Märklin 3511 Dampflok Klasse C der K.W.St.E. is one of the most appealing locomotives I have in my collection - it simply is worthy of its nickname "Die Schöne Württembergerin". I also liked the unusual technology Märklin equipped this model with: it has a Faulhaber motor operated by means of an electronic controller that provides smooth acceleration and deceleration and adjustable top speed. Debuting in 1988, the 3511 represented a kind of apotheosis of Märklin analog.

Sadly, my copy of the loco was not quite right. It was never a good runner, no matter of how I tried to adjust the potentiometers of the controller board. It was also quite reluctant to reverse direction, especially before running it for a while. Recently, the controller simply gave up and stopped even pretending to provide power to the motor. Upon inspection, one of the condensators had become loose; apparently the old surface mounts had failed.

So, I had to accept the inevitable and convert the locomotive to digital. I share my experience because there are a couple of details that others may find useful.

The conversion itself is quite straightforward. The Swiss manufacturer Lüssi Hobbyartikel provides a "Leiterplattte" that exactly matches in shape the old controller board and has a 21-pin connector for a decoder. One simply has to resolder the six wires that went to the old board and stick in the decoder. I chose to insert a mLD3 decoder as I had one handy.

Then I had to configure the decoder to fit with the Faulhaber motor. As so often before, the HGH-Moba Web pages proved useful and gave a list of presumably suitable values for mLD3, viz.

CV 2 CV 52 CV 53 CV54 CV55
2 4 150 64 64

The first tricky part was how to enter the CV's, given that I only have a MS2 that does not support CV editing for mfx. With DCC it nevertheless has a rudimentary interface, so I switched the MS2 to DCC mode and used that to talk with the decoder. It responded appropriately through the DCC default address 3 and I was able to give the values. After I re-enabled all protocols with MS2, the locomotive registered automatically to it and operated as expected. So far so good.

The second tricky aspect was how to introduce the locomotive also to Rocrail. The problem is that the address the MS2 assigns to a new mfx decoder is not based upon the decoder address (Motorola address), but is chosen automatically. MS2 does not show that address, yet this is the one that I would need to give to Rocrail. The solution turned out to be to operate the locomotive with the MS2 - say, turn the lights on - and then take a peek into the Rocrail trace that dutifully recorded the related CAN bus events. Then I saw that the address was "7". Indeed with this address, Rocrail was able to command the logo as usual. (CS2/CS3 owners can see the address in the locomotive configuration dialog, so they will not need to bother.)

So, now I have a digitalised 3511. While losing on authenticity, it is now a solid performer that does its jobs perfectly.

Mine has no sound. I had my former dealer who was also an electronics expert in the old TV/stereo field convert it to digital in the late 90's. It runs well. A slight buzz at slower speed, but disipates.

Hello everyone

I am also in the process of converting my 3311 to digital.
Is the difference between 3511 and 3311 the presence or absence of motor load control?

A photo of the renovation.


I installed the 60975 and speakers, and installed the M37118 project from the marklin site, so I can enjoy the sound equivalent to the 37118.
The top and tender lanterns are out of order, so I'm at a loss as to whether to buy lanterns, repair them, or make my own.

I'm ordering seuthe #21 because I want smoke, but I don't know if it will work.
Since the top light unit and the chimney are close, there may be a problem.
Looking at the 37118 manual, it seems that the smoke unit can be installed as an option, but looking at the 37118 photo, there is no top light lantern.

Has anyone installed smoke unit?

Nice work.
Installing a smoke unit is possible and the seuthe #21 should fit. But you have to run an extra wire from the decoder and forward to the smoke unit. Judging from the pictures you should have no problems doing it
you have two options with the wire. assuming the construction is similar to in my 37112 and 31021.
1 is to run the extra wire above or below the print plate in the frame, or make a new one
2 is the run the extra wire inside the boiler.
Take care around the motor and gears etc so you don't get the wire into the gears and make sure the wire is not squeezed/damaged when you put the cover back on.

recommend buying new lanterns if you can find a seller, as they are easy to replace.

Another tip if you have the original Faulhaber motor, is to set the MSD3/LD3 to motor type: 4 bell anchour (CV 52=4), and then perfom the automatic calibratio,n acording to the manual. that will most likely give best result, use presets only if you are not happy with the calibration for some reason. (and remember the CS3 bug in the English software related to the setting of the motor type, no other language is affected.)