DCC Conversions for British H0: Diesel and Electric
First posted early August 2018; revised along the way as I make progress. Most recent changes on 25 November 2018.
Roco NS 600 (DCC-ready version) .. 1 August 2018, reworked 7 September 2018
Halling Flexity tram .. 10 August 2018
Mehano Class 66 .. 12 August, 24 August and 11 October 2018
Fleischmann Warship .. 16 August 2018
AL-07 8 Pin DCC Socket .. 23 August 2018
Lesney Matchbox MB-24 .. 24 August 2018
Lima Class 33 .. 11 September 2018
REE Moyse Locotracteur .. 29 September 2018
NMJ MaK Di8 .. 2 and 11 October 2018
Life-Like Proto 2000 chassis (for Lima class 33 conversions) .. 3 October 2018
Here are details of how I have gone about converting my engines and other prime movers to DCC. I do not claim to have done the work the best way, but I am trying to keep the installations neat and tidy. The models run, with limitations noted. Some run better than others - my initial impression is a cheap decoder in a good model with a heavy flywheel can work well, and similarly a better quality decoder can bring out the best of a cheap motor ... but the combination of cheap decoder with cheap motor is best avoided. The single most useful configuration option seems to be to disable support for analogue operation (CV #29 bit 2), this improves slow running for everything.
Roco NS600 (DCC-ready version)
It seems sensible to begin with something "DCC ready" and the later versions of the Roco 350hp English Electric shunter come with an 8-pin DCC socket in the cab. This model converts easily into a BR class 11. I settled on the Gaugemaster p/n DCC22 "very small locomotive decoder", partly because I was confident it would fit and also, if I find a better solution for this engine, I am sure I can use this decoder in other models.
The first generation models (identifiable by moulded cab hand rails and a body fixing screw on the top of the bonnet) have direct connections by metal strips between the pickups and motor will be more difficult to convert to DCC.
The superstructure of the Roco shunter splits horizontally at the footplate. To get access to the DCC socket you need to pull off the radiator grill and then lift off the upper part of the body. You don't need to disturb any of the screws under the chassis. The upper part of the body is a very tight fit on my model.
The engine runs nicely, and the head and tail lights are available on function key 0.
I cannot find any mark for pin 1 on the pcb in the engine. If you plug the decoder in the wrong way round, the engine runs fine (with the default forward and reverse directions transposed) but the lights will not work.
I lived with the Gaugemaster decoder for about a month before swapping it out for a Lenz Standard+ V2. The Lenz decoder offers far better motor control including six pre-set motor profiles and a low-speed shunting mode. It is also rather harder to squeeze into the space available here, but there is just enough room to coil up the wiring harness.
The Lenz Standard+ V2 takes up the space for the shroud inside the windows so I would have to obscure the insides of the cab windows with paint or thin card.
About three months after this, I swapped the Lenz Standard+ V2 out for a Lenz Silver+. The Silver+ is from the previous Lenz range and it has the advantage of being about 3 mm shorter. This leaves enough space to install the window shroud.
Both these Lenz decoders have their components on only one side of the pcb, so there is a large flat area to attach the decoder to the model. I used the double-sided pads supplied with the decoders.
Halling Bombardier 'Flexity' tram
The 2018 release of the Halling Flexity is DCC-ready with a socket and some lights; the older models are not. My conversion is on one of the older models.
I found two conflicting ideals for the conversion: to put the decoder somewhere to minimise the number of flexing wires, and to put the decoder out of sight. The whole of the interior is very visible and there is no space to hide a decoder in the middle section except under the roof, and this is occupied by a ballast weight. I did look into cutting away part of the interior moulding and adding a styrene box and some passengers to hide the decoder, but this seemed a bit intrusive. The model cost quite a lot of money and if I ever sell it on, the buyer might want to revert to analogue operation.
There is a space to hide a decoder inside the floor beside the motor bogie, and this has worked out for me. It is quite straightforward to dismantle the model but there is only really one possible sequence:
1. Remove the body on the middle section. To do this, spread the lower edges of the body moulding and lift off the body.
2. Remove the two adjacent body mouldings the same way. The bodies of the two cab sections remain in place.
3. Lift out the interior moulding on the middle section.
4. Prise out the interior moulding on the section beside the motor.
Cut off the motor suppression capacitor (the wires are crimped as well as soldered) and unsolder the wires from the motor. Unsolder the same wires from the pick-ups on the middle section. The rest of the original wiring remains unaltered.
I used the Gaugemaster DCC22 "very small locomotive decoder" because it fits into the space available and the one I put into the Roco NS600 works well. I cut off the three wires for the decoder functions (white, yellow and blue) because there is nowhere to coil them up, and then cut off the 8-pin header. I glued in two pieces of a copperclad sleeper to connect the wiring for the pick-ups, and then hard-wired the decoder into place:
I reused most of the original wiring here, but the two wires from the copperclad strips to the middle section are new. I looped these up onto the sides of the motor to try to maximise flexibility. I secured all of the wires with dabs of superglue so the soldered joints are not stressed during running.
Reassembly is easier than dismantling, this is a first for me. The decoder is clamped into place by the interior moulding above it. The most important thing is to make sure all of the wiring is routed correctly through the articulated joints and behind the powered wheels, and does not get trapped or rubbed when the model runs along the track.
I would prefer a socketed installation, but after buying an 8-way socket with a small wiring loom, I could not see anywhere to neatly fix it onto the model without making major alterations. Performance with the DCC22 decoder is a bit frantic and I suspect I can spend a great deal of time fiddling with CV values. However for the time being, the tram is now suitable for DCC operation, and the conversion is nicely hidden away from view.
Mehano Class 66
The Mehano class 66 has a 21-pin socket. To get access to the socket, turn the model upside-down and remove the four cross-headed screws above the inner ends of the bogies. Then lift off the body shell.
I bought my model second-hand, and it arrived without any instructions. To begin with I dropped in a Gaugemaster DCC27 'Omni' decoder, this was reasonably-priced and available in the local model shop. The control of the motor was exemplary, but the lights did not work correctly. The Omni is a four-function decoder ... I spoke to Gaugemaster and they suggested, with so many lights at each end, perhaps the model needs a six-function version. There are no detailed instructions available from Gaugemaster for their DCC27, and so I tried a Dapol Imperium1 (they had one in stock), this is a six function decoder:
The motor control is as good as with the Omni, and I can now switch all of the headlights on and off using F1 and F4 at one end and F2 and F3 at the other end. F0 ("headlight") turns on the tail lamps with directional control, although much of the light shines out through the yellow warning panel of the loco near the centre.
I have spent a few hours trying to remap the decoder outputs to different function keys and achieved nothing of use. And so, I have learnt my first big lesson with DCC. Some manufacturers do not supply programming information for their decoders, either in the package or as a download, and this seems to be the case with Dapol and their Imperium1 as well as the Gaugemaster with their DCC27. Nothing more than a list of CVs. I have tried instructions for TCS decoders, instructions for Lenz decoders and the function mapping feature of the PowerCab.
I am facing up to multiple interpretations of the 21-pin interface (NMRA and NEM), a model built to produce lighting arrangements used in mainland Europe, and a decoder with no instructions. All I want is the three headlamps at each end to come on with the direction of travel (F0), and a separate control of the red tail lamps so they can be on or off depending on whether the engine is pulling a train.
I have considered a couple of hardware options. One (which I would prefer) is to connect a wired decoder to the applicable pins on the 21-pin header. Four functions would be enough to do this: two functions for two sets of headlights, and two functions for the tail lights. This would leave the model unmodified, which would be good if I ever wanted to go for a sound option. But I wish the connectors were not so tiny.
The other method (which I have done) is to modify the wiring in the engine. This moves the wiring from the pcb pads which don't work as wanted to the ones which do. I suppose, the ethos of rewiring a Continental model for use in Great Britain is no different to changing the paint on the body shell.
The function outputs from the decoder appear at a block of eight solder pads on the pcb:
1. Identify the two wires connected to the pads labelled V+ and leave these undisturbed.
2. Unsolder the six wires from the pads labelled A, B and C.
3. With the engine powered up on the track, touch each of these six wires against the chassis block and identify the two wires for the tail lamps, one wire for each end. I marked these wires with red paint.
4. Similarly identify the wires for the four headlamp circuits (two wires for each end) and connect these together in pairs.
Using the Imperium1 in its factory state and looking at the model in the same orientation as the photos, the six solder pads work like this:
F1 ..... F0r ..... F4
A ........ B ........ C
F2 ..... F0f ..... F3
5. I chose to leave F1 and F2 unused. So I soldered the two pairs of headlamp wires onto 'B' and the two tail lamp wires onto 'C'. This is not fun, indeed it is not 'hobby' to me - it is an absolute pain to do. The wires are barely long enough and having black wires on a black pcb makes it worse. One pair of headlamp wires was a few millimetres too short so I put in the grey link wire.
So I now have directional headlamps on F0 (and the 'headlamp' button on the controller); and manually-selectable tail lamps on F3 and F4. I am glad, this is my only DCC-ready engine with a 21-pin interface. The remaining 'modern' models use PluX or a 6-pin arrangement.
The list of CVs for the Imperium1 suggests compliance with the TCS approach to function mapping, although the actual behaviour is different. So I have probably made life difficult for myself by buying a broadly 'USA-style' decoder for a European model. But it is quite shocking to compare the level of product information provided by Dapol with that of an equivalent product from another model train manufacturer like (say) Roco. I am not going to write down a blacklist of rubbish decoders, but I have a list forming in my mind.After
A couple of months on, I swapped out the Imperium for an ESU LokPilot V4.0. This gives hugely better low-speed control over either of the first two decoders, and has four accessory outputs as well as the six function outputs. It comes with an 80-page instruction book, all in German so maybe I will remember some of my O-level German. The decoder seems to give excellent performance with its factory settings, and I wish I had started with one of these - I could probably have saved myself all of the rewiring.
The Fleischmann Warship dates from the 1970s and has a live chassis for the engine and a live block for the motor bogie. I put a set of Ultrascale wheels on my model a couple of years ago, and this write-up is very much for an engine with all of its wheels similarly insulated from their axles and from the block of the motor bogie.
1. Remove the body shell (two self-tapping screws below the fuel tanks) and, if they are not already done, fit a set of all-insulated wheels. Use washers or shims to make sure the metal parts of the wheels cannot touch the block of the motor bogie.
2. Remove all of the original wiring. I kept the short length of black wire attached to the pick-ups on the motor bogie because this was easier than soldering on a complete new wire, but everything else went.
3. The chassis of the engine is now isolated electrically from everything else.
4. Remove and discard the original lighting units. If I ever add lights I will use LEDs.
5. On the motor bogie, remove the inductor and the capacitor. The capacitor on my model was a solid cylinder placed across the two motor brush terminals, and I removed it with a cut-off disc in a mini-drill. I also cut off the tag of the third terminal, which now served no purpose.
This completes the destruction, but some modellers may want to go further with the motor bogie - see later.
8. Connect the red and black wires to the pick-ups on the trailing bogie. The black wire goes to the same side as the motor gear train. Connect a fresh red wire to link the pick-ups on the trailing bogie to those on the terminals side of the motor bogie.
9. Connect the orange and grey wires to the two motor terminals. If you connect the orange wire to the left terminal then the engine will run 'forwards' with the crew at the front and the motor bogie at the back:
This completes the new wiring for DCC operation. It is sensible to look for possible short circuits before plugging in the decoder.
The chassis block of the motor bogie is permanently connected to one of the brushes, but on inspection this chassis block cannot now physically touch a live rail unless (a.) it is touching the chassis of the whole engine and (b.) at least one wheel of the trailing bogie is touching the chassis as well and (c.) the engine is still on the track. As far as I can see, this cannot happen on my layout, and I consider the installation to be robust for use for me. Different wheels on layouts with very sharp curves may cause problems, and if this seems likely you will need to look into isolating the motor brush from the block of the motor bogie.
My conversion has removed the current collection from the two wheels on side of the motor bogie with the gears, and so my engine has pick-ups on six wheels not eight. There is hardly any space here to install new electrical pick-ups, and with DCC in the model it looks a lot easier to fit a stay alive unit instead.
I added a small platform from styrene to hold the decoder, and fixed the decoder onto this with double-sided sticky foam:
I am using a Lenz Standard+ V2 decoder. The engine always ran well on an analogue controller, and performance with this decoder is even better.
At this point I learnt my second important lesson with DCC. I swapped out the Lenz decoder to try the Gaugemaster 'Omni' released from my Mehano class 66. The performance of the Warship went from wonderful to appalling, and so I swapped the Lenz back in again. The Omni worked fine with the 2010s motor in the class 66, but barely at all with the 1970s motor in the Warship.
AL-07 8 Pin DCC Socket
The solder pads are large enough to attach more than one wire, and this would be useful for multiple pick-ups or the two common wires needed for head and tail lamps. Conversely there is no need to coil up or cut off any wires you are not using. The pcb is actually double-sided and the socket terminals protrude out of the underside - so installation still needs a base of insulating material. The ones I bought are called a "AL-07 8 Pin DCC Socket" and I bought mine through a seller on eBay.
Lesney Matchbox MB-24
I motorised my MB-24 with the chassis from the Underground Ernie inspection car by Bachmann. This chassis has uses for 1:76 and 1:43 scales as well as 1:87 so I have posted the details as a topic in the DCC section.
Lima Class 33
By today's standards, the Lima class 33 is more like a toy than a model, but it does have an old-fashioned simplicity which makes a conversion to DCC straightforward to do. My model is a fairly tidy and unworn specimen, but it now actually runs better than it did with an analogue controller.
I used the Lenz Standard+ V2 decoder because it works well with the pancake motor in my Fleischmann Warship.
1. Open out the bottom edges of the body shell where they clip onto the chassis and lift off the body shell.
2. Lift out the ballast weight.
3. Remove all of the existing wiring. There is no need to take the motor bogie out of the chassis, but it is easier to unsolder the wire to its pick-up if you undo the two screws underneath it and remove the moulding for the bogie side frames. My model did not have any suppression capacitors, but take these out if there are any present.
I assume the motor bogie is at the trailing end of the model, mainly because my Fleischmann Warship seems to haul trains up my 1:20 gradients better with the motor at the back.
4. Solder a red wire to the pick-up on the motor bogie and replace the moulding for the bogie side frames.
There is plenty of space for a socket and a decoder. I used one of the 'AL-07' 8-pin sockets for the model, with the socket glued down onto slips of strip wood to lift its socket pins clear of the chassis.
The blob of Blu Tack here is important, it stops the electrical contact for the trailing bogie touching something it should not, especially the connections to the motor.
The model runs really well with the default settings in the Lenz decoder. The built-in slow running feature (F3) makes this even better. I have experimented with CVs 5 and 6 as well, but this tends to make controllability different rather than better.
This conversion was a bit of surprise. I began with fitting a socket because somehow I expected to be putting in a blanking plug and returning the engine to analogue operation, but really the performance is pretty good. It would be better with some more pick-ups, and there is space to add some working headlights too. So a rebuild could be a future project in its own right.
REE Moyse Locotracteur
The Moyse Locotracteur is close to British outline and I have one on my layout, but I have no evidence of a prototype being used in Britain. So it would be wrong to call the model British H0, and I have posted the details of the DCC conversion in the topic for the model, located in the French railways section.
NMJ MaK Di8
The NMJ model of the Maschinenbau Kiel (MaK) Di8 comes with a 21-pin MTC socket fitted with a large blanking plug. So far I have had to buy only two 21-pin decoders and I am not particularly happy with either. This is mainly because as a beginner to DCC I chose decoders with what turned out to be no meaningful manufacturer support - the Gaugemaster 'Omni' and the Dapol 'Imperium'.
The Gaugemaster 'Omni' was in my spares box and the Di8 looks like a way to used this up. This is a four-function decoder, and it gives directional head and tail lights on F0, and the banks of nose floodlights on F1 and F2. There was no instruction book with the model and I don't know if there is any more functionality to be had. The tail lights are wired to the same circuits as the headlights, so there is no option to turn off the tail lights when the engine is pulling a train.
The model comes with a leaflet explaining how to fit a decoder and detail parts but the description is simplified.
1. Grasp the cab by its flat sides and pull it upwards off the model.
2. Ease the bonnet moulding upwards and off the model. The footplate remains in place.
3. Reassembly requires care. The bonnet moulding is easy to install, but mouldings of steps on the cab can catch against the handrails on the footplate. In fact, one of the handrails had been trapped here during the factory build. It seems best to ease the cab slowly into place, watching all four handrails. They are made from a flexible plastic, perhaps a rigid polythene, and mine bounced back into shape without problems.
There is a modest amount of free space near the DCC socket, and it is possible to squeeze in a 21 to 8-pin adaptor, and an 8-pin decoder on a loom. However, when I tried this none of the lights would work. Alternatively, there is scope to modify the wiring of the model to use a 6-function decoder and add independent switching of the tail lamps.
The low speed performance of the model was nowhere ear as good as I expected for a model of this calibre or what I expected for a shunter, and I swapped out the Gaugemaster 'Omni' for an ESU LokPilot V4.0 after ten days. This seems to control the model perfectly using the factory settings, but sadly I did not find any extra lights to light up.
I think the best place for the Omni is in a model to sell on as "DCC fitted". Barely two months after starting my DCC conversions I fear I have become a DCC snob.
Life-Like Proto 2000 chassis (for Lima class 33 conversions)
The Life-Like Proto 2000 model of the US type FA locomotive is not British H0, but its chassis is commendably compact and fits into the body shell of the Lima class 33. So this chassis is usable for models of the BR classes 26, 27 and 33 derived from the Lima model. I tried to find a space to install a DCC socket, but the only places I could find were the cabs. The lower parts of the cabs are consumed by the worm gear housings, so this meant behind the windows in full view from outside. I settled on a hard-wired installation of a Lenz Standard+ V2, with the decoder attached to one side of the motor.
This procedure assumes you have stripped out the fan mechanism and the cab details to make the chassis suitable for British outline:
1. Remove all of the original wiring.
2. Modify the decoder by removing the white, yellow, green, and blue wires. This makes for a tidier installation.
3. Attach the decoder to one side of the motor, with the lower edge of the decoder just above the chassis. I used the double-sided pad supplied with the Lenz decoder.
4. Solder the orange wire to the top contact on the motor.
5. Lift out the motor complete with its rubber mounting bushes, pulling the drive shaft off both universal joints as the motor comes away.
6. Solder the grey wire to the bottom contact on the motor.
7. In theory, the bottom contact on the motor cannot quite touch the chassis, but I added a strip of insulating tape along the length of the contact to make sure.
8. Re-install the motor, reconnecting both universal joints.
9. Solder the black wire to one of the bogie terminals.
10. Solder a fresh length of wire between the terminals on the two bogies.
11. Connect the red wire to the chassis. I used a short length of a wooden cocktail stick to jam the wire into one of the unused holes.
12. Add cable ties to make sure the wires do not get trapped when you install the body shell.
See also: DCC Conversions for British H0: Steam