Hello,

K track turnouts use engine 7549 or 75491.
There is no embedded decoder below the track for K track, as they are for C track.
Thus, you need to have an external decoder (able to drive 4 turnouts), like a M83 ref 60832/60831 if you wish to stay with Marklin.
You may also find equivalent decoders at Viessmann (ref 5211 -old design) or new design have same function as M83 (ref 5280).
Other alternative may be found at LDT (S-DEC-4 family).

Last thing: the underfloor mechanism 7548 is not very reliable.
A reliable solution is to go for servos, produced by ESU + a servo decoder... but this is more complicated to setup and only valid for permanent layouts.

Cheers
Fabrice

Hello Marco,

ESU servos need to be driven by a special decoder, also produced by ESU (other brands exist also, but I'm familiar with ESU).
This special decoder replaces the M83. M83 is not able to drive servos...It is only for dual coil engines

ESU servos ref 51804: http://www.esu.eu/en/pro...t/precision-servo-motor/
ESU servo Switch Pilot Servo v2 decoder ref 51822: http://www.esu.eu/en/pro...t/switchpilot-servo-v20/
You may also need cable extension, from servo to decoder, ref 51810
Go to ESU web site and download the doc for switch pilot servo v2.

Then, there are a number of things which are a bit tricky, or at least need some attention.

1) How would I connect the servo lever + the piano wire to the turnout ? the most difficult in my opinion...
2) How would I program the ESU decoder ? very easy if you have an ESU Lokprogrammer (I know, another investment...)

About 1) with K track turnout, you have at least 2 possibilities :
a) the one I use: I use only the upper part of mechanism 7548 (top part), then thru a hole 10mm diameter, the piano wire goes into the lever provided by 7548 kit
b) other option: you may modify the handheld lever of the turnout by inserting the piano wire from below. Never went that way, but I've seen it on some layouts.

About 2) either you program the CV of ESU decoder with your command station (with CS2 it is extremely boring, with CS3 I hope it is easier) in order to adjust the servo movement, or you buy an ESU lokprogrammer and it is very easy with the dedicated software -valid for all ESU programmable devices, including loco decoders.

There are a number of layouts here which use ESU servos. See applor's layout, probably river6109's layout, possibly others (JohnJeanB ?) and my layout.

If you want to see some shots of servo setting, look there: https://www.marklin-user...-Left-sidings#post598104
and there: https://www.marklin-user...-Left-sidings#post598730

Last advice: Just test servo setup on a workbench before going to the final layout... At the beginning, it is not obvious... When you know how to do, it is rather easy, but you need to be very precise...

Cheers
fabrice

Edited by user 25 June 2020 12:26:16(UTC)  | Reason: Not specified

as Fabrice says the underfloor mounting mechanisms are awful.

Another solution is to use the Märklin switch motors but mount them above the surface but upside down.

see https://cabin-layout.mixmox.com/2004/12/switch-motor-modification-thread.html

for how that can look and how you can actuate it manually when you need to.

I can also confirm that ESU servos mounted underboard with the cover from the marklin 7548 is really the only way to go. Installation options are quite flexible and the servos are 100% reliable.
I have done this for all my visible turnouts using the Switchpilot servo 2 decoder (4 servos per decoder)
I use the standard Marklin switches for the hidden areas.

You can see them installed in my layout thread.