Updated 27 Sep. 2002


Retrofitting old locs. with 6090(x)


08-12-2013 Note !:

This article was written in 2002 and since then, retrofitting has become somewhat easier, and better components

has become available from Märklin. There are the 60943 which has an all new motor for older Locos with SCFM

motors, and the 60944 for Locos with LFCM motors. After the motor has been upgraded, you need a decoder.

Also here Märklin now has a bigger selection including sound decoders. Else ESU's Lokpilot or loksound are great

decoders, and in some cases more versatile and cheaper.

Mounting boards are also avaliable if you want to use 21 pin decoders - this will make soldering less critical.




As you may know the advantages with the 6090(x) system is :


In order to convert a loc to 6090(x), your loc must normally be fitted with a drum-commutator.

It IS possible to get all the advantages of the 6090(x), even if you have an older loc, who use :


LFCM (Large Flat Collector Motor) Or SFCM (Small Flat Collector Motor)


What you need is a permanent magnet which can replace the electromagnet, that the loc is fitted with.

The magnets from the HAMO-locs, are just what you should use.

If you have locs based on a LFCM, then you need the 220560.

If you have locs based on a SFCM, then you need the 220450.

A comparison between the two magnets (62K)


In principle, you can convert all locs with 6090(x), as long as you can fit the 6090(x) decoder in

the loc. However I have encountered several instants where the 220450 cannot be fitted, unless

you do some milling(cutting) in the motorshield.


If you concluded that the 220560 are the magnet you should use, then let me tell

you that there is an alternative to the 220560. It's a stronger magnet, and it consists

of a 220970 (which is a 220560 without the magnet) and two 7558 magnets.

The 7558 magnets are smaller than the normal magnet, so a spacer of some kind is

needed. I have made one in balsa-wood, which is soft and can be pressed to fit.

The spacer just need to fit, and be non-magnetical. From my experience with the

7558 magnets, I can say that the performance is a bit better than with the normal magnet.

The locomotives run a bit smoother.


 Here's a couple of pictures of the 7558 magnets and the spacer

 (click on the pictures for a larger view)





I have been given some even stronger magnets - so strong that you can put on each side of

your hand, and they will stay there !. The magnet look very similar to those which can be bought

from Conrad. They look very much like them (small and round) but i don't know how strong

the ones from Conrad are.

BUT, I found these magnets to be almost too strong. At low speeds the motor frequently stalls

because the magnets almost "locks" the anchor. They seem to work better in large locos, because

of the bigger momentum, but in small locos its not that great.

So maybe there are such a thing as a too strong magnet.

   Very strong and small magnets  Click to enlarge picture !

   The magnets cannot be closer to each other without jumping together !!!



So - what do you do ?.

Of course you start of by buying a magnet and a decoder - The decoder would be the 60901.

You could also by the 60902, which is the decoder ONLY. This way you don't have

to pay for a magnet you don't use.

Ok ! - The following is how I converted a 3022(E94) using a 220560.

Start by unsoldering the wires from the existing decoder/direction changer and the electromagnet.

This is how the 3022 looked before, note the existing 6080 and the electromagnet  

overview before the conversion - Click for a larger picture !

Another larger picture is available (80K)

Now simply mount the magnet, where the electromagnet used to be, - It should fit perfectly.

Here's a comparison between the HAMO-magnet and the Electro-magnet (44K)

Now solder the wires as described in the 6090 booklet. - It's that simple ! (for the 6090x decoders go here)

Here are the finished result !

The magnet mounted in the 3022

 You may experience bad driving characteristics and/or bucking/"jumping" behavior after

you have converted your loc. This problem can be solved by using one or two 4,7Ohm/5W

resistors in series with the motor. The value of the resistors(s) is not critical, - try out smaller

values first.

The resistors should be soldered in series with the small inductors (the ones that looks like a resistor -

look at picture above). Solder the resistors between the motor and the inductors.

like this :


 Examble :


Remember !!.

It's NOT absolutely necessary to use two resistors, NOR to use a value of 4,7Ohm.

You should experiment both with the value and the number of resistors.

Try with ONE resistor first. ( I have had good experiences with only one 3,3Ohm resistor )



Here are a couple of other pictures of the finished result

The Motor

 The magnets

A view of the finished motor


Another view of the motor


The 220560 (73K)

The 220560 with magnet taken out (84K)

The 220560 with magnet taken out, viewed from another angle (69K)

A full view of the 3022

 Picture #1 (59K)                        Picture #2 (59K)                        Picture #3 (61K)

Note the holder for the 6090-decoder. It's simply a piece of bend Brass.

Also note the piece of printed circuitboard behind the decoder, this is the the flicker-eliminator


The 220450 MagnetIn case you want to convert a loc using a SFCM(220450), I have made a couple of pictures of that.

The pictures show how the 220450 fit in a 3000 (BR89), which are

one of Märklin's smallest locomotives. The pictures only show how

the magnets fits NOT the decoder, as I am not sure a 6090(x) would

fit in a 3000.


But as I stated before,



It may be necessary to cut the small plastic dots (look at the picture) smaller or cut them away, in order

to fit the 220450 on very old locos. You shouldn't worry about cutting the dots, as the two screws are

enough to hold the magnet in place. I have tried cutting the dot smaller by cutting a bit off from 4 sides,

so the round dot becomes a small square dot. But be aware that milling may be required to the motor-

shield in order for it to fit over the magnet.

The pictures regarding the SFCM and the 220450

 The anchor

 The magnet fitted in a 3000

The SFCM anchor (27K)

The SFCM anchor from another angle (42K)

Same anchor from yet another angle (31K)

 Note. This loc are not being converted. The pictures are ONLY to illustrate that  it it can be done(the magnet fits!) this is why you also see the electromagnet on  the pictures.

A view of the magnet + anchor mounted (62K)

Close-up of the above. (86K) *Note the free space between the anchor and the  magnet !

The "completely" assembled loc. (69K)

The "completely" assembled loc, from another angle. (59K)

 For further information about this subject

Check out these pages by Axel hagel

Retrofitting your older marklin locomotives with 6090

Comparison of the 648680 and 61409 high efficiency (c90) decoders


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Email :kenneth@pallund.dk