Q: I’ve tried many methods to uncouple my rolling stock automatically rather than use a manual tool. Permanent magnets were far from satisfactory even when I devised a way to raise them at the appropriate time to a position closer to the couplers. I’ve modified an HOn3 electromagnet to fit between the rails, and this works when the couplers (Magne-Matic) are adjusted and aligned properly, but it’s not reliable either. The failure rate is about 50%. Is there a better way? Do most modelers just use a manual pick or tool? – Clint Lawrence
A: If you’re having N scale coupler problems trying to uncouple over a magnet, the trip pins might need adjustment. Your comment that you had to raise them closer to the couplers reinforces this assumption. Get an N scale coupler height gauge and check that all your couplers are mounted at the right height. Couplers that don’t match up can bind. You can add thin fiber washers to the cars’ trucks to raise the body if the couplers need to be higher. Hand-cut paper or styrene shims between the draft-gear boxes and the underbody can lower the coupler if needed.
Once you’re confident the couplers are all at the correct height, check the trip pins. The bottom of an N scale coupler’s trip pin should be .010” above the railhead. Micro-Trains sells a gauge to test this, but it’s basically just a sliver of sheet metal. A piece of .010” sheet brass would do the job just as well. If you find any of the pins are too high or too low, adjust them with a coupler trip pin plier. Micro-Mark sells one for N scale.
While you’re at it, make sure your couplers pivot and open freely. Heavily applied weathering can give your N scale coupler problems. Replace any couplers that stick. And if you can afford it, pick one brand of coupler to standardize on and replace any oddballs. Couplers work better when linking up with others of the same kind.
While these steps may not eliminate all your N scale coupler problems, they certainly can’t hurt. If you continue to have problems with your magnetic uncoupling performance, you may have to resort to manual uncoupling.
A lot of N scale modelers rely on manual uncoupling because of the same problems you lament. But this method has its advantages – specifically, the ability to uncouple cars anywhere on the layout, not just where magnets are installed.
And it’s cheaper than magnets! You can buy commercial uncoupling picks, but many modelers uncouple their N scale rolling stock by twirling the point of an inexpensive bamboo kitchen skewer between the knuckles. A thin dowel sharpened in a pencil sharpener would do the same job. Model Railroader’s former “N Scale Insight” columnist Jim Kelly wrote in our January 2015 issue about uncoupling with plastic swizzle sticks salvaged from cocktails.
Relying on the old 0-5-0 to handle your N scale car uncoupling may not be the most realistic thing, but it might be more reliable than remote uncoupling with magnets.
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