www.nscaleinfo.com

Rapido Couplers


When N scale model trains first appeared on the hobby scene in the late 1950's a new coupler was introduced for this scale. This coupler which we refer to as a "Rapido" style coupler is a spring-loaded,wedge-shaped,design that became the industry standard for N scale.


Rapido-Couplers



Rapido couplers are not used by many modelers, they are cumbersome and don't look anything like the real thing.

Did I mention that they are really ugly?

Why Use Knuckle Couplers?

If you run American equipment the answer is obvious: It looks like the real thing, only that it's a little larger than scale. Furthermore, the couplers work very reliably. There are a few other makes that will couple and uncouple automatically with the Micro-Trains couplers, Atlas and Intermountain working couplers to name the best. It seems, though, that the reliability suffers when the couplers are mixed.

Intermountain, Bachmann and Red Caboose, among others, also makes non-working couplers but they can only be used for fixed consists.

If you run European equipment knuckle couplers can be used as well. They are much smaller and much more reliable than the extremely large and ugly Rapido couplers.


Micro Trains Couplers - Introduction:


Shortly after this scale gained popularity, the Kadee Co. developed a more realistic knuckle coupler that could be opened by a magnet placed under the track. The Micro-Trains Line Co. was formed as a separate company from Kadee taking the N scale items in the product line, while Kadee focused on HO scale products. This magnetic knuckle coupler is now the industry standard N scale "upgrade" or premium coupler. The Micro-Trains coupler comes as original equipment on their own brand of rolling stock and can be purchased for after market N scale upgrade of your equipment. Other manufacturers including Accumate (used by Atlas) and Kato also make magnetic knuckle couplers that are compatible with the Micro-Trains coupler.


Micro Trains Truck and Coupler


Within the last few years, Bachmann, perhaps the largest manufacturer of entry level and mid level N scale equipment, has introduced a dummy knuckle coupler that is compatible with the existing magnetic knuckle couplers. This coupler, while not capable of being opened by the under track magnet, holds the coupling more reliably and is more realistic in appearance than the Rapido coupler. Bachmann is in the process of changing their N scale line over to these knuckle couplers by installing them on their locomotives and rolling stock, while including a pair of Rapido couplers in the package for modelers that still use that coupler style.


Bachmann, Intermountain and Red Caboose dummy knuckle couplers are available, very economically, in bulk packages for conversion of large numbers of rail cars. In my opinion though, these have very limited use, especially if you want to switch around your layout, as they are not easily uncoupled, and of course, can not be uncoupled automatically like the Micro Trains and similar couplers



Red Caboose Fixed Knuckle Couplers



If you have a large number of N scale items and are overwhelmed with the thought of converting your entire fleet of rail cars to knuckle couplers you might consider fitting some of your cars as "transition" cars, with a Rapido coupler on one end and a knuckle coupler on the other end. In many cases, locomotives are a bit more difficult to convert from Rapido to knuckle couplers, so the transition car can be placed behind a Rapido equipped locomotive while all the cars in the train have knuckle couplers.

Atlas developed the "Accumate" type of knuckle coupler complete with trucks that works on the same principle as the Micro Trains type. They come in various models including the 50 ton friction bearing and the 70 ton roller bearing types.


Atlas 50 Ton Friction Bearing Truck and Coupler


WHY USE MICRO-TRAINS KNUCKLE COUPLERS?


If you run American equipment the answer is obvious: It looks like the real thing, only that it's a little larger than scale. Furthermore, the couplers work very reliably. There are a few other makes that will couple and uncouple automatically with the Micro-Trains couplers, Atlas and Intermountain working couplers to name the best. It seems, though, that the reliability suffers when the couplers are mixed.


Intermountain, among others, also makes non-working couplers but they can only be used for fixed consists.


If you run European equipment Micro-Trains couplers can be used as well. They are much smaller and much more reliable than the extremely large and ugly Rapido couplers.


HOW THE MAGNE-MATIC SYSTEM WORKS


To Couple:

  • Simply nudge the cars together.



Knuckle Coupler Diagram

To Uncouple:

  • Stop the train with the coupler directly over the uncoupler. The knuckle coupler should open as the magnets will push the pins apart.

  • Back the train slightly to disengage the couplers magnetic force and to draw the couplers off center. Pull the train forward while the couplers are in a delayed position.

  • Re-approach and push the uncoupled car past the uncoupler to the desired location.

  • Withdraw, leaving the car in place. The couplers will return to normal operating position once past the uncoupler.


BODY-MOUNTING OR TRUCK-MOUNTING?

Micro-Trains cars are generally supplied with truck-mounted couplers. Truck-mounted couplers are fine for small-radius curves but if you try to back a long string of cars through crossovers and complex turnout areas, you may be in trouble. What happens is that because of the large forces needed to push many cars, the trucks are skewed relative to the track and the wheel flanges therefore tend to snag on any track misalignment, for instance crossing noses.

With body-mounted couplers this does not happen as the trucks are allowed to swivel freely. That's why you will have less derailments with body-mounted couplers. Of course you'll have to use larger track radii than you can using truck-mounted couplers. As my planned layout is to be set in the 1950-1955 era my locomotives and cars will be much shorter than today, so I opt for a minimum track radius of 500mm (19.7in). This way I can safely use body-mounted couplers.

This on the other hand means that I have to convert much of my rolling stock but this is not as large a disadvantage as it may first seem. Micro-Trains cars are easy to rebuild as the truck-mounted couplers can simply be cut off and new body-mounted couplers installed. I also swap the standard wheelsets for M-T's low-profile wheelsets. Other manufacturer's cars may be more bothersome to convert but as many non M-T cars are supplied with inferior couplers and trucks I'll fix that at the same time.



top_arrow