|Kadee couplers for European HO rolling stock
Author: Georg Helms
(EMail: [email protected])
If you want to do switching with somewhat realistic looking HO models
of European prototypes, without using tweezers to handle original
couplers, there is no way around Kadee couplers. But it does not look
really elegant to use simply the NEM pockets with the matching Kadee
versions: Instead, I install the Kadee couplers where they belong,
that is in the center of the buffer beam. So they are located higher
than according to US practice, and the modified models look like the
Swedish/Norwegian Kiruna-Narvik stock, for example, or like some
German experimental vehicles (see for example "Carstens, Güterwagen
Bd. 3, page 154, 2nd picture from above), or some British
stock, like some of EWS´ Class 66. Also, the present Z-AK, as used by
the DB on some freight stock, does not look that much different.To
make a long story short: Even if there are not many real prototypes,
the modified models look like "could-have-beens" to me.
For real buffer-to-buffer-operation, the same
conditions apply as described in the past for operating with original
couplers: To avoid buffer lock, the used radii, easement curves,
intermediate straights (between S-curves) and vehicle lengths need to
With 55cm (approx. 22") minimum radius, easement curves (15° of
80cm are sufficient!) and approx. 220mm max. vehicle length, things
are going pretty well. With longer vehicles, also steam locomotives
with leading/trailing axles (because of the long overhangs relative to
the guiding driving wheels), you can let the Kadee couplers simply
protrude further over the buffers, as these couplers - other than
original couplers - are also able to push! So, with these few
vehicles, you are not operating buffer-to-buffer, but you are able to
use them, and it does not look so bad at all: The couplers in the
center of the buffer beam are looking "logical", other than
those low hanging close couplers (which I only use for passenger
trains consisting of long eightwheelers, where you don´t see anything
between the cars, anyway).
Of course, I remove the NEM pockets; they were always annoying me, by
the way. The Kadee couplers are coupling exceptionally smoothly, as is
common knowledge, can be (delayed) uncoupled magnetically, and can not
only pull, but also push (see above!). If you ever pushed a train with
Kadee NEM couplers, you might have bad experiences: The reason is, in
my judgement, that that setup has too many joints, which is not the
case with my way of installation.
Below I will describe the various ways of installation, and what needs
to be observed to achieve really troublefree operation.
Vehicles with sprung buffers (preferred arrangement)
Here the long couplers No. 46 (resp.26 - same coupler, but more
hardware for different installation options, which are not required
here and make the 26s more expensiv than the 46s - but the 26 may be
easier to get) with the relatively easy to install coupler box and
spring of the "famous" US-standard type No. 5 are used. The
buffer beam must not be thicker than approx. 1mm, to let the coupler
protrude that much over the buffer faces, that the vehicles couple
without the buffers touching: Otherwise the coupling happens only with
some "violence" (to compress the buffer springs), and the
magnetical uncoupling not at all. Anyways, the coupler box needs to be
shortened to the length of the spring (deburr it if you use a saw or
use a knife - just watch your fingers, although blood washes off
nicely from plastic).
With thicker or in the center recessed buffer beams, the coupler No.36
comes handy: The coupler itself is the same as above, but the draft
gear is shorter and can be shortened further. But: No advantage
without disadvantage! The spring is a real bitch to install!
|The opening in the buffer beam should not be too tight: Wide enough
for the coupler shank to be pushed through, that is 5.5mm, and approx.
2mm high. Shallower is possible, but the coupler shank must not, under
no circumstances, touch or even hang in the opening, otherwise the
delayed uncoupling does not work (I learned that lesson the hard way:
From my first installations I had to rework some, and that means:
Taking out the coupler - this usually destroys the coupler box -
making the opening larger, new installation).
To provide space for the coupler box, it is convenient to cut a large
opening into the underframe after disassembly of the vehicle. By doing
this, also space for the sprung buffer stems is created. The
installation of sprung buffers had been described before. With scale
width underframes (like newer Fleischmann and also Roco) I enlarge the
space behind the buffer beam with a 2mm mill (in a power tool) to the
outside into the side sill (be careful - you might brake through!) to
prevent "cockeyed buffers"! I secure the buffers into the
buffer beam with rubber cement. Superglue has the tendency to creep
everywhere, also where you don´t want it, that is into the buffer,
and that was it for the springing action...
The coupler box can be adjusted and glued only after the coupler shank
has been pushed through the buffer beam. That means you have to handle
four parts at the same time. Therefore I glue, wherever possible, a
styrene plate (sometimes with some shimming) after assembly of the car
body to its underside resp. to the weight. Then it is relatively
simple, using liquid styrene glue, to adjust the coupler box properly.
During this process it may happen that glue creeps into the box and
the coupler moves "stickily": Don´t worry, just wait until
the glue is dry, then break the coupler loose, and everything is fine.
I consider the plastic glue as an adjustment aid only and use two
piece epoxy as the final glue (I don´t care how my operating
equipment looks from below).
The Swiss "Seetaler" coach with its low end platforms uses
couplers No. 21 with offset head ("underset shank"):
Although the actual height of the coupler head is not very critical,
in this specific case the offset was necessary.
Of course it is an alternative to open the buffer beam opening from
the underside and install a preassembled coupler unit without hassle
from the bottom of the vehicle: This may be recommended for the
beginning, but with the so far described couplers I somehow don´t
like it: Either closing the buffer beam again or leaving it open are
no altenatives for me - others might see it differently.
For the next version it is somehow different:
Vehicles with fixed buffers
Models with buffer types which are not available in sprung versions
(like rectangular high performance types), I do not install sprung
buffers. "Do it yourself" is too much bother (an
anti-rotation device would be something else to make up; the
Liliput-Bachmann rectangular type wobble like crazy...). A
"wrong" buffer type is no option for me, and leaving the
original buffer saves time and money.
Here I use the longitudinally sprung coupler No.4 (in tight spaces
also the No.15 with smaller box; see below). Buffer-to-buffer
operation is only possible when pushing the train though, but a train
with significant space between the buffers when being pulled does not
look so impossible - see my remarks in the beginning.
But cars with this type of couplers should only be pulled by really
smooth running locomotives (that is without longitudinal
irregularities), otherwise there is awfull jerking action in the
train! By the way, that is the reason why my Roco 290 (first series)
is only a dummy now, but that is another story.
The No.4 is usually installed from below into an
opening in the bufferbeam that matches the cross section of the box.
The coupler box needs to be shortened, deburred (very carefully!) and
rivetted together. If the front of the box is not exactly flush with
the bufferbeam, it is optically not very distracting. It is important
that everything is moving easily, "Greas‘em" helps a lot!
Before final fixing (you can temporarely use double sided tape for
trial runs) make sure the vehicles run through your tightest curve
without derailing: The No. 4 has less axial displacement than sprung
For final fixing I use two piece epoxy again. Don’t use real thin
epoxy to secure the cover of the coupler box: This creeps inside the
box and glues everything inside (yes, the hard way again...).
Wherever necessary, I fill up the buffer beam where it was cut out for
the coupler with styrene strip to its original thickness. A small
opening in the buffer beam and assembly of the coupler into a shorter
box "behind" the buffer beam is possible, but not advisable:
The short guided length of the coupler shank leads to such a high
friction, that delayed uncoupling is usually prevented.
|For vehicles with open underframes I prefer Kadee No. 15: The
coupler shank is the same as the No. 4, but the coupler box is much
narrower and can be shortened with a knife – but it is nearly
unglueable: To prevent small parts from flying all over the place
before final assembly into the vehicle (again with two piece epoxy), I
melt the two parts of the box together with a soldering iron (don’t
breath the stuff that is released during the process).
This preassembled unit can also be assembled through a proper opening
in the buffer beam in some cases.
Other examples are the Gützold Fas 126: Here the coupler box,
together with some styrene bits and pieces, replaces parts of the
original center sill!
Simplified approaches for groups of wagons
Groups of cars that shall not couple or uncouple automatically, can be
equipped with fixed couplers (uncouple o.k., but couple very rough) or
pivoted, but unsprung shanks (the relatively low priced No.5 with
extremely shortened coupler box which does not allow the usage of the
spring - if you don’t want it to stick out from the buffer beam,
which looks really ugly).
A word to the relatively old No. 16: This can of course be used, too,
but I don’t like it , because it gets shorter when rotated.
General hints for coupler adjustment:
Above I noted already that the coupler height is
not really critical. The coupler should sit in the height of the
buffers, maybe a bit lower. But you have to be careful on some older
Fleischmann and newer Märklin models, as their buffers sit way too
high - just check in advance! 12mm from rail top to buffer center is
correct (some prototypes deviate slightly).
Märklin eightwheelers, like the French/Belgian/Luxemburgian ore cars,
can be lowered (wow, how much better that looks!) relatively easily
after removal of the close coupling mechanism. On some Märklin
fourwheelers the buffers should be mounted lower than original (but
this only helps if the axleguards are not too much
"distorted"). The typical 0.5mm discrepancy of the newer
Fleischmann models is not critical.
The uncoupling wires of the Kadee couplers need to be bent downwards
for magnetic uncoupling per the instructions. Some wires needed to be
bent "outwards" at the lower end for proper function.
Some notes regarding the uncoupling magnets: The
strong under-the-rail magnet Kadee No. 308 also attracts steel axles,
which are the only ones available for European vehicles. If you
don’t like that (it’s no real problem for operation), use
electomagnets (expensive and not really pretty) or a hinge for the
308s (see the instructions).
In either case, mount the 308 as close as possible under the rail and
use the sheetmetal plate which is supplied with the magnet.
Now, have fun and a lot of patience! So far I converted some 150
vehicles. Difficult were only some locomotives, where I used a hacksaw
(really!) to provide the space for the coupler box in the zinc
underframe. I might invest in a power mill in my next life...
[ last updated 31st Dec 2003 ]