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Coupler Conversion

This page covers how to convert the AF-compatible couplers and wheels to the scale ones. All that is needed to do this is provided in the box, except that you need some tools. I used a small philips-head screw driver, a small pair of tweezers, and the NASG standards gauge to verify the gauge of the scale wheels.

(external link: NASG Gauge)

The large AF coupler is truck-mounted so that it can handle the very tight curves that typical AF-style layouts have. We are going to convert to the scale couplers, which are the prototypical body-mounted couplers. A philips style small screwdriver is needed to remove the truck from the body.

This is what you are left with. The large coupler is now obsolete. You must hang on to the screw to re-install the truck later on.

The first thing to do is to install the scale coupler. A shim plate is provided in the box, and I decided to use that. You can omit that if you think the coupler sits too low, but I found that it was a good match. There are three long screws in the bag. Those are the ones that you want to use for this coupler. I installed the center one first, and then installed the other screws. I waited with tightening them down until all three were ready to go. As I tightened them down, I kept checking the coupler head, to make sure that it kept moving freely. There is really no reason for overtightening these three screws, as they provide more than enough strength to pull any train.

The AF truck-mounted coupler has a built-in shim to have the body sit at the correct height. When you switch to the scale coupler, a new shim is provided that needs to be placed on the truck bolster.

The next step is to replace the wheels in the trucks. People have been reporting that this is very difficult to do. Apparently, the history on this issue was that earlier SHS designs for their freight car trucks made the spacing for the trucks a bit too wide, allowing the wheels to fall out quite easily. I have experienced that myself. It didn't happen during operation, but when picking up the car and then replacing that car's couplers or cleaning its wheels, it did happen a few times. So, apparently ScaleTrains had its factory tighten up the spacing a bit. The first one I did was indeed a bit of challenge, but I figured it out. What you have to do is to twist the truck such that one sideframe of the wheel is facing away from you and the other sideframe is facing toward you. The side that is toward you should be toward the bottom of the truck. You can then, usually, push the pointed-axle out of its cavity in the truck. A good bit of force is required. To install the scale wheels, you do the same thing, but in reverse. Insert the scale axle point into the cavity in the sideframe away from you, and then push the other end into that sideframe's cavity, all the while keeping the trucks as a whole, twisted. Again, a good bit of force is required. The second wheel/axle I did was much quicker, and then all of the remaining ones became near trivial. But, at least now we know that these wheels will not fall out for any reason.

What a difference scale (left) versus hi-rail makes. I found that the scale coupler sat at just the correct height with my coupler-height check gauge.