I have finished the decoder install so I have done a write-up.
Digitizing LGB 28001 Rugen 0-8-0T
The loco as shipped is “DCC ready” in that it has the 4 pins exposed for track and motor, onto which you can plug a Massoth L or LS in this case, and a 6 pin socket for lights and smoke.
To install a decoder, you have to disassemble the loco. I used the exploded parts diagram referenced in an earlier posting as a guide. The page numbers listed below reference that document. Remove the boiler front (#17) and unplug the front lights and smoke generator wiring. You don’t have to do this but I also removed all the piping, levers, dome covers, chimney, bell and whistle so they wouldn’t get damaged in the dismantling process.
There are eight screws labelled K, L, M, N O, P, Q and R on page 3 and two more screws securing the front of the boiler labelled I on page 2. The trick to finally remove the body from the chassis is to prise out the pieces #51 and #52 (regulator arm pivots I think) and ease out the regulator rods (labelled S and T on page 4). Now the combined cab and boiler should lift off. There will still be some wiring connecting them which is the 4 wire harness connecting the circuit board to the motor block. Unplug either end of that cable and you should be able to separate the cab and boiler from the chassis. Beware that the cab weight may fall out at this point!
Now you can separate the cab from the boiler. The trick here is to ease the cab sides apart slightly or squeeze the boiler surround to release a notch in the cab surround, see pictures below. There is a 5 strand cable for the rear lights, cab light and multi-function socket, connecting the cab to the circuit board inside the boiler, and a 4 strand cable for the 4 way switch. There are some more screws under the boiler to release the boiler from the black footplate and release the weight inside the boiler. That weight is heavy, do not let it fall! You can then unplug the 5 strand cable and 4 way switch cable from the circuit board and separate the cab from the boiler.
I removed the circuit board, see picture below. You can connect a Massoth L or LS decoder to the 4 motor/track pins and the lighting circuits to the 6 pin socket provided on the circuit board but I decided to wire up the LS decoder directly. I did reuse the 8 pins and the end of the circuit and the 5 pin socket by cutting them out of the board, shown on the picture below. This was so I could leave all the lighting and smoke generator wiring in place.
I installed a 57mm circular 8 ohm speaker behind the firebox speaker grill provided. I fitted a Massoth firebox glow LED light fitting behind the hole left by the 4 way switch which was no longer required. Slightly odd place but the speaker prevents you installing it in the “proper” place. I used the lighting and function cables provided with the Massoth L and soldered the ends of those to the bits of circuit board I had recovered from the main board. I also fitted a Massoth volume control under the steam dome, held in place with black tack.
The rear lights, multi-function socket and cab light were connected to the decoder light socket, with the multi-function socket using the front light connection. The 5 wires on the plug from the cab are (from left to right) cab -, lamps -, +, and + and – for the multi-function socket. The two + were connected together (so the 5 wires became 4) and then connected to the 4 socket lighting plug on the Massoth LS decoder. The front lights were connected to function output A4 (set by function key 0 forward only), the smoke generator to function output A1 (function key 7), and firebox light to A3 (function key 4). The default voltage output is full track voltage so it is very important to reduce this 5v (value 5) in the decoder settings before you use the lights or smoke generator!
Before I reassembled everything I tested the chassis / motor with the decoder, see picture below. You need to place the weights in position otherwise the chassis tips up without them.
I sawed off the driver figure after this picture, it was impossible to remove otherwise. Reassemble the loco in the reverse of the instructions above. I secured the decoder to the boiler weight using the 2 sided padded tape provided with the LS and then slid the weight into the boiler and secured with a screw. As Jon said it is a bit of a pig getting the wires inside without being trapped, especially with the speaker in the way, and not letting the cab weight fall out, but I’ve had worse to do.
In terms of decoder settings I did not have to change much from the default basic settings apart from the voltage for the lighting and function outputs. This model definitely needs back EMF (or PI Load Control as Massoth call it) especially if you try and start the loco on an R1 curve, due to the friction on the four axles. The default PI Load Control settings seem to be okay and give a smooth if slow start from standstill.
For lighting I used standard F0 for directional light, which also switches on the cab light and multi-function socket power (forward only). I set F4 for the firebox light which I also used for coal shovelling sound, see below.
The Massoth LS sound was of a basic steam loco (dampflok). The sounds provided in slots 1-12 are listed below and I have shown the function keys I have assigned them to.
1 long whistle F1
2 brake sound (automatic)
3 three short whistles (Zp 3) F8
4 conductor whistle “all aboard” F3
5 air pump (fast) F9
6 generator F10
7 water pump F11
8 coal shovelling F4
9 “tickets please” F13
10 air pump (slow) F14
11 bell F2
12 start whistle (automatic)
F5 is used to turn side cylinder noise on/off and F6 to turn sound on/off. F7 is used for the smoke generator and F8 for switching /shunting speed, which also sounds the three short whistle signal.
Once assembled and tested I added a few cosmetic touches. I replaced the “brass” lamp rings with black ones (from modell-land) and painted the bell, whistle and valve wheels matt black. I painted the air brake pipe surrounds red, and the cab steps black. For some reason LGB paint the yellow electrical junction box panels on the cab end but not the front end, so I painted those. Small touches but I think it helps.
Here is the model compared to the prototype. I might try painting the wheel rims red and weathering the shiny valve gear and coupling rods at a later date.
