Coupler Conversion (PRR X26)
This is the stock model.
I started by removing the wheels from the trucks.
Next, remove the trucks from the frame. This is done by pulling on the bolster pins which hold the truck in place. These are not easy to remove. I used a pair of needle-nose pliers. Care must be taken not to damage the pins too much.
Micro-Trains made it very easy for us to convert these cars to body-mounted N or Z-scale couplers. Pre-drilled holes are already present as can be seen in this close-up photo. The left-most hole is for Z-scale couplers and the right-most hole is for N-scale couplers. (I had removed the underframe from the body for other work, but that is not necessary if all you are going to do is replace the couplers.)
It is a simple matter of inserting the coupler's supplied screw and, with a little determination, the new coupler is installed. The underbody is now finished.
The trucks need to be modified, as shown here, to be able to clear the body-mounted couplers. I used a knife to score a cutting line, and then snapped off the old coupler.
Adding Weight (PRR X26)
Removing the frame from the body of this box car is simple, once you know how to do it! The photo below shows me using a small flat-head screwdriver inserted in between the body and the frame. This widens the body away from the frame. With a little tug the frame will fall away from the body quite easily.
Here are the two parts separated. The frame is mostly made of metal, and it carries almost all of the weight of the model.
This car comes in at about 0.6oz which is about 0.35oz shy of the NMRA recommended practices for this three-inch model. A modeler recommended using lead shot, so I bought some at Bass Pro Shops for $15.00. I am not a hunter, but I suspect that any hunting supply store will carry this. This one bag will be enough to last me the rest of my life!
Because of the nature of this material, it needs to be constrained. I measured out about 3oz of the shot pellets and realized that I was going to need quite a few of them. The idea, then, was to build two boxes from styrene that sit right above the trucks. Since this is a box car, the interior was not fully visible, even with the doors open. One side of the car's frame had a hole in it big enough to loose one of the pellets, so a styrene piece needed to be glued over it to keep the shot in the box.
Plastic glue was all that I needed to assemble the boxes and to then attach them to top of the frame. I made the boxes small enough to clear the body of the box car.
And the boxes have been filled. Of course, the shot has to be glued in place. At first I tried white glue, thinking that since it is liquid enough to drain through all the shot, that they would be bonded together. However, after several hours of drying time, the pellets were still loose. I decided to use superglue. Several drops of that in each box made this one cohesive unit. The car could now be turned upside-down without loosing its "load".
Coupler Conversion (PRR X43a)
This is the stock model.
Converting the Micro-Trains PRR #603125 from the original N-scale, truck mounted couplers to the body-mounted Z-scale couplers are not too difficult. This page shows how I did it. Because surgery of the truck is required, I prefer to remove the wheels and then remove the truck from the frame. The first photo shows the truck removed from the frame. A small pair of pliers and a bit of force is needed to remove the bolster pins.
After disassembling the truck-mounted coupler, the bottom of the coupler box needs to be cut off from the truck so that it can clear the new body-mounted coupler. The orange line shows where to cut. Two passes with a sharp blade is all that is necessary. After that one can snap the old coupler portion off of the truck, much like one snaps styrene.
The result of the surgery is shown here. Clean-up of the truck part is not necessary because it is not visible.
There are two holes visible in the frame of the box car. One matches the N-scale coupler and the other the Z-scale coupler. Both are there for body-mounting. That was a nice surprise. The orange line points to the appropriate hole for body-mounting Z-scale couplers.
All the was left to do was to use the small screws that come with the couplers and install them. A considerable amount of downward force was needed to get the coupler to really tighten down. The coupler sits just a touch too high when checking with the Micro-Trains coupler height jig.