Updated 22.01.2014
The Märklin 28452 set:
The Märklin set was made by Märklin in 1999 and 2000 for Holland, with three
different cars.
Why rebuild a Delta locomotive?
Why rebuild it, as it already has a Delta decoder, which enables digital
operation?
Six, for me, good reasons:
1. The new decoder is adjustable, so I may achieve the prototypical correct max.
speed, which is 60 km/h.
2. The acceleration and braking delay is also adjustable.
3. The new 5-pole motor runs very smoothly.
4. If using a braking module at a red light, the locomotive will come to a slow
stop in front of the red light
5. Possibility to switch the light on and off, as well as the light may be on
while the locomotive is stationary.
6. Possibility for internal light.
Märklin 28452-1, DH 360 Ca
I think this is the only 3078-based locomotive from Märklin with connecting
rods.
The locomotive inside before disassembling:
Disassembling
Very simple to explain: remove everything. After removing the pick-up
shoe, unsolder the small contact plate. Unscrew the
two screws on the motor cover and the decoder from it's holder. Then it should be possible
to "lift out" the reversing unit and the motor in "one piece".
I carefully pack these parts in a small plastic bag and store them. Remove
the decoder holder.
I removed the "axel covers", not to damage them.
The pick-up shoe and it's contact plate, the motor screws, the soldering lug and
the brushes will be re-used.
The disassembled locomotive:
I kept the wires from the bulb sockets, as they are difficult to access under
the locomotive. The yellow, grey and front brown wires were soldered
directly to the new decoder. The rear brown wire was soldered to the
interior light's orange wire. See wiring diagram below.
Conversion parts:
For the 28452 the conversion sets 6090, 60901, 60921 or 60760 may be
used, or the new motor set 60941, as the motors in these sets are identical.
If using the 60941 motor set, a separate decoder set, for instance the mLD (märklin
Lok Decoder) 60962, may be used.
Decoder:
In this case I used the decoder is from a 60760 conversion set, installed where
the Delta decoder used to be. It is supposed to be installed in the holder 456200,
but I had none left in my box, so I have to order more from my Märklin dealer.
This decoder gives 14 speed steps, which I find more than enough for the
prototypical top speed, 60 km/h.
The 60760 decoder is rather simple, but I selected this decoder for it's
adjustability, especially the top speed. I had the decoder in
stock from an earlier conversion.
Motor:
Installation of the motor itself is not difficult. After removing
all the existing parts (motors, reversing unit, bulbs etc.), clean the chassis
and make sure that everything (transmission and wheels etc.) is turning
smoothly.
Install the new motor to the locomotive, firstly without the brushes. Check once
more that everything revolves freely. Install the brushes.
The new locomotive inside:
Decoder holder 456200 is missing, so I have to buy some more.
Interior light:
Small yellow smd LEDs were glued to both sides of the "tower" for the body screw, over the
motor. An orange wire form the decoder was soldered to the cathode of the
front LED, the brown/red wire to the anode of the rear LED.
A 680 Ohm resistor was soldered between the rear cathode and the front anode.
Photo from Märklin 3044, Henshel EA 800
Front and rear light:
The 28452 locomotive had a 610040 bulb in each end, in bulb sockets. I
replaced these with bulbs 610080, to cope with the higher voltage from the 60760
decoder.
I kept the original wires soldered to the sockets, as it's not so easy to access
the bulb socket from below with a soldering iron.
The wires were soldered directly to the decoder.
This photo shows the new front lamp:
Anti Alzheimer:
The 60760 decoder was known for one "bad" thing; to forgets it's previous speed,
even after a short power loss, and restarts the acceleration from zero.
This is often referred to as the 60760 Alzheimer effect. his may have been
early production only, as I have only experienced the phenomena on one very
early (2005) production decoder.
To avoid this, make a "back-up" power supply, which gives a short time
power supply to the memory circuit in the decoder. I installed a small
capacitor and a resistor, connected to the decoder.
See above photo and below wiring diagram.
It is installed in this locomotive as a precaution and for fun, as I had the parts laying around.
The 60760 decoder:
This photo shows the 60760 decoder, with some additional wiring.
On top:
no. 3 from right - a brown/red wire for the "secret" f3 output, used
for the interior light
no. 4 from right - an additional orange wire, with + for the functions
On the bottom:
A purple wire to the minus end of the capacitor
A black wire to the resistor.
I see from the detailed photo that some of the soldering must be re-done.
Wiring diagram for the 28452 locomotive:
Part list for the conversion:
Part number | Pcs. | Description | |
---|---|---|---|
60760 | 1 | Conversion set for locomotives with 5-pole drum collector motor | |
456200 | 1 | Holder for decoder | |
610080 | 2 | Bulbs (22 Volt) | |
- | 2 | smd LED, yellow | For the interior light |
- | 1 | 680 Ohm resistor | |
- | 1 | 10 Kohm resistor | For the "Anti Alzheimer" circuit board |
- | 1 | 1000 uF 6,3 Volt capacitor | |
- | 1 | Home made experimental circuit board, 3 rows, 6 holes |
Screenshot from Central Station 1:
Märklin 28452 Henschel DH 360 in the dark:
Some external links:
http://de.wikipedia.org/wiki/Henschel_DH_360
Rangierdiesel.de obout DH 360