| DC-type Wagons on Märklin-Layouts? |
Let’s be honest - whom of us AClers (=Märklin-users) has never had any interest in the nice cars of Fleischmann, Roco or many other producers and has never wished to be able to run them on a Märklin-layout? Many have tried - and still are! But there are AClers standing in front of showcases saying: „Well, that’s Fleischmann and our layout is Märklin - that won’t work!“. Or you might experience such a good treat by well trained sales woman like the author had in a shop specialized in model-railways, when he wanted to buy catalogues of Märklin, Roco and Fleischmann: „If you have a Märklin-layout, you don’t have Roco or Fleischmann - and if you have Roco or Fleischmann, you don’t have Märklin!“. Then you here others pretending a flawless usage of such material on their layout - but you have tested yourself and you are not able to confirm this. So, the main question again: Is it possible to use DC-cars on an AC-layout?
Well, it’s possible! But there are some drams to care about - and if you don’t your result will not be funny! The author himself has done many tests during a couple of years with quite a lot of non-märklin-cars und has developed some knowledge of making DC-wagons usable on Märklin-layouts this article is going to present.
Let’s have a closer look at the cars produced by different companies.
It seems the scale is correct (well, more or less), so where’s the problem?
With some watching and testing it’s obvious: the couplers are different
and it seems the axles too. Couplers can be changed easily nowadays thanks to
NEM-pockets and therefor are no real problem - that’s at least how it
should be, but please read on. Checking the axles any differences can’t
be seen that easily. The DC-axles are insulated and the AC aint, but that’s
not of real importance for us. Is it the shape of the axles that is responsible
for a lot of troubles we have with the cars?
Different Wheelset-Design - theoretically
Before solving practical problems we are going to understand the theoretical basics first. We are used to talk about NEM-wheelsets compared with those of Märklin, but strictly seen this is not correct. The NEM (=Norms of European Model-Railways) is a collection of standards fixing a lot of different details in model railways to get independant from the standards of different producers and gain interoperability of stuff. You can find a collection of these norms at „http://www.morop.org/de/index.html“ (sorry, for the present only in german or french, english version in the works). In this article we are talking about the NEM-standard 311 about the DC-models and standard 340 about the Märklin-wheelsets. Just a remark - even Märklin has been fixed by a „official“ standard. Nevertheless the author thinks that it‘s not this norm that will Märklin cause to stay at its wheelset-shape, but more the interest of staying compatible to its own products. In this article we will continue to talk about the DC-wheelsets as „NEM-wheelsets“ and about the Märklin-wheelsets under this name as we are used to do.
Comparison between different wheelsets:
 |
Picture 1: wheelbase-comparison NEM-Märklin, taken from Roco-catalog.
|
| Picture 2: excessive confrontation NEM-Märklin-wheelset - there are four differences in the shape of the wheelsets marked. |  |
 |
Picture 3: Piko-wheelsets, left NEM, right exchange-wheelsets for Märklin |
Having had a closer look at these drawings and pictures and checked the explanations on the Morop-site some of you might agree with that sales-woman mentioned above: Is there any commonness at all between those wheelsets? Beneath the wheelsets the flange-hight, the width of the tread, the grade of the tread and the rounding between tread and flange are different. Except the fact that they are both wheelsets for model-railways they don’t have that much in common!
Rethinking the NEM you might see that as a rule there are no precise values given but minimum- and maximum-values. So NEM-wheelsets from different producers do not need to have the same shape without violating the standard. We will discuss this fetch and the the consequences it has lateron.
Furthermore there’s the well-known fact that us AClers do not need to have all the same track: Some use „M“, others „K“ and the modern ones (or those that feel sick of the tin-track) „C“. The NEM-standard 311 shows, that NEM-wheelsets have been constructed for a square shape of track, but our beloved tin-track has a round shape. So the experiences of many AClers with their non-Märklin-products might result from the type of track they use.
Wheel-set and track interactions courtesy to Gregory Procter
At turnout frogs: the "outer check-rail to frog tip" is the important dimension of the track for guiding the wheels. This is matched by the wheel-set dimension of wheel/flange back to the flange outer face - not the back to back measurement that is normally considered. Obviously, if the check-rail to frog tip dimension is less than the wheel-set dimension then the wheel-set will find its path across the centre of the turnout. If the dimensions are equal then the wheel-set will bounce and chance will decide which route it will take. On the straight route, the wheel will be aligned with both the check-rail and frog gap, but on the curved route the wheel-set will be skewed so the check-rail gap must be wider while the flange tip will effectively be further out across the frog gap.
The frog gap is another "problem area". The width of the wheel tread/tyre plus flange must be greater than the width of the space between frog and its check rail. If it is not, then the wheel can take a incorrect course and drop into the gap and jamb the wheel sideways. The wheel can also drop while taking the correct line through the frog. The purpose of the "check-rail" beside the frog is to provide a running surface for the wheel. If the spacing of the two surfaces is wider than the width of the tread then the support is lost. The original wheel design (1935) from Märklin used the flange tip running on the base of the frog for support. As customer pressure/appearance pushed Märklin to reduce the flange height, they turned to using the wheel and frog more in their correct relationship (although not in double-slip turnouts). They still had to retain frog/check-rail clearances for the older models so this gap is very near it's maximum for the Mä wheels of today. Consequently, NEM wheels that are near the minimum width are too narrow for Mä frogs and cannot be made to operate reliably by adjusting the back to back measurement. Their passing through the frog will always be a gamble. As Märklin frog clearances have varied over the 58 odd years of production of the various track types and this area is subject to wear and distortion, it is almost impossible to state that any type of turnout will work with any particular questionable brand of DC wheel. The addition of shims to the frog check-rail is almost impractical because the end of the shim will be directly contacted by each wheel and will therefore quickly be dislodged. (end of Greg’s text)
The clean...
solution is also a simple thing - changing of wheelsets! Most model-railway-companies nowadays offer exchange wheelsets for Märklin - you put the DC-wheelset out, put the AC-wheelset in and you’re done! If you want to save the money for exchange of the wheelsets, than ask your dealer when buying new cars for a free wheelset-change. This is offered by Roco, Piko and a few others. Anyhow, feel free to ask your dealer for that! Perhaps he’s willing to help you with that issue. The author already was able to get the wheelsets exchanged from waggons bought elsewhere for free with - used - wheelsets, because he was not unknown to the shopkeeper.
Things get more difficult, when fitting AC-wheelsets are not offered. That’s the case with some producers like AKU or Lima. Then you have two check, which AC-wheelsets of other companies fit. Beneath the size of the wheels the distance of the axle-tips has to be correct and the flanges must not be to high. A very interesting adress concerning such problems is the german company „Luck Feinmechanik“ (http://www.luck-feinmechanik.de/). It offers different wheelsets with good quality at a moderate price.
From time to time you might here chitchat that the running quality of cars retrofitted this way wouldn’t be as good as original Märklin cars. The author can’t confirm this; cars with well-fitting axles run as well as the Märklin stuff. But note that e.g. the newer Fleischmann-cars are quite light-weighted and might not run good together with old and heavy-weighted stone-aged cars of Märklin.
and the dirty solution
is the answer to the question on how to make wagons with DC-wheelsets run well on Märklin track. Note that it is depending on some factors whether it works.
We already talked about the track. M and K might give you trouble - anybody not believing this should do the following test: take a Roco-wagon with original DC-wheels and let it run on a Märkin M-curved-turnout from the point to the frog on the inner side - that derailment is nearly 100% reproduceable! But you might also experience derailsment on other critical pieces of track like double-slip-turnouts - some wagons nearly tend to slip between the tracks.
With its C-track Märklin has created a very compromised track: Under normal circumstances even NEM-wheels will run well, the author even has heard that RP25-wheels (NEM, but very low flanges) were usuable. Even more problematic cars like Brawa’s „Talent“-railbus in the AC-variant are considered to run much better on C-track. So if you are using „C“, try to run the DC-wagons first without changing the wheelsets.
Now we are reconsidering the wheelsets themselves. We already talked about the range the NEM-norm gives. There’s a very interesting difference between Roco and Fleischmann. Use Roco-NEM-wheelsets on tin-track and the trouble is for sure - but using Fleischmann-NEM-wheelsets and it works on any sort of Märklin track nearly without any hassle! The Fleischmann-wheelsets are quite well known as compromise-wheelsets, which prove, that indeed a common form of wheels usuable for DC and AC is possible. These Fleischmann-wheelsets are very suitable for bashing- and changing-projects. Its interesting that the new Trix-wheelsets (those that were produced after Trix had been bought by Märklin) do have the same characteristics and also can be used on Märklin track. On the other hand it’s funny to see that these official NEM-wheelsets don’t run well on the new Tillig-Elite track because of there flanges being a little bit to high. But all other wheelsets than Fleischmann or Trix like those of Liliput, Lima, Piko, Heris etc. do have the same character that Roco have and normally won’t be fitting for Märklin M- and K-track.
Some of those experts are thinking about changing the NEM-wheelsets to fit
for Märklin track. Normally the foreigners (seen from the german point
of view) living far away from any sources for original wheelsets have prooved
to have developed a good knowledge in changing the wheelsets. There are three
variants of changements:
- Pressing the wheels together until they have an inner space of 14 mm
- Glueing in thin stripes behind the check-rail of the turnouts
- Glueing in thin rings of tin (ca. 0,3 mm) behind the wheels
Normally the first two tricks are both used at the same time.
The author only knows those possibilities from hearsay because he belongs to those lucky-ones that get exchange-wheelsets with ease. It might be possible to improve the secureness of operation, but the author is not sure whether it’s possible to make wagons run as well than with original exchange-wheelsets.
Finishing this topic it has to be mentioned, that insulated NEM-wheelsets like e.g. those of Fleischmann can’t do any switching on Märklin-track, when both tracks have been insulated from each other and are used as a switch closed by the wheelsets (e.g. the Märklin-contact-rail 24995 „C“). It’s possible to solve that problem using Busch silver-paint. When the paint has COMPLETELY dried (may take some days) these NEM-wheelsets behave like the Märklin ones.
Coupler-Issues
To state that just from the beginning - theme of this part are not the traditional
hook and moving loop-couplers (e.g. the Märklin „RELEX“). Those
couplers are normally quite tolerant in coupling each others. You will get exchange-couplers
for Fleischmann-wagons without a NEM-pocket to retrofit the traditional Fleischmann
moving hook type-couplers.
 |
Picture 4: NEM-pocket Norm 362 (Bild NEMAufnahme362.jpg) |
| and Picture 5 of a wagon-botton - the NEM-pocket as well as the extended NEM-couplerhead can be recognized well |  |
NEM-pocket - that’s the keyword. Correct, under NEM 362 there’s a precisive description of a universal coupler-pocket, which nowadays nearly every producer uses. The so-called coupler-head can be pushed in or pulled out off this pocket. For pulling it out you use needle-nosed-pliers to press the small hooks at the end of the coupler together and then pull it out off the pocket. This way all wagons of different producers can be equipped with the same coupler-head. The best benefit of this technique is that the right coupler-heads and a gullwing aperture in the bottom of the wagons enables them to run buffer-to-buffer in a nature like situation without jamming in curves or on turnouts.
The most usual close-couplerheads (at least in Germany) are the Märklin-CC (No. 7203), the Fleischmann-CC (No. 6515), the long Roco-CC (No. 40270) and the wide Roco-CC (No. 40350). The wide Roco-CC is also called „Universal coupler“. Just for completeness: There exist some more types of coupler-heads, e.g those by Kadee, by RTS (current-conducting) or by Ribu (also current-conducting) - which aren’t of interest in this article.
 |
| Picture 6 different coupler-heads: 1 default hook and moving loop coupler, 2 Märklin-CC, 3 Roco-CC long, 4 Roco-CC wide („universal“), 5 Fleischmann-CC |
Although the Fleischmann-CC has its fans and the Roco-CC is also not rare, for us AC-people only two of them are of importance. On the one hand the original Märklin-CC that Märklin uses to nearly equip any wagon they sell and on the other hand the wide Roco-CC. Both couplers are compatible as well to the traditional hook and moving loop-coupler and to each other. Because of the cost it’s not likely that we will equip all our wagons with Fleischmann-CC or the long Roco-CC. So this article is only discussing those two coupler-types.
 |
| Picture 7 Märklin-CC and Roco-CC wide uncoupled and coupled - please note the different height of the buffers between Roco-wagon (left) and Märklin-wagon (right)! |
The Märklin-CC has the advantages to be very common, to be compatible to traditional hook-loop-couplers, have a pre-uncoupler and to couple very close. It’s most important disadvantage is discussed below. The wide Roco-CC has the advantages to couple very smooth, to have a pre-uncoupler, to be compatible to traditional hook and loop-couplers and to can be upgraded to a current-conducting CC without loosing its other features (see http://home.arcor.de/dr.koenig/digital/estromkk.htm (Dr. König‘s homepage)). It has a small tendency to uncouple within curves. But its biggest disadvantage is the wide distance between the buffers that prevents the author from using it as his default-coupler for non-Märklin-cars.
Why - the AC-user asks - should I use this Roco-CC when I can equip all my
wagons thanks to NEM-362 with Märklin-CC? Well, so he does with his Roco-wagons.
At first it seems to work, but within the very first tight curve or turnout
the wagons derail. Damn - what’s on with the NEM?
We have to give that event a closer check. The height of the pocket is fixed
thanks to NEM, but the height of the buffers varies among different producers
instead the NEM tries to fix that too. The Märklin-CC has the property
to be very high AND wide at the same time, especially when it’s coupled.
Thus in driving tight curves the couplers touch the low buffers, which normally
ends in a derailment. All the other clouse-couplers are either wide OR high,
so no other CC has this problem. It’s interesting to see that the sinners
regarding the buffer-height are just the so called NEM-producers like Roco,
Piko, Liliput, Mehano and some others. Their buffers don’t have the minimum
height of 9.8 mm beyond the rail-top fixed in the NEM 303. It’s likely
that this happens because of their efforts to stay as close as possible to a
correct reproduction of the scale of wagons. The Fleischmann-buffers fulfil
that norm and the Märklin-buffers even are higher - as it was expected.
The author can already hear many of those ACers saying that this and that and quite a lot of his Roco-wagons perform well with the Märklin-CC. This indeed may be. The reality is even more ambiguous than it might have appeared so far - there are some rules of thumb helping you to identify the wagons working well with Märklin-CC, but the main rule is: you have to test each wagon individually, which coupler-heads fit. You also might exchange all wagons to Roco-wide couplers, but you will throw away all those existing Märklin-CCs and have to buy Roco-CC for quite a lot of money.
These rules of thumb are as follows: Märklin-wagons normally do not need to be retrofitted (except they are very long and are intended to couple well with Roco-wagons). Roco-wagons need to be retroffited very often. With Fleischmann-wagons it depends: especially the shorter ones might be ok with Märklin-CC, but the longer the wagon the more you have to be aware it needs the Roco-CC. It is more likely that long wagons have to retrofitted with Roco-CC than short ones. The wagons of many other producers also have to be tested very thoroughly. If you have a wagon with Märklin-CC that tends to derail exchange as a first action the CC with that of Roco. Contrary to the opinion of many model-railroaders the weight of the wagons is not that important as long as the train isn’t too long.
During the years the author has found a quite sure way to recognize the wagons which have to be retroffited with Roco-CC. Just take from your rolling stock two well running original Märklin-wagons still having their Märklin-CC. They shouldn’t be too short and should be well tested. Couple them to a loco and make this little train run around your layout, but not too fast. Derailments should not happen, otherwise your layout isn’t well set out ;-O or the wagons are not suitable. When all is well, take the wagon to test (should have Märklin-CC in this stadium) and couple it BETWEEN those two wagons. Repeat driving the train around the layout - at first slowly, than faster. If nothing happens, all is well. But if the wagon under test does not perform well with Märklin-CC, you might expect to spot it at the first tight curve or turnout - one or more of the wagons will derail. It doesn’t matter whether the wagon under test derails or any of the others. If you can repeat those derailments for sure, you have to exchange the CCs. Test the wagon again with the Roco-CC and all should be well now. If it is not, the coupler wasn’t responsible for the derailment. BTW, you have to make sure the wagon has well performing wheelsets BEFORE you do this test.
 |
| Picture 8 Using the test-train - wagon under test (Mehano) in the middle |
Exotic problems and other questions
There are some problems with non-AC-wagons, which neither are wheelset nor coupler related, but should be mentioned here shortly:
Especially long wagons tend to have problems with the turnout-lanterns of old M-track. There’s not much what can be done if you don’t want to change those wagons badly - either forget them or better: skip those old tin-tracks!
Roco and some other manufacturers manufacture some really beautiful passenger-coaches, that are 30.3 cm long (modern german passenger coaches do have an original length of 27 meter - which makes all those Märklin-models wrong in scale). You should NOT use those wagons on Märklin-track, at least if you are not willing to pay the same price Roco is paying for being able to use them. This price consists of raising the minimum radius of curved track from 36 cm to 42 cm. You need such a big radius to be able to operate such wagons without hassle. It’s possible to built Märklin-layouts with such a big default radius, but normally it’s not done because of lacking space, although the result would be a better looking layout. If you try to use such long coaches on 36 cm radii, they might collide with catenary-masts, signals, tunnels and other obstacles. And they will look very ugly because of the long excessing ends in the curves.
„I would like to use wagons with short-couplers, but those neither have a gullwing aperture nor NEM-pocket“ the ACer asks. Well, there are two ways to solve that problem: Roco offers a complete coupler-holding to be fixed below the bottom of the wagons. (Order-# 40343 or 40344). This solution cannot be used for a lot of bogie-based wagons und needs an experienced hobbyist. The second solution to that problem are the Symoba-coupler pockets (SYMOBA Modellbahnsysteme Schniering e.K. An der Rottriede 3, 49637 Menslage - www.symoba-schniering.de). They are smaller and can easily be glued to the wagon-bottom, which simply needs to have been ground flat. They also fit for bogie-wagons. Gützold offer those holdings too (Order-# 01170).
 |
Picture 9: Coupler-holders by Roco (left) and Symoba (right). The Symoba-holding is smaller and can be adjusted in height |
What can be done with those coupler-heads we had to take out because they did not met our system? Don’t discard them! Change them with your friends or sell them via EBAY, they get paid well!
Outlook
Well, that’s the end of our small description on the use of non-AC-wagons on Märklin-layouts. You will soon recognize, that following these hints you will be able to make the biggest part of all non-Märklin-stuff run well on your layout. This will enlarge the choice on wagons you have significantly and you will even get clear with those nice gifts which were nearly worthless before.
There’s one final question lying in the air: If it is that easy to make wagons run well, doesn’t it make sense to change the locos too? Sadly this is much more difficult and can’t be done following some simple rules. Beneath the wheels and the couplers you will have additional problems with locos. The electric equipment has to be changed and a pick-up-shoe has to be fixed. But the biggest problem is the changing and correction of the wheels. You can’t that easily exchange wheelsets on locos like you can do that on wagons. Just imagine a steamer - say - 2-8-2 (1D1) - . The trailing and following axles are a minor problem, but the driving wheels need to be exchanged by exactly fitting wheels, which you do not get that easily, because of such details like wheel size, counter-weights, fitting of the rods, diameter of axles etc. The modification of existing wheels may contain a lot of critical problems too. Furthermore because of the higher flanges you need for AC you have to expect that there is not enough room for them on many DC-steamers. So if you want the authors opinion: if you can, go for the locos already produced for AC by the manufacturers. It might save you a lot of hassle.
Ulrich Röcher
| back |