drawing courtesy of Athearn, Inc.
photo by Richard Schumacher
Webmaster’s note: This article was written a few years ago. While the article still contains valuable information on the assembly of basic HO scale car kits, Athearn (in 2010) has discontinued their “blue box” and MDC/Roundhouse kits (although many are still available in hobby shops, online, and from other modeler’s collections).
“Shake the box” kits have long offered good quality at reasonable prices. Although a number of manufacturers, including Life-Like Proto 2000, Intermountain, Kato and Red Caboose, now offer “upscale” (more expensive) plastic models, Athearn “blue box” kits still provide the best value, especially for the beginning modeler. Even with their recent price increases, MDC/Roundhouse, and especially Athearn, are still the mainstays of the model railroad market and the backbone of most of our fleets, and are so popular that hobby shops often have packaged Athearn kits into starter sets.
While fit and finish are important to us, a car that leaves its coupler on the right-of-way, or picks a switch during an open house or operating session, is more than just an embarrassment – it’s a major nuisance. Usually such a car either ends up in a “dead” pile or back in your fleet, its problems forgotten until the next time the car ends up in a consist and produces another headache. These “shake the box” kits can use some minor tweaking to improve their dependability and performance. The problems and headaches only multiply if your goal is to assemble as many car kits in as short a time span as possible. Remember, this is a hobby! Model railroading is fun! This is not a race or a production line! There is an old saying that “there is always time to do it right the second time.” In other words, take your time, do it right, and enjoy your hobby. Let’s get started.
If you don’t own an NMRA Standards gauge, now is the time to get one. You will also need a #11 X-acto knife, a needle-nose pliers, a small rule with one end marked in 64ths, a needle file set, a large flat file, at least one Kadee coupler height gauge (I use two), a coupler trip-pin pliers (unless you feel comfortable bending them with your needle-nose), #0 Phillips and 1/8″ straight blade screwdrivers, a good side-cutting pliers, some sort of tweezers, a variety of drill bits (and holder), a 10-32 tap, a postage or dietary scale, and your favorite weighting material (lead weights, sheet lead, etc.). You also need a variety of glues. I prefer Plastruct liquid cement, Pro-Weld, 3M silicone glue, Super Glue brand Thick Gel CA, and Zap-A-Gap CA+ by Pacer. You will also need a “shake the box” car kit. We will discuss Athearn as they represent the majority of my large stock of cars, and I have probably built well over 300 of their kits in the last five or six years.
Every car that I have ever encountered (including the fancier ones by the new guys) has needed molding flash cleaned off somewhere. Take your #11 knife and gently clean off any flash that you can find. Carefully check the underframe, the back side of sideframes, any place you can see a parting line. This is extremely important along the sides of the coupler boxes! Be careful not to remove the ears that the coupler covers clip over. Now, check the bottom edges of the car ends where the couplers protrude and clean any flash or excess paint. Cars that use a lower underframe need special attention, as they have little pins on the upper sides. The pins are what is left of the casting gates from the manufacturing process and can interfere with proper fit of the frame into the car body. Boxcar floors need to be shaved along their long edges. Boxcar doors usually have flash on the back side and inside the lower guide ears, as well as along lower edges. Check your other small parts as well, as they usually have some flash. And all cars generally have a little nib in the coupler box which is needed for proper operation of horn-hook couplers, but is unwanted when installing Kadees. Carve this nib out carefully. Handrails on tank cars should be adjusted for squareness, and all holes should be drilled through where ends of the handrails enter the carbody. This tips goes for Athearn engine handrails as well.
Have you noticed that there has been no mention of assembly? We’re not ready for that yet! Get the wheelsets out and examine them. Remove any little nibs from their back side, then roll the wheelset on something flat, like a glass tabletop. If they roll smoothly, install them in the sideframes and roll them on the flat surface again. If there is any indication of hop, check for flash on the wheel flange, and then test roll on a piece of track. If all checks out, move on to the other set. Athearn wheelsets are usually close to gauge, but most are also unacceptable for intense operation. The NMRA standards gauge is used to accurately check wheel gauge. I usually set my wheelsets to the widest possible setting, while still remaining within gauge. You must also check to see that the wheels are centered on their axles. This is where the small ruler comes in. If the wheels aren’t centered, they will climb rails, points, joints … anything they can. Next, let’s move on to the underframe bolsters. This is where I reduce wobble. Remember those horn-hook couplers you threw away? Get one out of the trash, check it for flash around the pivot hole, and placing the round pivot end over the bolster pivot, bottom it on the bolster pin. Take your #11 knife and carve off any of the bolster pin that is sticking out past the horn-hook. Do this to both ends.
Now we will mount the couplers in the box. Examine the Athearn retaining cover, making certain that it has been bent squarely and that the legs are equal. Put in the bronze centering spring and the coupler according to Kadee’s instructions and then place the Athearn cover over the retaining ears. Using the needlenose pliers, squeeze the cover tight to the frame on both sides of the coupler box. Do this for both ends. If you are dealing with one of Athearn’s quad or twin hoppers, you will probably need to clip a small amount off of the cover leading edge, as it interferes with the underframe and will not clip on correctly. I have also found that hopper car bolsters are not square and level, requiring some carving around the pivot to level the truck. If this is not done, when the truck is attached, it will tilt the truck, lifting the lead axle, causing the wheelset to ride up and derail on just about everything.
Place the trucks on a piece of track and place the frame over the trucks. Do not screw together yet! Put a Kadee height checker on the rails and push the frame toward it (this is where two height checkers come in handy – one on each side of the car). If the trip-pin hits the height checker, bend the trip-pin up until it clears, after checking to see that the coupler is at the correct height. If the coupler is low, Kadee has two thicknesses of fiber washers for placement between the truck and the frame (0.10″ and 0.16″ thickness). If the coupler is too high (doubtful, but possible), you will have to cut a shim for inside the coupler box, above the coupler. After coupler and trip-pin heights have been adjusted for both ends, weigh the entire car – couplers, trucks, body and all. Notice that I have not said to assemble anything yet! According to NMRA guidelines, cars should weigh one-half ounce per inch of car length, plus one ounce. On enclosed cars, I use automobile wheel weights to bring the weight up. On open cars I use sheet lead or “Heavyweights” from T&J Rail Services (strip lead in different thicknesses). Glue in the additional weight.
Now assemble the car. Glue parts, when possible, from the inside to reduce the chance of marring the finish of the car. Trim the shaft on the brake wheel in half so that the wheel fits close to the carbody. Tighten the truck screws until any wobble disappears, but allow them to pivot freely. Now set the new car in your yard, as it is finished.
Passenger cars need attention too. The Athearn streamline cars have a heavy coat of paint in their window openings that must be removed if you want the windows to fit. As with the other cars, remove all flash. Check and adjust all wheelsets. Use a razor saw to cut the windows into more manageable pieces. Use liquid cement from inside to carefully glue in the windows, taking advantage of capillary action to draw the glue into the joints. Glue sparingly! This goes for the heavyweight cars as well. Correct the weight of the cars, then move to the trucks. Using your side cutter, remove the talgo coupler tongue from each truck. For Athearn passenger cars, I use the complete #5 Kadee box and coupler. Making certain that the coupler clears the carbody, mark the location of the coupler box. Then drill and tap for 10-32 screws. I use nylon screws from Detail Associates. Dry assemble (no glue) the carbody to the frame and attach the coupler and trucks, then check the coupler and trip-pin height and adjust accordingly. If the coupler is too high, shim with styrene. If low, shim the truck or carve material from the floor of the car at the coupler mounting location. I know of no one that makes shims for the Athearn style passenger trucks, so you’re on your own.
MDC and Walthers cars are very similar and need many of the same adjustments. The most common trick is the bolster pivot pin trimming. Flash is very common, and cleaning this off adds to the look as well as the fit of the car. On MDC metal frame cars, the large file is a must, as well as the #11 knife and the needle files. I clean the underframes and file the clearances until the frame slides easily into the carbody, as painting the frame will close these gaps quickly.
I especially like the Walthers sprung trucks. Walthers provides them in a variety of styles and bearing configurations, but they require a little “tuning” work. Most difficult is the area where the bolster slides in the sideframe, in the spring area. Work this area with the #11 knife until the bolster slides smoothly, but do not damage the spring retaining pins. The springs are a little stiff, but you can play with them by clipping a turn at a time off of them with a small sidecutter. Kadee coupler springs also fit well.
I usually sit in front of the television with my wife, after my daughter goes to sleep, to assemble cars. It generally takes me about an hour to do an Athearn or plastic frame MDC, and about two to three hours for a metal MDC frame car, so I can usually get two a night into shape. The payoff comes when my trains run almost flawlessly on the Columbia Club’s modular layout for hours at a time.
Happy kit building!