Here are some hints that applies to all model railroading scales that use Kadee® Magne-Matic® Knuckle Couplers. Many problems with couplers can be avoided if enough time is spent making sure the couplers are at the proper height, securely mounted, and fine tuned where needed. “Close enough” is not a good practice if you want reliable coupler performance.

All of your couplers need to be mounted at the same height using a coupler height gauge and be as level as possible with no droop or slant. Even if the coupler pocket (draft gear box) is level, the coupler itself may not fit into the box properly and droop or at least have some vertical play. Check all of your couplers with one of our coupler height gauges for the particular scale you are working with. Our Coupler Height Gauges will help you with proper coupler heights, trip pin heights, and other helpful features that are built in to the Coupler Height Gauges depending on the style of height gauge you chose to use. Some modelers have problems with trip pins hanging up in their trackwork. This, most often, indicates the coupler is not mounted correctly. It’s either mounted too low or it is drooping which drops the trip pin low enough to hang up it the trackwork. The trip pin is factory set and should not need to be adjusted if the coupler is mounted at the correct height. Before you adjust the trip pin always check the coupler height and mounting with a coupler height gauge making sure the coupler height is “correct” not just “close enough”. If you are mounting a coupler with a separate draft gear box, be sure the gearbox lid is oriented up so the lid can’t flex down during operation. If you are mounting the coupler in a cast on draft gear box, make sure the cover plate, or lid, does not flex down under during operation. Check the vertical play, couplers that move up and down too much will tend to want to slide out of each other. Too much play will cause lots of problems.

In our HO coupler line we have various offset couplers that help compensate for coupler heights that are too high or too low. Each offset is .050” higher or lower than the center set shank couplers such as the NO.5® or #148 coupler. Note: Shims may be required to correct coupler height if the next coupler offset is to great. Use the #211 coupler shims to lower the gearbox lowering the coupler height; Use the Red #208 or Gray #209 fiber washers between the trucks and underframe to raise the coupler height.

We do not have offset couplers in S or On3 scale, but we do in the O, #1 and G scale. Note: The coupler offset for each scale is the thickness of the shank for that particular scale of coupler.

Most of the popular On30 models are made to use HO Scale couplers like the (NO.5® or #148) mounted at the HO scale coupler height. However, there are many that use regular On3 couplers. Since On30 models run on HO gauge track you need to use our #205 or #206 HO Coupler Height Gauge when using HO size of coupler for On30 models or our #815 Coupler Height Gauge when using On3 #803 or #807 Couplers on On30 models.

All of our couplers, HOn3 through G scale, are Magne-Matic® and feature Delayed Magnetic Uncoupling® Action; Our couplers are designed to uncouple over an in the track magnetic uncoupler (when slack is applied over the uncoupler). However, they are also easy to uncouple with the #241 Dual Tool - Manual Uncoupling Tool.