The Kato couplers come unassembled. They're cast plastic, five couplers per sprue, four sprues per pack.
| Assembly |
| Clockwise from right: a sprue with one set of parts removed, the two unassembled parts of a coupler, the assembled coupler, and a Kato truck (aka bogie) with the coupler pocket ready for installation. |
Assembling them requires no special skill or tools—an Xacto (or similar) knife or a sprue-cutter, at most—but a little bit of patience and a modicum of dexterity will go a long way. And maybe a bit of (double-sided) tape.
Once detached from the sprue, the two distinct pieces need to be pressed together to form a single whole unit. While you can build these on an as-needed basis, I find it better to sit down in a brightly-lit light-colored environment and just churn out a package or two of these at a time. The little halves do tend to spring away, even during the best of times, and finding the stray piece in poorly lit area is not what I would consider "fun".
One way you can make the assembly process faster is to grab a bit of tape to hold down one half of the coupler while you press the other part down onto it. Lining up those little pins that hold the two halves together is perhaps the trickiest part of the whole process. Once they're properly engaged with the opposite hole, the two halves squeeze together with a light press.
| Oops! || Properly Assembled |
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|Careful... when pressing the two parts together, the neck portions must be parallel. This coupler won't work, but is easy enough to fix: a gentle twist to bring the two parts of the knuckle together will do the trick. ||When properly assembled, there should be no gap between the two pieces; here, the inboard end of the coupler (the part that sits in the coupler pocket) looks like one single piece. |
The exact means by which by which you'd need to change couplers depends on the manufacturer, and the particular bit of rolling stock. In fact, I have one car from a later manufacturing run than its brethren, and between runs, they changed how the coupler is fastened...
In short, variety abounds. Here are a few ways I've done the exchange. There likely are many more. After doing a few, you get comfortable doing it, and can tackle other ways without much trouble.
Installation, Variant 1...
Frequently, you'll need to remove the truck (or bogie to the UK-derived) from the car. Most rolling stock fastens them by means of a small screw, but the Kato Series 50 passenger car trucks shown here use a pair of spring-loaded notches to hold the truck on an immovable post.
| Removing the Truck |
| For truck-mounted couplers (common for Kato and Tomix) you'll either have to remove a small screw, or pop the truck off of a flared post, like we do here. |
With these, you have to carefully, gently, press the little arm back while lifting the truck enough so the notch clears the crest of the post. An Xacto blade or very small flat-head screwdriver can help with this. Avoid forcing this, because breaking the truck is not a good thing. (Having removable trucks in the way that this breakage offers is a level of prototypical operation few are interested in producing.)
With the truck removed, we can see a cage molded onto the outboard end which holds the coupler, kept in place with a small metal spring.
Holding the truck right-side up, a gentle 90-degree twist of the coupler along its axis pops it out of the cage. Do this over a small container to catch the spring if you're inclined to reinstall it, because it can just fall out at this point.
Next up: the same in reverse, using the Kato coupler. Press it into the pocket 90 degrees from normal position, then twist it into place. There's no obvious indication of which is up or down, so it's possible to install the thing upside-down. This will not result in happiness. ;-] Make sure the coupler knuckle is "right-handed." To understand what that means, curl your right hand like a coupler: your fingers almost brought to a fist, and your thumb sticking to the left. When the truck is held right-side-up, the coupler should look like your hand. (This, by the way, is the same orientation as other knuckle couplers.)
| Not Quite There || That's It! |
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Once the coupler is in place, give it a test to make sure it stays relatively centered. In my case, this happens without the need of a spring, but if your coupler pocket is larger, it may need the pressure to keep it in line. Also, take a moment to verify the coupler really is installed "right-handed."
Passing inspections, the truck can be reinstalled: either by a gentle press onto the post, or by the screw, depending on the car.
Installation, Variant 2
In the case of my Tomix KoKi container cars, the couplers are held in place by a small sheet of metal with flanges on the side to hook into the coupler box walls. An Xacto or similar knife, or a very small flat-head screwdriver, pressed down between the plate and the coupler box will typically do the trick.
| Popping Off the Cover || Catch Disengaged |
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|Press gently, to just loosen the catch. ||Almost off. I do this in two steps. Less damage that way. |
With the cover off, the Arnold coupler can be lifted out. If you're so inclined, restrain the string (say, a bit of tape) so it stays in place. Then it's just a matter of dropping the Kato coupler in... but remember the orientation.
In this case, I was able to leave the truck on the body because the cover plate was exposed from below. Because the car is upside-down, I have to install the coupler "left-handed" so that when I turn it right-side-up again, it will be "right handed." Take a moment to check the coupler is in right.
| The Arnold Mechanism || The Kato Mechanism |
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|Here's what the coupler and spring arrangement looks like before. ||In this case, I kept the spring in. This seems to be optional (so far.) Note: upside-down truck, so left-handed coupler. |
Now, another moment needing finesse: putting the cover plate without the coupler (and spring, if present) falling out. If you use tape to restrain things, be sure that it is (or can be) removed. The adhesive will literally gum up the works if left in.
After doing a few of these, you can build up a nice cadence, and get through your collection in fairly short order.
If you're so inclined, you may leave one or two cars as "hybrids" with different couplers on each end. For example, if your consist remains intact, but changes engines periodically, you may put an operable coupler on the front of the head-end car. If running out and return, the rearmost coupler may also be operable.
...Or blocks of cars may have operable couplers every few cars, to allow cuts of cars to be switched without the expense of operable couplers everywhere.
...Or you may go to meets where they still use Arnold or other style of coupler; this car would allow you to couple to other peoples' equipment without fuss.
For me, for now, I'm just going with these Kato couplers because they work just as well as, and look better than Arnolds, without breaking the bank.