tip: lokpilot micro conversion of märklin 3423 wismar...

Tip: LokPilot Micro Conversion of Märklin 3423 Wismar Bus Date: 07-05-2012

http://members.ozemail.com.au/~rossstew/rms/marklin.html 1

Hi All,

This project just started out wanting a simple upgrade from a Delta decoder to a LokPilot Micro V4.0

decoder. I’ve had this loco since it was released in 1994, made by Bemo and marketed by Märklin and

was never very happy with the way it ran and not having any switchable functions. Since that time it has

been stored in its box waiting for a better decoder, that time has now arrived. I wanted to add LED lights

for the cabin lighting and to have a prototypical speed of 100 km/h.

Photo above includes the cabin lighting turned on.

Warning: - You undertake the following modifications at your own risk.

Cabin LED Lights

I decided to try something new for the cabin lights by installing a LED lighting strip (12V dc) that has a

self adhesive backing. To this I soldered two 1N4148 diodes with the anodes connected together and

soldered to the (-) side of the strip. To the cathode of each diode I soldered a length of wire, yellow and

white. A blue wire was soldered to the (+) of the strip. I then used a 3 rolled pin IC socket to make a plug

with the blue wire in the middle. The diodes are covered in heat shrink and the LED light assembly is



stuck to the metal weight in the roof. The wires for the Micro decoder were just long enough to be

soldered directly to the motor.

The arrows above (page 1) mark the connection points. On the red arrow a red

wire comes from the collector shoe and the decoder to the same solder tab.

CV Values for the LokPilot Micro V4 Motor and lighting effects

Warning: Make sure you read the ESU decoder instructions before programming

any CV’s

Ensure CV31=16 and CV32=0 before changing any Lighting Control Settings.

Set the brightness value first to a low setting before turning the lights on. There should only be

12Volts DC maximum across the LED lighting strip connection points.

With the above Lighting Control CV configuration the cabin light increases in brightness using “Rule 17”

when the locomotive moves.

Because the motor is only a three pole motor I set CV54=0 then switched on F1 function key to

automatically set CV52 ...CV55 and the results can be seen above.

The results when trying to run the locomotive on the track were very poor as it kept stopping all the time.

Description Colour

Motor R Grey

Motor L Orange

Ground Black

Centre Rail Red

+ Pole Blue

Head Light White

Rear Light Yellow

Motor Settings [Index:0 (CV31=0, CV32=0)

CV# Name Range New Default

1 Primary Address 1-127 8 3

2 Start Voltage 1-255 3 3

3 Acceleration 0-255 6 8

4 Deceleration 0-255 4 6

5 Maximum Speed 0-64 31 64

6 Medium Speed 0-64 10 22

51 Load Control Parameter “I slow speed” 0-255 *0 0

52 Load Control Parameter “K low speed” 0-255 42 32

53 Control Reference Voltage 0-255 81 140

54 Load Control Parameter “K” 0-255 48 48

55 Load Control Parameter “I” 0-255 42 32

66 Forward Trim (1 x Voltage) 0-255 128

95 Reverse Trim (1 x Voltage) 0-255 128

Function Control Settings [Index:4096 (CV31=16, CV32=0)

Function

Output

Mode Select Brightness 0-31 Special Function

CV# Value CV# Value CV# Value

Head Light[1] 259 2 262 6 263 132

Rear Light[1] 267 2 270 6 271 136



Fine Tuning the Locomotive

Each time it stopped I would push down on the locomotive, it would start once again then after a small

distance it would stop once more. I made up my mind to persist trying to find the reason why the

locomotive wasn’t running as expected.

Looking at the bottom of the locomotive you can see it only has one rubber tyre. I noticed that the

locomotive ran better in reverse than it did in forward on my test track. By rotating the locomotive 180

degrees it improved for the forward direction, this indicated that the ground/masse on the chassis was

very poor. Because I use TrainController, one rail is a contact rail for train monitoring and the other rail is

the return supply rail, this made it obvious that in one direction only one wheel was being used and in the

other direction two wheels were being used for the power pickup.

Wheel Pickup Improvement

I disassembled the wheels from the locomotive and

saw that the chassis was painted where the axle

bearings sit and also the bronze pickup spring also

sat on a painted area. The paint acted as an

insulator for the chassis so poor ground contact

was the result.

I removed the paint where the axle bearings sit at

both ends of the locomotive and also removed the

paint where the pickup spring sits.



Locomotive Weight Improvement

On closer inspection I also noticed that the collector shoe spring was quite strong so as the locomotive

went over points it would stop because it would lift the wheels to have very little contact with the rails.

I had some fishing led

sinkers that I beat into a flat

shape then cut and filed to fit

each weight shown left.

The wedge shape weight was

used in the engine at the

decoder end of the

locomotive.

The top two thin weights

were fitted over the wheels at

the decoder end of the

locomotive.

The bottom two thick

weights were fitted over the

wheels at the driven end of

the locomotive.

All the weights were painted black and had a firm fit, but still removable if service to the locomotive

wheels required attention at any time. I’m not sure how much weight was added to the locomotive but the

limiting factor was the available space.



The photo above shows that I have blackened the wire colours and the edge of the printed circuit board

(PCB) with a permanent marker to improve the view of the cabin through the windows.

The final results were well worth the

effort both in looks and improved

running.

All original parts have been kept to

allow someone to return the

locomotive to its original state.



Speed profile for TrainController with the maximum speed set at 100km/h

Parts required:-

As always enjoy your model trains.

Part

Number

Supplier Description Quantity

54683 ESU ESU LokPilot Micro V4.0 Decoder 1

51940 ESU White cable, 0.5mm diameter, AWG36, 10m 1

51942 ESU Black cable, 0.5mm diameter, AWG36, 10m 1

51943 ESU Red cable, 0.5mm diameter, AWG36, 10m 1

51944 ESU Orange cable, 0.5mm diameter, AWG36, 10m 1

51946 ESU Grey cable, 0.5mm diameter, AWG36, 10m 1

51947 ESU Yellow cable, 0.5mm diameter, AWG36, 10m 1

51949 ESU Blue cable, 0.5mm diameter, AWG36, 10m 1

102-3035 Element14 Harwin SIL Socket 32Way D01-9973242 1

108-1177 Element14 1N4148 Signal diode 2

tip: lokpilot micro conversion of märklin 3423 wismar...

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