CONVERSION OF THE MÄRKLIN LOCO 3338 TO DIGITAL
The items used for the conversion are: A new five pole motor, Märklin kit 60941, (See datails below) and a decoder from ESU typ LokSound V4.0 together with a speaker. Functions programmed as follows: F0: Front/rear light with Swiss light functions, F1: Sound on/off, F2: Whistle, F3: Short Whistle F4: Fans, F5: Compressor, F6: Shunting mode/speed, F7: Curve squeel, F8: Aux 1 (not used), F9: Compressed air let of, F10: Conductors signal, F11: Radio communications, F12: Station announcement, F13: Station announcement, F14: Station announcement, F15: Station announcement, F16: Door open/close F17: Rail clank, F:18 Sanding, F19: Brake set, F20: Short wistle, F21: Coupler clank.
The sounds used are originals from the loco including sounds of squeaking brakes.
The standard lightbulbs are changed to warm with light diodes. (LED:s)
The first step is to remove the top cover from the chassie. The only screw to remove, is to be found on the bottom side of the chassie. Next is to remove the motor-truck from the chassie. To have access to the truck, the screw holding the coupling has to be removed first, together with the frame surrounding the wheels. The truck is a little bit tricky to remove, but turn it sideways, and press it backwards, and it will leave the chassie without protests.






The dismounted motortruck, showing the original motor, together with the cabeling to the pc-board, holding the light-bulbs, to one end of the loco.






All motorparts now removed from the truck. The magnet and the pc-bord for the light-bulbs are still connected to the wire-harness.






Side view of the Truck, ready for installation of the parts to the new 5-pole motor.





Top view of the Truck.




All items for the new 5-pole motor before installation, with the armature, field magnet, bearing-plate and the two connecting components for each pole of the motor. All motor parts were separately choosen at my Märklin supplyer, to be shure that all of them, will fit at the space available for each item.





Side view of all motorparts, installed on the Truck.





Top view of Truck, installed with all the parts for the 5-pole motor..




Motortruck back in place in the chassie.




Lightbulbs are changed to LED:s on the original PC-board without any soldering. When cutting the "legs" of the LED:s, don´t forget to marke the polarity, so the LED:s will be connected with the correct polarity. (See my red markings on the LED:s, seen when enlarging the picture)




When using LED:s you always have to use some type of resistor, to be able to feed the LED:s with the correct power. Recommendations of usable resistance in each case, is often given by the producer of the LED:s or by the producer of the decoder. Different values of the resistor affects the brightnes and the heat produced by the LED. Don´t choose to low resistance on the resistor when testing your optimal brightness of your LED:s. Solder the resistor on to the PC-bord before fitting the LED:s. They don´t like the heat from the soldering iron.




After soldering the LED:s on to the PC-board, check it on place, so there is no connection to the loco chassie. For safety, I have used some extra insulation.
See picture below.




Make a small wire harness, from each of the two lighting PC:boards, for later connection to the decoder. Connection is done according to the instructions, given in the booklet from ESU, to obtain Swiss lighting configuration. For bundeling of the cables, I used Nylon and Dacron flat braided tape, supplyed from Alpha Wire Corp N.J, USA.




Picture showing the wireharneses for the lighting on both ends, leading out from the old "main" pc-bord, together with the pc-board with the diode-bridge, used for creating the Swiss lighting configuration. All the items are to be removed from the chassie, together with the ferrit-core "filter"(taped on to the main board) connected to the power feeder.






Remover the holder for the main pc board from the chassie.





Close up up the old main pc-bord (Umschaltelektronik) Märklin art no: 630540.





Close up on the old pc-bord (Wechsellicht) Märklin art no: 622550




The new ESU decoder LOKOSOUND V4.0, in the position where the old main board was installed, thogter with the speaker. There is verly little exta space availalbe sideways for the speaker, when the cover is to be put back on. An alternativ way to install the speaker, is in the cover between the plastic "furnishing". The cable from the speaker to the decoder is long enough.




The complete installation seen from the top, together with the new cableharneses to the lights.





Installation seen from the side. I have used the extra cable harness availabel from ESU, fitted with an 8-pole connector, art. no. 51950, matching the one supplyed with the decoder.
Easier for service of the decoder. No changes and soldering is done on the decoderunit as such.




Pay a little extra attention to the cables passing by the motortruck, so the truck can swing freely. Fit the cables with a little bit of slack.
FINAL ADJUSTMENTS FOR THE MOTOR:
A final adjustment of the decoder was done, to fit the Märklin High performance 5-pole motor according to the ESU booklet. Special attention was taken to the s.c. K (CV54) and I (CV 55) parameters. My motor-CV:s was adjusted as follows:
CV2:3, CV52:32, CV53:120, CV54: 60, CV55: 95 and CV 56: 255.
Everything now works excellent, with very nice speed caracteristics.