Rebuilding Märklin 3417, NSB 63a 2770, to digital with Märklin conversion set 60901 and mfx sound decoder 60931
Märklin 3417, NSB 63a 2770
During the second world war the Germans brought 74 of their Br 52 to Norway. When the war ended, the locomotives remained in Norway and was used by NSB. This was a very valuable addition to the existing locomotive park, and gave NSB more time to supply new Diesel locomotives. The last NSB series 63a retired November 9th 1970.
Preparations for the conversion:
I always start by removing everything; the reversing unit (in the tender), the motor and all the wiring, including the wires to the front lamp and smoke generator contact tongue.
Normally I separate the locomotive and the tender during the conversion. It should not be necessary in this case.
Make sure that all the mechanical parts, like the gears, axels, rods and other moving or rotating parts works perfect before starting to install the new parts, in the following sequence:
1. new motor
2. decoder with the wiring and speaker
3. cabin light
The motor parts from the Märklin conversion sets 6090, 60901, 60921 and 60760 may be used. Basically, only the decoders are different in these sets. The new motor set 60941 suits perfect. In this case the conversion set choise doesn't matter, as a separate mfx sound decoder, Märklin 60931, is used. Installation of the motor itself is very simple. After removing the old motor, make sure that the mechanical parts are clean and work perfect. Axels, rods and gears must rotate smoothly. If necessary, oil the moving parts very carefully. After installing the new motor, without the brushes, check again that it all rotates perfectly. Then install the two brushes. The below photo also shows the orange and brown/green wire to the interior light connector.
Decoder and speaker:
I stripped the decoder for it's rubber cover and glued it with a green detachable stuff to a decoder holder, Märklin part number 258820. This holder fits in the tender tub. I glued the two noise suppressors for the motor in the bottom of the tub, under the decoder holder. The orange wire from the decoder is soldered to a distribution pcb (Printed Circuit Board) glued to the RH inside of the tender tub. The orange wire is distributed to the rear lamp, the front lamp and to the connector for the interior light in the locomotive. Also the brown ground wire has a distribution point on the pcb.
The speaker is installed where the cylinder shaped weights used to be. By cutting off most of the centre divider and filing off a little bit of the speaker plastic house, it was possible to press fit the speaker house into the coal box.
The decoder functions:
See below table.
Front light and steam generator:
The grey wire from the decoder goes all the way forwards to the front lamp, with an orange wire. These wires are soldered to the lamp holder. Also the brown/red wire for function f1 goes all the way forwards, soldered to the contact tongue for the steam generator.
To keep the good running performance, I had to put the removed weights back in the tender. I fixed them together with insulating tape and just put it on top of the rear lamp. It is held into position by the rear wall and the lateral divider.
Interior light in driver's cabin:
A small 28 volt T1 bulb is glued to the rear end of the driver's cabin ceiling, indicated by the gray arrow. The wires go through a slot in the RH side of the driver's cabin. The connector is glued to the locomotive body. A 330 Ohm resistor is soldered to the connector, to reduce the voltage to the bulb, to reduce the light intensity.
My setting of the decoder:
|Decoder settings, 3417||Default||Mine|
|Enable analogue mode||check||<|
|Control settings :|
|Control parameter K||60||<|
|Control parameter I||120||<|
|Driving Sound Rate:|
|At min. speed||1,000||<|
|At max. speed||1,512||<|
|Braking Sound Threshold||14||18|
My Märklin 3417 NSB 63 2770 decoder functions:
|3417 NSB 63a 2770|
Screenshot from my Central Station 1:
To the left Märklin 3417 NSB 63a 2770, to the right Märklin 37158 NSB 63a 2843 with original mfx sound decoder
Some prototype information about the DR Br 52, from Wikipedia
|Number(s):||see Wikipedia text|
|Quantity:||More than 7000|
|Manufacturer:||see Wikipedia text|
|Year(s) of manufacture:||1942 - ca. 1950|
|Retired:||ČSD: 1976 |
|Axle arrangement:||1'E h2|
|Length over buffers:||22.975 m|
27.532 m (with condensing tender)
|Overall wheelbase:||9.2 m|
|Service weight:||84.0 t|
|Service weight incl. tender:||102.7 t|
|Adhesive weight:||75.9 t|
|Top speed:||80 km/h|
|Indicated Power:||1,192 kW (1,621 ps)|
|Driving wheel diameter:||1.4 m|
|Leading wheel diameter:||0.85 m|
|No. of cylinders:||2|
|Cylinder bore:||600 mm|
|Piston stroke:||660 mm|
|Boiler Overpressure:||16 bar (1.6 MPa)|
|Grate area:||3.89 m2|
|Evaporative heating area:||177.83 m2|
|Tender service weight:||18.7 t|
|Water capacity:||27,000 l|
ÖBB covered tender = 30,000 l