could run in a unit train. It's a fairly simple kitbash, so let's get started.
First, take the shell off the Aztec Track Star, revealing the anodized aluminum roller housing to which the trucks are attached and into which the Cratex® abrasive roller fits. Remove the trucks and set them and the'roller aside, leaving the frame. If you want the car to operate on tighter radii, you must offset the roller to prevent it from dropping between the ralls. Using the Figure as your guide, remove 15/16" from one end of the roller housing. A milling machine makes this job a lot easier, but like most modelers, I don't have one. I convinced a friend of mine who does to do the cutting on one, but I was able to do one with the itemized hand tools with satisfactory results. If you use the hand tools, I suggest starting the cut with a razor saw, but using the hacksaw for the bulk of the cutting, since the anodized aluminum is quite hard.
Remove 1/8" from the top of the casting to make room for the coal load, and 1/16" from the bottom so the roller will sit in the proper position on the rail. Removal of this material can either be done with the razor saw and hacksaw or with the mill file. If you choose to use the file, you might want to first cut off the remaining truck-mounting stud.
Now we need to modify the Coal porter. Remove the trucks from the car and turn the carbody upside down. Using the razor saw, make a vertical cut through the two bottom tubs just inside of the vertical end of the tub wall that faces the car end. DON'T CUT ALL THE WAY THROUGH THE TUBS TO THE SIDESILLS. Stop your cut about 1/16" from the bottom of the side sills. Using the roller housing as a guide for positioning the second cut, again use the razor saw to cut to about 1/16" from the sidesills. The distance between these two cuts should be 1". Because these cuts aren't made deep enough to cut through the center beam between the tubs, you will need to use the point of the razor-saw blade to cut it. On all these cuts, take your time so that you do not mar the outside plastic of the carbody.
Once these cuts were done, I used the foam cutter to remove the plastic between the two cuts. My foam cutter, called a Wonder Cutter and purchased at Wal-Mart, comes with a very thin wire which fit easily into the slot left by the razor saw. Once turned on, it readily cut the plastic. Rather than try to make a final, smoothed cut with the foam cutter, I left some of the plastic on, then used the various files to smooth and straighten the opening to fit the roller housing. If you don't have a wire foam cutter (or using it to cut up a car is too intimidating), these lateral cuts could be made with a new #11 blade in an X-Acto knife. Using a metal straightedge to align your cut, lightly scribe your first cut, then carefully make repeated passes with the blade until your cut goes all the way through the plastic. The bottom of the housing should now fit through the hole in the tubs, but it may still sit up too high on the short end. If it does (as did mine), use the edge of the mill file to file a slot in the middle of the bottom edge of the short side cut. This filed slot will fit over the small, molded plastic clip which holds the end weight of the Coalporter in place. File only a bit of the edge off at a time, so that you gradually bring the casting down to a level position within the carbody. Now, insert the roller into the casting, and drop the housing into the carbody. If you left about a 1-16" of plastic below the bottom horizontal sill, that plastic should just touch the brass center of the roller, thus centering it. If you removed too much plastic, then shim the opening with Evergreen styrene to center the roller.
Micro-Trains 1035 trucks were substituted for those that came with the car. The coal load was filed to fit and placed over the top of the housing. It should fit snugly. I then tested the car, first alone behind an engine, and then at the head of a 50-car unit coal train. The car works well on curves as sharp as 10.5" (the sharpest I have). Aztec now offers 50' cleaner cars with the roller offset to accommodate sharp curves, so you may want to investigate using that housing as your starting point.