American Model Supply knuckle couplers

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1:32 scale, working knuckle couplers
American Model Supply
33268 Central Avenue
Union City CA 94587
Price: $10/pair
Web site: www.amstrains.com

Working knuckle couplers and sprung draft-gear boxes for 1:32 scale

Pros: Prototypical, working drop pin; Kadee #1-scale #820/920 mounting-hole compatibility; perfect size for 1:20.3 cars using three-quarter-size couplers

Cons: Slightly oversize for 1:32 scale

American Model Supply (AMS-a division of Accucraft) has released a knuckle coupler for 1:32 scale. This same coupler is provided on their new 1:32 boxcars and second-generation reefers. This is a welcome product as, until now, the only options for readily available working scale couplers has been Kadee. Other couplers, such as JME, Aster, and Precision Scale, while representing the pinnacle of accuracy, are typically in short supply. With AMS’s new coupler, modelers now have two options in the reasonably priced coupler market.

AMS uses the same size draft-gear box and mounting holes that Kadee used for its #820 and #920 couplers, so AMS’s will retrofit without any modification to the model’s frame. The couplers also mount directly to MTH 1:32-scale cars, as MTH supplies their cars and engines Kadee-coupler ready. The #820/920 draft-gear box is oversize but allows the couplers to work on radii as small as four feet when body mounted. A smaller, correct-size draft-gear box, like Kadee’s #821/921 would also be a good option for the AMS couplers. The minimum radius would then be about six feet but much of the available Nº 1-scale equipment available today has a minimum radius of 10 feet anyway.

The couplers are mechanical and have working drop pins. The samples I reviewed worked fine, and the pin has a hole at the top through which a .031″ cut lever could be attached. The drop pin makes for a more realistic coupler, representing a full-size coupler, and is easier to uncouple by hand than Kadee’s. Coupling is a bit more involved because the coupler must be in the open position but that’s how full-size couplers work. On the whole, I liked the ease of use of the coupler, especially in switching operations.

Air hoses would need to be added to a car, something I never bother with using Kadees. In fact, the trip pins on Kadee’s couplers look more realistic (using the 10-foot rule) as a train goes by. Air hoses that aren’t connected don’t look right in a train, although they look great on a single display car.

My only criticism is that the AMS coupler is, overall, too large for 1:32 scale. It’s even larger than Kadee’s Nº 1-scale couplers, which are also slightly oversize. A type-E coupler (industry standard, introduced in 1932) is 1417/64″ wide. A survey of couplers on mid-20th-century locomotives and cars show two different size ranges: 133/8″ to 141/2″ (type-E size) and 163/8″ to 165/8″ (later AAR versions). The AMS coupler scales out at 1725/32″ wide, too large by about 25% or 7% (depending on the prototype chosen for comparison). I suspect it may have been designed for 1:20.3 scale. Railroads such as the Southern Pacific used 3/4-size couplers on their three-foot-gauge equipment. That would be about 103/4″ (101/8″ to 115/8″, as measured on SP narrow-gauge cars). The AMS coupler in 1:20.3 scale is 115/16″, within the range.

Overall, I do like this coupler, especially for operating railroads. I hope that AMS will come out with a smaller version, with draft-gear box, for 1:32 in the future.