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Introduction to common N-Scale Couplers


Luckily, there are far fewer coupler choices when it comes to N-Scale (compared to HO/OO), this however still leaves a lot of modelers confused as to Confused about all the different coupler types available for N-Scale?

I want to start by saying that for many years I was not too bothered over the issue surrounding couplers as my collection was pretty much limited to a handfull of prisitne Fleishmann, Marklin, MiniTrix, Arnold/Rivarossi, Roco models, each pulling their own sets of favorite rolling stock. Then around 1999, I slowly started to add Bachmann, Hornby, Farish, Atlas, Cato, Model Power, Walthers and others to my collection, and thus started my frustration..

If you stick to a single manufacturers products, you probably may wonder what all the fuss is about, for the rest, this Article is intended to help make informed decisions about which coupler is best for your N-Scale collection.

Let me also add, that if you, like me always tend to pair certain locomotives with certain sets of rolling stock, you probably will end up compromising rather than trying to convert all your stock to a single coupler design.

In a nutshell:

There are two common types of N-Scale couplers that are widely in use:

  • Rapido (sometimes refered to as a “universal” coupler)
  • Knuckle

And, for those that model the European railways and/or have a substantial Fleishmann investment, the preferred choice is:

  • Profi-Coupler

However,  there are at least 5 different “N” Coupler types that you may run into, with each system having its followers, with both advantages and dis-advantages, these include:

  • Rapido
  • Knucle
  • Micro-Trains® brand couplers
  • Profi-Coupler
  • Accumate Coupler System
  • McHenry operating knuckle couplers
  • and a variety of brands of non-operating dummy couplers

What’s my recommendation ?

  • Remember there is NO Right or Wrong, and it ultimately comes down to availability, reliability personal likes and cost.There are thousands of modelers who compromise by using various couplers (because they do not want to spend extra money on changing couplers), and there are other modelers (“runners”) who do not spend a lot of time switching cars in the yard, so have no need to standardize couplers.
  • Depending on the size of your collection, you probably find a particular coupler is “dominant”, and there is nothing worng in sticking to this type.
  • If you want to standardize, you can’t go wrong with the  Micro-Trains couplers
    (however these couplers can be quite expensive)

For many people the choice will ultimately  be determined by the following choices:

  • You probably just want a dependable coupler System that will allow you to run trains reliably
  • For some people, the appearance of a real coupler is the most important consideration
  • Must work with as many
  • Club layouts probably will require compatibility with a specific type (i.e the Micro-Trains® brand knuckle)
  • Many people ultimately make a decision around affordability and argue the necessity of spending thousands to change couplers just for the sake of “standardization”


HISTORY :  Let’s Analyse what’s (is/has been) available

The very first N-Scale models were designed to be nothing more than toys so it should be no surprise that they came to market with a very crude “hook and loop” coupler.  The originator of N-Scale, the ARNOLD/RAPIDO company quickly found out that these couplers just wouldn’t suffice so they quickly developed a new coupler which they dubbed the Rapido coupler. The Rapido coupler loosely resembles a square with one side cut out.

While it may not look anything like a coupler on a real train, the Rapido Coupler has remained in use virtually unchanged for the last three decades.  This speaks for itself in regards to it’s reliability.

The Rapido coupler is still in use today although it’s days are numbered as most manufacturers are now offering knuckle couplers as standard equipment.  Perhaps the best thing that ARNOLD-RAPIDO did was to allow any N-Scale manufacturer that wanted to use the Rapido coupler on their equipment to do so freely.  This was a very smart move on their part since it quickly standardized things and allowed equipment from different manufacturers to work together.  If not for this single gesture on the part of ARNOLD-RAPIDO, N-Scale may not have gotten as far as it has today.



 Rapido Coupler Open coupler_rapido1
It may not look anything like a coupler on a real train but it has been a reliable standard for over 30 years.


The Rise of the Knuckle Coupler

Although the Rapido coupler was working well, in 1972 the KADEE company, which is known today as MICRO-TRAINS, introduced their first boxcars with a new knuckle style coupler that not only looked more like the couplers on real trains, it also acted like them!  The KADEE coupler, as it was called back then, was able to uncouple magnetically and then re-engage without locking to allow the car it just uncoupled from to be pushed into a siding.  This is known as pre-coupling and for the first time it allowed prototype switching (or shunting as it’s known it Europe) moves to be executed flawlessly without the operator having to use his or her hands at all!  As you might imagine the N-Scale modeling world was very enthusiastic over this new coupler however, KADEE decided not to offer their new system to other manufacturers.  The only place to get it was from KADEE and as a result it didn’t catch on as fast as the Rapido coupler did.  Also, while the prices of the KADEE (MICRO-TRAINS) products were reasonable, many model railroaders stayed away from the new system because the costs and time involved to convert all of their existing equipment could be very high depending on how much they had already acquired.

 MICRO-TRAINS Coupler Open MICRO-TRAINS Coupler Closed
The original and still the King of all of the knuckle couplers features magnetically operated uncoupling.


So how exactly does a magnetically controlled coupler work?  It’s quite simple actually.  Each coupler has small metal rod is inserted into it.  This rod is commonly referred to as the “trip pin” since it’s primary job is to “trip” the uncoupling mechanism into action.  The “trip pin” is curved upward and does a reasonable job of simulating the brake hoses on a real train.  Getting back to our model couplers, the train is coupled together normally and then taken to a special spot on the layout where a magnet has been installed between the rails.  The two pieces of rolling stock that are to be uncoupled are positioned over the magnet and then train is completely stopped.  This lets the slack out of the train and the forces of the magnet push the two metal “trip pins” apart which allows the uncoupling to take place.

In all fairness we should mention that most hobbyists don’t actually use the uncoupling magnets.  In many cases they work a little too well and provide a lot of unwanted uncoupling or “breakaways” as they are known.  This can be prevented by using electro magnets however, it seems that most hobbyists are quite satisfied uncoupling by hand or using a small screwdriver.  The advantage here being you can uncouple anywhere on the layout and not just where the magnets are.  In spite of the preference for not taking advantage of the magnetic uncoupling ability of MICRO-TRAINS couplers, they became the undisputed King of the knuckle coupler because they worked well, were easily obtainable and offered a large variety of solutions to convert almost all manufacturers of locomotives and rolling stock to their system.

Others Come On Board

In the early to mid 1990’s several N-Scale manufacturers, including KATO, PRECISION MASTERS (since acquired by RED CABOOSE) , INTERMOUNTAIN RAILWAY COMPANY and ROUNDHOUSE (Model Die Casting Co.) all offered versions of a knuckle style coupler.  Although all of these couplers could be coupled to the MICRO-TRAINS couplers and to each other with varying degrees of effort, none of them offered all of the advantages that MICRO-TRAINS did.  Hence, none of them ever became widely adopted enough to unseat MICRO-TRAINS as the standard coupler of choice among those modelers who preferred to use the knuckle style coupler.


 UNIMATE Coupler Closed  UNIMATE Coupler Open
Produced by PRECISION MASTERS and now owned by RED CABOOSE
It never really gained wide acceptance.


In the year 2000 ATLAS introduced their Accumate coupler which was a knuckle coupler that could be operated magnetically.  In 2001 KATO also introduced a magnetically operated coupler of their own which has received positive reviews. The KATO knuckle coupler is unique in that it doesn’t come with the “trip pins” installed thus allowing the modeler to make the decision whether or not they wish to use it’s magnetic capabilities or not.  Unfortunately, it is only available on KATO locomotives and rolling stock, not separately.  We understand that will eventually change.

 KATO Coupler Open  KATO Coupler Closed
A beautiful design that couplers very close and lets the modeler decide on whether it should work magnetically or not.


Let’s get back to the ATLAS Accumate coupler for a moment.  In 2002, in a somewhat surprising move INTERMOUNTAIN RAILWAY COMPANY abandoned their own knuckle coupler and adopted the ATLAS Accumate as their standard of choice.  That lasted a couple of years but now all INTERMOUNTAIN RAILWAY COMPANY models use the MICRO-TRAINS coupler as their standard of choice.  Also surprisingly, RED CABOOSE who you may remember purchased the tooling and rights to the PRECISION MASTERS knuckle coupler (a.k.a. the Unimate coupler) now offers most their products with MICRO-TRAINS as standard equipment.  Although ATLAS is offering most of their locomotives and rolling stock with Accumates, Rapido couplers are still included with most models and can be installed by the purchaser if they choose.

This coupler now seems to have been abandoned in favor of the MICRO-TRAINS couplers as standard choice.


In 2008 a new competitor arrived on the scene.  The McHenry coupler now comes standard on ATHEARN models.  It is extremely reliable and couples nicely with other brands of knuckle couplers.  Some have criticized it for the small spring that resides on one side but it is hardly visible under normal viewing angles.  Close-up photos such as ours shown below emphasize the spring more than normal.  At initial introduction the McHenry coupler is only available on ready-to-run ATHEARN models but some reports indicate it will be available as a stand alone product at a later time.

 McHenry Coupler Open McHenry Coupler Closed
The McHENRY coupler
Introduced in 2008 and initially only available on ATHEARN models now available as a stand alone product


Today’s N-Scale modeler has a lot of choices but the important point here is that the industry is now offering most equipment with knuckle style couplers and putting the Rapido coupler to rest.

The only exception to this are the European firms such as FLEISCHMANN, MINITRIX and ROCO who still offer the Rapido coupler as standard equipment with an option to upgrade to the FLEISCHMANN Profi-Coupler if desired.

 Accumate Coupler Open  Accumate Coupler Closed
ATLAS Accumate
This Coupler has gained wide acceptance and is now used as standard equipment on all ATLAS models.


A Coupler Just For European Trains


European modelers have a strong bias towards the FLEISCHMANN Profi-Coupler.

In German, the word “Profi” translates roughly to “Expert” and as such the FLEISCHMANN Profi-Coupler is designed with the more advanced modeler in mind.

It allows for pre-coupling just like the American knuckle style couplers do and it does couple the cars very closely however, this coupler is not a knuckle and it’s not very prototypical looking.  In fact, it really does not resemble any specific European prototype coupler that we are aware of.

The FLEISCHMANN Profi-Coupler does not work magnetically, it only works with an electrically operated coupler track which can be tricky to install on layouts that do not already use the FLEISCHMANN Profi-track system.

A big disadvantage to this coupler (for non European modellers) is the price.
They are not cheap and you have to buy them in bulk quantities.

Also, adapting some older European locomotives and stock can be very difficult.

 FLEISCHMANN Profi Coupler Open  FLEISCHMANN Profi Coupler Closed
The FLEISCHMANN Profi-Coupler.
While expensive and difficult to retrofit on older stock, it will couple your cars literally buffer to buffer.



Before we conclude, here’s one last trick.

If you are still not sure which coupler may be best for your needs you can try several of them out at once.

Simply make your own “conversion cars” by putting a Rapido coupler at one end and a knuckle at the other.

You can have some locomotives with Rapidos and some with knuckles and you can experiment with different systems until you decide which one works best for you.

We hope that we were able to demystify N-Scale couplers for you and have provided you with enough information to make an informed decision about which N-Scale coupler system may be right for you.

Of course, your choice ultimately depends on your own interests and the way you want to run your layout.

Each system has it’s own advantages and disadvantages.

Again, There is no right or wrong choice.

The most important issue is that You should be having fun running your trains (and that really is all that matters in the end, right?)

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