Break-In Procedure
Break-in is a quick and easy but essential step in installing Prototype Couplers couplers. Doing so will result in couplers that operate smoothly and reliably as designed. Skipping this step is will almost certainly result in eventual frustration.
As supplied, the couplers have a rough surface texture. This is desirable from a cosmetic stand point for the body of the coupler but for the mating surfaces, not so much. The rough surface will prevent the couplers from sliding into and out of engagement as designed. The first step is to lubricate and the mating surfaces with graphite from an ordinary HB (#2) pencil. Powered graphite will also work, but it's hard to control where it goes and it's messy. Pencil lead is basically the same thing with a binder added to hold it together. This procedure will also color the wear surfaces of the coupler to emulate the wear that occurs on the prototype. The photo to the right shows the result more or less. The pencil lead is darker than what appears in the photo though. In fact, it will appear too dark at first, but will wear away in use. A harder pencil lead like 2H (#4) will lighten the initial color if desired.
The graphite should be applied all over the vertical face of the coupler head as well as the both the front and back of the knuckle. Pay special attention to the back of the knuckle at the parting line of the casting. Break off any flash there by drawing the pencil across the surface. A little graphite on the knuckle lever is not a bad idea either. Basically, just slather it up real good.
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Once the graphite is applied, the couplers should be operated by hand to allow the graphite to find its way into all the inner workings. The easiest way to do this is do turn the couplers upside down so they don't lock and then work them back and forth. This will also break loose any flash on the mechanism.
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It's also a good idea to rake the couplers over each other vertically to polish the surfaces and smooth away any potential operational problems. Turn the couplers right side up and let them lock together. Push them together while you slide them across each other vertically to polish the coupler head socket and front of the knuckles. You'll have to use a type E coupler to break-in the type F and H couplers since those couplers won't slide vertically. A little bit of a catch is ok as the knuckle parting lines cross. Now pull them apart with while performing the same action. This will polish inner side of the knuckle.
This video shows the whole operation and shows how a coupler pair that initially has some problems operates reliably after the break-in procedure.