Improving the Vitrains lighting, fitted to the Northern Belle Class 47 locos from Rail Exclusive and some minor reprogramming of the Zimo sound decoders to handle the updated lighting.




The Rail Exclusive Northern Belle Class 47 pair has at last arrived, with its newly tooled bodywork and up to date grills! (Hornby Northern Belle coaching stock is now also safely in place awaiting this superior motive power! ) ..... but well known shortcomings in Vitrains Class 47 lighting arrangements will need to be addressed before the locos are commissioned. I'll also add drivers and their cab lights plus a detonator flash LED on the lead wheel of the consist.

I've also gone for the comprehensive supporting Paul Chetter sound project equipped Zimo decoder package. Although Jamie kindly sent me an early function mapping summary, now I've received my units (19 Jan 2015) quite a lot has changed, so I'll have to rethink my original mapping ideas.



A quick assessment of the new Vitrains 47 lighting on the first unit, 47990 "Galloway Princess":

Vitrains have corrected their over-bright front markers by the simple expedient of omitting the original light pipes that terminated in the marker lenses. The headlight is still not very bright, but at least its now brighter than the markers.  The rear lights are still rather dim!

I think its worth some mods as these are excellent models and deserve to have better lighting. I'll try a white LED directly behind the headlight lens in the upper body shell this time and a repeat of the previous rear light update on the chassis.

The cab interior is badly represented due to the way the lights have been done. The floor level is somewhere near the driver's chest!  Unfortunately, the cab light may make this more obvious!

The front plastic is still not light proof, so a coat of opaque paint on the front of the cab assembly and around the lens apertures on the inside of the upper body shell is prudent. (With great care not to get any on the new flat marker light lenses!)


Both DRS Northern Belle liveried Class 47s, Galloway Princess and Solway Princess are included.


The Vitrains lighting system:     

What's wrong with the factory solution?  Well to be honest, with the original marker lightpipes removed, the forward lighting is not half bad (when viewed in daylight) although the headlights are a bit on the dim side, however, the rear lights are so dim they can barely be seen in daylight. There is quite a lot of light leakage from the plastics surrounding each lighting lens and in darkness, there is serious coupling of the red rear lights into the forward lighting. The unit comes wired with directional lights active at both ends and no means to disable lighting at one end.  So, plenty of scope for improvements! I came across a magazine article recently, describing a total replacement of the lighting with a newly fabricated pcb fitted with chip LEDs and mounted on the inside of the upper body shell. This looks a good solution, but its a lot of work. I have a somewhat simpler solution in mind, based on some experiments with a friend's Vitrains 47 a couple of years ago.

The Vitrain light sources are two 3mm leaded LEDs, one red & one white, positioned vertically at each end of the chassis assembly. These illuminate light pipe mouldings, mounted below the internal cab moulding. The light pipes terminate in flush lighting lenses that penetrate the front & rear of the upper body shell. (Except for the new front markers which now have no light pipes and simply use flat lenses in the outer body shell.)

The underside of the cab moulding, showing the new light pipe network: The white and red LEDs on the chassis assembly locate on the centre line within each light pipe enclosure...... when the two body halves are together.

(Earlier Vitrain 47s also had additional light pipes to each marker light lens in the front enclosure.)

The Red LED is too far from the light pipe inputs as the level of red light radiated outwards from its sides is quite low.  The white LED is close enough to the marker lights not to need light pipes. The light pipe feeding the headlight is not correctly aligned with the white LED and probably needs rather more light to overcome losses. These problems are compounded by a lack of protective opaque coating on the upper body shell, where the lenses pass through, resulting in light bleed from the surrounding plastics.


The Proposed fixes to the lighting system:

The first task is to extract each cab assembly from the upper body shell and carefully apply matt black paint around the periphery of the holes through which the light pipe lenses are located, on the inside of the upper body shell and around the inner surface of the holes. This should eliminate light bleed through the case plastics.   (I didn't dare go too near the marker lenses with the paint..... time will tell if I have to go closer!)

The upper body shell with the cab assembly removed, showing the black paint application.

The inside of the cab roof is painted white and a white LED is fitted.


Matt black paint applied to the front & top of the cab assembly.

The headlight light pipe has been removed at this stage and its fixing hole is filled and over-painted.

A very truncated Noch driver is now at the (rather sparse) controls.


Adding a Cab Light & Driver: A cut down Noch driver is added to the front cab (speaker end) of each loco. The cab roof is painted white & when dry, a white chip LED running circa 5mA is glued to the centre of the cab roof. This will be wired via its series resistor back to the decoder where the positive will go to common positive and the negative to FO3.

A Brighter headlight: An additional daylight white pre-wired nanolight chip LED is glued to the rear of the headlight lens after the associated light pipe has been separated from it. The positive supply shares the positive to the cab light and the second headlight at the other end of the loco. The negative is routed via a series resistor, to the decoder.

Showing how the headlight lightpipe is removed, with a sharp craft knife, to leave a flat surface for the LED

Showing the headlight modifications

A rather grainy close up, showing the chip LED glued to the rear of the lens


Rear Lights: To improve the rear light intensity, two new "signal red" pre-wired nanolight chip LEDs are fitted on plasticard mounts super glued to the lighting PCB on either side of the original red LED. The new chip LEDs are positioned so that when the loco is assembled, they beam directly into the inputs of the pink light pipe attached to the underside of the cab assembly. (The same modifications are eventually carried out at both ends of the chassis assembly.)  ...... However please read on, as after trying a different approach on the second locomotive, I eventually remounted the new red LEDs close to the light pipe input faces in the upper body shell.

The 2 new red chip LEDs are connected in series

The chip LEDs replace the original red LED, but run at 1/3 original current


See also: the shields I had to fit to keep the red lights out of the markers & headlight for night running (shield photo after first unit testing comments below).


Forward lights (brighter headlight than Vitrains)

Rear lights (deliberately kept prototypically dim, but at least unlike Vitrains, you can see these in daylight!)


Cab light (Vitrains do not provide one)

The lights can be set independently at each end of the locomotive, so for example, the lead locomotive can have only its front lights active, while a locomotive at the rear of the train can have only its back lighting active.

If the train is reversed, the same outer lights remain on but forward lights change to rear and rear to forward.


Detonator Flash LED:

I'll fit a white chip LED beside the leading wheel on the right hand side, ready to be synchronised with the detonator sound. The detail will have to wait until I study the bogie structure, but I'll assume that the series resistor will be 1k and wiring will be via decoder FO4.


A different approach to the second 47 Lighting:

Further down the page is a brief account of test findings and the fixes applied to the first loco.  A key problem was rear light glow leaking into the headlight and marker lights, visible in the dark. Its difficult to deal with as the marker light source and rear light source are both in the chassis unit, while the lenses and light pipes are in the upper body shell. So sealing one from the other is not easy.

For 47 number two, I'm going to fit the new rear light and new marker light sources (plus new headlight as before) in the upper body shell (removing the original LEDs completely). Sealing of red from white should then be much simpler! The wiring is also simplified, as only motor and track contact connections need to go to the chassis (plus 2 wires for a detonator flash LED if fitted to the second unit).  I'll also apply opaque black paint to the inside of the cab roof, before painting it white, to prevent light leakage there.




The Northern Belle didn't always have dedicated matching Class 47 locos!  (Running through Ely in 2009)



Modifying the wiring of the main PCB:  

Original Lighting Circuit


Modified Circuit Arrangement for the first loco with updated lighting and sound decoder (Detonator Flash LED now fitted to second loco only)


Top view of Zimo MX645 showing the pad locations for FO6 and FO4 (easiest pads to access under the sleeve).


Main PCB, with cuts marked & decoder FO2 (brown) wire termination point indicated.



Atmospheric shot of the Belle in motion from the Northern Belle Website.


Programming Updates:

My advanced information was somewhat different to the definitive function list that is included with the units..... no doubt partially because of Paul's new driving arrangements.

Here is the new list:

The Zimo MX645 function mapping list that arrived with the locos
F0 Master lights switch F15 Scavenger Fans (also a random sound)
F1 Sound on/off Engine start / shut-down F16 Platform Announcement
F2 Brake application F17 Despatch Whistle
F3 Playable Low Horn F18 Spirax Valves
F4 Playable High Horn F19 Fade-Out of sounds (3 sec)
F5 Light Engine mode (and "cold start" trigger) F20 Shunting Mode (Half Speed, Zero Inertia)
F6 Coast/Idle button F21 Lighting adjust
F7 Full Power button F22 Cab Sound: DSD vigilance warble
F8 On/Off Buffering-up/Coupling thrown over hook F23 Cab Sound: AWS Warning
F9 Flange Squeal (variable length) F24 Detonators exploding (decelerating)
F10 Brake (Air) Release F25 General Station Ambience
F11 Two tone horn F26 Platform Announcement (some versions only)
F12 Driver's door open (on) / close (off) F27 Live Volume control Down
F13 Driver's Pre-start checks (on) / Post start checks (off) F28 Live Volume control Up
F14 Triple Pump Starts & Runs (on) / Stops (off)    

For my lighting control:

..... I need five button assignments:  With so much content, I'm going to have to remove some functions to make room for the lights switching:

                                          I'm going to remove the following: Shunting Mode, Fade out of sounds and the scavenger fan button controlled sound (the automatic random sound remains in place).

Because the Zimo hardware function mapping is limited to keys 0 to 12*, I'm going to have to move two sound functions from this key range, to the higher number keys freed up by my deletions.

(*Unless using Swiss Mapping)

Light engine running lights Enable F0:  Forward FO1 + FO(H/L),  Reverse FO(Rear) + FO2   (See Swiss Mapping Details below).

Front lights only (Swiss mapping, see below) Fwd FO1 Rev FO2 via F20 (Delete Shunting Mode from F20)......  Disable shunting mode/zero momentum via CV124 bits 0-4 & 6 and CVs 155 & 156 which define F keys.

Rear lights only (Swiss mapping, see below) Fwd FO(H/L) Rev FO(Rear) F21

Cab light F10  FO6 (F19 fade-out delete; Remap Brake (Air) Release from F10 to F19)   CV313 to zero to remove mute, 

                     To move F10 sound to F19,  move CVs 540,541,542 content to CVs 567,568,569 & set CVs 540,541,542 to zero.      Then CV61=97, CV44=128 to assign FO6 to F10.

Detonator flash LED  F11  FO4 (F15 scavenger fans delete; Remap Two tone horn from F11 to F15)  Move CVs 543,544,545 content to CVs 555,556,557 & set CVs 543,544,545 to zero.

                                                                                                                                                     Then CV61=97, CV45=32 to assign FO4 to F11.

Set CV127 to zero and set CV132 to 60. (See below for explanation.)

Swiss mapping for the running lights:

Description CV Number Value
Set Button F0 (forward) function outputs for light engine:      FO1 + F(H/L) 33 5
Set Button F0 (reverse) function outputs for light engine       FO(R/L) + FO2 34 10
Set End 1 lights only (Swiss mapping with F0 also on) via F20 430 20
  431 157
A1 FO1 432 1
  433 0
A2 FO2 434 2
  435 0
Set End 2 lights only (Swiss mapping with F0 also on) via F21 436 21
  437 157
A1 F0(fwd) 438 14
  439 0
A2 F0(rev) 440 15
  441 0


Resulting Function Mapping Chart

The Final Zimo MX645 function mapping list
F0 Light engine running lights
F1 Sound on/off Engine start / shut-down
F2 Brake application
F3 Playable Low Horn
F4 Playable High Horn
F5 Light Engine mode (and "cold start" trigger)
F6 Coast/Idle button
F7 Full Power button
F8 On/Off Buffering-up/Coupling thrown over hook
F9 Flange Squeal (variable length)
F10 Forward end Cab light
F11 Detonator flash LED (47832 only)
F12 Driver's door open (on) / close (off)
F13 Driver's Pre-start checks (on) / Post start checks (off)
F14 Triple Pump Starts & Runs (on) / Stops (off)
F15 Two tone horn
F16 Platform Announcement
F17 Despatch Whistle
F18 Spirax Valves
F19 Brake (Air) Release
F20 (Plus F0) Forward end lights only
F21 (Plus F0) Rear end lights only
F22 Cab Sound: DSD vigilance warble
F23 Cab Sound: AWS Warning
F24 Detonators exploding (decelerating)
F25 General Station Ambience
F26 Platform Announcement (some versions only)
F27 Live Volume control Down
F28 Live Volume control Up


Testing The First Unit:

All looked fine until the locomotive moved off, when the forward lights (on FO1) extinguished, only to reappear when the loco stopped again....... Interesting effect, but not entirely helpful!..... but a quick read of the "Special Effects For Function Outputs" (Manual section 3.22) Revealed the explanation, CV127 was set to 60, which produces exactly this effect.

I'm guessing that Paul may have intended FO1 to be used for the cab light, in which case it would have been a useful attribute..... so much so, that I'll set CV132 to 60 to produce the same effect on my cab light, which runs from FO6!

Have increased the series resistor value for the 3k9 they are probably still a bit over-bright, so I'll drop the current a bit further.

Night time testing has revealed a couple of additional issues: With just the rear lights on, there is a red glow from the marker lights and headlight, despite a small dividing wall I've already installed to address the issue.      Also, there is a small amount of light bleed through the roof with the cab light on. Better sort this lot out before moving on to loco number 2!

Headlight LED series resistor value now down to 6k8. Looks more believable if somewhat less impressive! Cab light LED current halved (now 4k7 series resistor) still a hint of light bleed through the roof, but as I can't easily get the cab apart now to apply light proof paint to the offending points, it'll have to do! I've made a lid for the marker light enclosure in the cab underside, with a small hole for the white LED to go through and fitted a masking plate over the rear of the headlight. All painted black in an attempt to prevent red rear light glow getting into the forward lights. Before the lids went on, I glued a pair of white plasticard 45 degree reflector plates inside to get a more even white light visible through the marker light lenses....... Yes! that's done the trick!  Now checked in darkness and I'm happy with the result. 

Had to paint the inside of the body shell below the cab assembly, matt black to stop light leaking out through the plastic.

But there has to be a better way to sort out these lights!




The second 47 update, 47832  "Solway Princess":

First impression is that this is a more appropriate locomotive for the front of the train. There are a few subtle additional details to the livery compared to Galloway Princess! So, I'll configure 47832 for front operation and fit the detonator LED by the right hand front wheel.  I may have to re-jig the first loco to run normally in the reverse direction as it would be logical to have the driver of the rear loco at the rear of the train to facilitate reverse direction movements without the need for the locos to run round the train. (swop motor connections and re-assign the lights FOs).



Revised Approach to lighting mods for the second 47 update:

As a result of the first update, it is clear that to avoid cross coupling of light between the rear lights and the forward lights, a more radical lighting update is more appropriate. (The omission of the marker lightpipes by Vitrains may well have made this issue somewhat more of a problem, by making it easier for red light to show through the new lenses.)

In the second unit, the original LEDs will be removed and replaced by twin red rear light LEDs, twin white marker LEDs and a dedicated headlight white LED.... fitted within the lighting cavities below the cab, at each end of the loco. Once the system is operational, thorough shielding of both rear and forward light zones will then be possible.

The revised circuit implementation enables the lighting FO wires to be removed from the 8 way connector and routed directly to the new LEDs and their series resistors in the upper body assembly. It should look something like this:


The new marker light LEDs and rear light LEDs are mounted on plasticard carriers


Showing the marker light LEDs assembly glued in place

Showing the marker light diffuser and the rear light LEDs assembly glued in place

With all the light sources fitted to the cab assembly, there is no need to carve holes for the original chassis mounted LEDs, in the light shields.... so they can be made much more effective and easier to fabricate.

I'm also hoping that the new LEDs can be set at lower light levels than the originals due to their close proximity to the points of illumination....... which should further reduce light polution.


Opaque black paint applied to the roof underside before the final white coat

(To stop light from the cab light LED leaking through the roof.)


That's better, I'll be back when its dry!

Next the detonator flash LED:

Showing the location of the LED, adjacent to the front right hand wheel


LED active (using one of the now redundant 1k chip resistors on the main PCB as the series R)


Establishing the LED series resistor values:

With the cab re-assembled and the headlight fitted, the lights were powered up via estimated values of series resistors, using a bench power supply set to 13.8Volts. The resistor values were then adjusted to achieve what seemed an appropriate light intensity. The values chosen are as follows: New marker lights 4k7, new rear lights 6k8, the headlight remains at 6k8 and the cab light remains at 4k7. These values have been edited on to the circuit diagram for the second locomotive. (The values err on the bright side, so I may need to further adjust them if I'm not happy with the final appearance.)

Screening White from Red:

With all the running light LEDs now housed within the upper body shell, screening is a simple matter of fitting lids and screens to isolate the white lights and a partial screen to reduce overall red light leakage.

White zone screening before painting

After painting, also now including a partial screen over the red zone

That does the trick!  No obvious red light leakage into the forward lights when viewed in darkness.

In fact, the improved rear light works much better than my initial efforts on the first loco, so I'm going to retrofit 47790 with a similar approach. It may end up a bit on the bright side compared to the real 47s, but I really prefer it that way...... Job done and I managed to salvage and re-use all 4 red LEDs!



Driving Characteristics:     

Now the lighting is behaving (almost) as I want it, I'm starting to explore Paul's new Zimo driving system:

The latest Rail Exclusive Class 47 is the first release of Paul's new driving arrangements. It has some very useful new features!

The most obvious change is that key 2 now acts as a brake control. The momentum of a moving train is immediately apparent when you first shut the throttle down from anything above about 1/4 max. Instead of the normal slow down accompanied by automatic braking, that we have become used to, the train decelerates very slowly and the braking key is used to bring it to a stop (accompanied by the braking sounds). This enables a high CV4 setting of 75 to be used, which feels very believable.

Key 7 now provides a means to wind up the revs progressively to maximum regardless of locomotive speed. This can be used to simulate the start of a very heavy train, by using key 7 a little before the throttle is opened. When you get the timing right, the locomotive creeps away from a standing start, only after the diesel generator applies full power to the electric motors.

A light engine switch is included via key 5. When this is selected, the momentum parameters (set via CV3 and 4) are reduced to better reflect the behaviour of a moving loco, not coupled to a train. (The original setting of CV390 at 50, is fine for manual control, but resulted in a very lively light engine, when driven via coarser settings on the PC, which rightly or wrongly I calmed down with a temporary change to 128 for PC control.)

Key 6 provides the well proven Zimo reversion to idle.

Acceleration rates are now a function of the initial throttle setting. So if the throttle is eased open gently to a top speed of say 40/128, the loco will accelerate slowly up to speed step 40/128. However, if the throttle is flicked up to maximum speed and then immediately backed off to 40/128, the loco will accelerate at around 3 times this rate, again settling at a final speed step 40/128.

In addition, when controlling a moving train, the engine notching is sensitive to small throttle changes as in earlier Zimo projects by Paul. Plus now if the throttle setting is reduced in one hit by more than 10/128, the engine reverts to idle, but will then resume the speed step dependent notch level, as soon as the throttle is turned up again.


Now I've had a little more time to drive the locos, and I'm getting used to the control technique, I'm very impressed. I particularly like the combination of high CV4 to reflect the momentum of a 120ton locomotive and its train, combined with the new dedicated braking control on F2. It feels very convincing and the accompanying sounds work well.

The other big plus for me (which I'm hoping to apply to Class 66 and 60 freight locomotives when Paul fits his new driving system to those sound projects too.) is the use of the F7 key, independent of loco speed, so that the engine can be wound up to a believable level, before the loco gradually eases away with a very heavy freight train on the hook.

I've also been driving the locos in consist via the PC (via a Traincontroller schedule). The software enables both locos to be combined into a "Train set" where I can specify within a schedule, if function operations are applicable to both locos (e.g. all the driving controls) or just to the front loco (e.g. horn, cab light and detonator flash etc). This is a little more convenient than manual consisting via the creation of a consist address using the appropriate CVs, as using this route, the locos need to be placed on the programming track, both to set up the consist and then to revert to independent loco operation.

Using manual or PC driving, the engine revs track sensibly with the loco movements almost all of the time. I have occasionally caught the system out when faced with the need for an emergency stop, but its a rare occurrence!

Looking forward to getting equivalent reblows of my other Zimo decoders as Paul makes the new drive system available in sound projects for other locomotive classes beyond the Northern Belle 47s! (....and hopefully a few new ones along the way!)



Changing the direction of the first loco:     

I want to operate the rear loco with the number 1 end (which includes the driver) facing the rear. This means it will be running in the opposite direction to the lead loco. To reduce the complexity of consist operation, I want to eliminate this directional difference, so I'm going to turn the first loco through 180 degrees by reversing the motor contacts and swopping the lighting CVs

End 1 is still the fan end, so.......

The lighting CV changes are as follows:

CV Old Value New Value
33 5 10
34 10 5
432 1 2
434 2 1
438 14 15
440 15 14

 Address (CV1 also changes to 6)


OK, that works fine.......



Running the two Northern Belle 47s in consist:     

At slow speeds, the first loco is moving noticeably faster that the second, when set to the same speed step..... doesn't bode well for operating the two locos in consist?

Actually, using my Lenz controller in dual loco consist mode with the locos, but with a 20cm gap between them, they maintain that gap almost exactly as they manoeuvre, so DCC consisting successfully takes care of the speed difference problem! However, the function keys are all loco specific on the Lenz controller, so I can't apply simultaneous braking or any other function keys implementing drive commands simultaneously using the Lenz consisting arrangement.......

Trying Zimo "Advanced Consisting" Set CV19 to 20 (=consist address)   Set CV21 to 114 (makes keys 2,5,6 & 7 respond to consist control.) Set CV22 to zero (keeps other keys independent). Initially this worked fine, using address 20 on the Lenz controller. The drive keys could indeed be operated simultaneously for both locos. Then I had to shut down the controller, returning later to restart. After the restart, the locos movements were no longer properly synchronised. Not sure what had gone wrong, but the experience doesn't fill me full of confidence in this, as a way forward. However, if I cannot find a better solution, I'll come back to it and work out what went wrong, and how to keep it working correctly.

My Traincontroller PC control software has a consist arrangement.....reminding myself of its capabilities, I'm relieved to see that I can use "function forwarding" to simultaneously activate a function or functions in both locos, although I can only control loco specific functions during a schedule run, in the lead loco. (Specific functions e.g. lights, can be manually set-up in the rear loco before the schedule is started though). When I've finally finished optimising the locos, I'll get this up and running.........   A few hiccups, but I now have a shuttle run with both locos working successfully on the test track....... not enough room for the whole train, so, I'll run a sequence of demos to show the lights and sound system in action plus a simulated station scene with the entire train.

Sequence 1) locos start, radio check, run light engine to couple up in consist, then switch inappropriate running lights off.

Sequence 2) Consist up the test track braking after detonators and returning with flange squeal.

Sequence 3) Static sequence with station sounds including the entire train.


Adding the remaining Vitrains detail parts:

There are quite few detailed parts that can be added to the locomotives from the large collection of additional mouldings, provided with the locos. When I've done a bit more work on the PC demonstration schedules, I'll sort out the appropriate enhancements and glue them in place, before producing a video. I'll start with 47832 as this will normally lead the Northern Belle train, so will not use a tension lock coupler on the front......

Hmm! Lots of bits, but only a few applicable to 47832! and the orange boxes beneath the buffer beam are not provided for either loco.

First stab at 47832.... just the front end so far!

47832 has a conspicuous step fitted to each end of its buffer beam. Vitrains provide parts, but they are designed to fit within the front skirts of the upper body, while being glued to the chassis. The bogies inevitably hit these step mouldings, when turned through a tiny angle. So, instead, I've trimmed the parts to just the visible parts below the buffer beam, and glued these to the underside of the buffer beam in such a way, that the upper body can still be separated from the chassis. The central lamp bracket has been trimmed back & painted white, but still looks over-scale. I only had original super glue in the tool cupboard and I dare not use this anywhere near polystyrene transparencies due to the hazing effect of the fumes. So I had to be patient and use Glue 'n Glaze to stick the parts in place. I'll get some gel fumeless superglue tomorrow before fitting parts to the rear of 47832 and 47790 in its entirety. (Although I'll stay with Glu 'n Glaze for anything close to the windows e.g. those flimsy windscreen wiper parts.)






That largely completes the locomotive upgrades .............. But before a video:


Painting a pair of Hornby Mk3 sleeper coaches to add to the Northern Belle consist

MK3 Northern Belle Sleeper:     

Hornby once produced the "Crewe" Mk3 Sleeper in NB colours...... but these are now rare beasts and fetch a good price on ebay..... so looking for alternatives, I found that Hornby are producing a pair of First Great Western sleepers, with an expected release date of 6 March 2015. I've pre-ordered two, but their boat hasn't come in on time...yet!

After the difficulties I had masking windows on the NMT project, I'm going to brush paint these units, using Humbrol enamel paints.

Searching for suitable transfers, I discovered instead, self adhesive plastic sheets from Precision Labels and Decals, which include the Crewe and Balmoral NB sleepers. However, these need the bodies to be prepainted with the cream window band and NB "Crimson Lake" around the doors and coach ends (and of course weathered white roofs). So the first challenge is to find matching enamel paint colours. I'm not convinced that the Hornby Mk2 coaches and Rail Exclusive locos use quite the same shades as the real train, so decided to try and copy the shades on the 1/76 size rolling stock. So far Humbrol 73 "wine" plus a little black is the best I've achieved on the darker colour. 41 Ivory looks close to the window band on the photos I've found of the original train, but it needs more yellow to match the Hornby/Rail Exclusive cream.  103 cream matt is too muddy and 148 radome Tan matt is too pink, so I'm going to have to try adding a little yellow (24 trainer yellow) to matt white in an attempt to get a better match. (The matt colours may also need some light polishing or satin varnish to get the texture a little less extreme.)

Late March 2015 and the coaches have now arrived:

The raised FGW "waves" markings along the coach sides will show if over-painted.


The raised markings were therefore removed with wet & dry sanding.


The roof masked at cant rail height.

First coat of custom very pale matt grey applied to the roof.


Second coat of pale roof grey....maybe a bit on the pale side?


Cream Looking less than smooth after first brush coat


Corridor side after 4 brush coats


Compartment side after 4 brush coats


Main self-adhesive sheets applied



Main self-adhesive sheets applied




Ends painted to (nearly) match the panels and smaller self-adhesive sections fitted at the cream zone ends and above the doors.


Managed to paint around the FGW end labels.

Next....Balmoral !


"Crewe" and "Balmoral", now ready to add to the front of the Northern Belle Train.



Next, the video.......first, need to get some track ready in the loft as the test track is now too short!


Problems with one of the Northern Belle Zimo decoders!

Having finally completed track phase 1 of the loft layout, I thought it was about time I did a brief video of the train in action...... until the lead unit developed a split personality. When in consist with the second machine, it would periodically revert to a mode in which an abrupt start was followed by very sluggish ongoing movement resulting in the rear loco crunching the train together. Eventually, this effect became the predominant mode of operation.

In an attempt to resolve the problem, I subjected the lead loco decoder to a reset (setting CV8 to 8). The good news is that this seems (so far) to have cleared up the problem, with movement now returned to normal..... but of course I had to revisit the programming of the CVs that I had originally changed, in order to accommodate the lighting control.

I could immediately see a better way to deal with the Swiss mapping, which meant that the only original functions I elected to loose (to make way for the lighting controls) were the overall volume fader/mute on F19 and the zero momentum shunting mode key on F20.

This simplified the additional programming required and kept all the sound clips active..... so I decided to proceed with this approach first with the problem lead loco and then again, with the rear loco, to maintain identical behaviour. 

Function operation after the reset:

The Zimo MX645 function mapping list that arrived with the locos
F0 Master lights switch F15 Scavenger Fans (also a random sound)
F1 Sound on/off Engine start / shut-down F16 Platform Announcement
F2 Brake application F17 Despatch Whistle
F3 Playable Low Horn F18 Spirax Valves
F4 Playable High Horn F19 Fade-Out of sounds (3 sec)
F5 Light Engine mode (and "cold start" trigger) F20 Shunting Mode (Half Speed, Zero Inertia)
F6 Coast/Idle button F21 Lighting adjust
F7 Full Power button F22 Cab Sound: DSD vigilance warble
F8 On/Off Buffering-up/Coupling thrown over hook F23 Cab Sound: AWS Warning
F9 Flange Squeal (variable length) F24 Detonators exploding (decelerating)
F10 Brake (Air) Release F25 General Station Ambience
F11 Two tone horn F26 Platform Announcement (some versions only)
F12 Driver's door open (on) / close (off) F27 Live Volume control Down
F13 Driver's Pre-start checks (on) / Post start checks (off) F28 Live Volume control Up
F14 Triple Pump Starts & Runs (on) / Stops (off)    

For my lighting control:

..... I need four button assignments:  So, I'm going to have to remove some original functions to make room for the lights switching:

                                          I'm going to remove: Shunting Mode (F20) & Fade out of sounds (F19)

The lighting will then use Swiss mapping:

Function Button Forward FOs Reverse FOs Swiss mapping Group
0 FO6 FO6 1
19 FO4 - 2
20 FO1 FO2 3
21 FO(H/L) FO(R/L) 4


Delete Shunting Mode from F20)......  Disable shunting mode/zero momentum via CVs 155 & 156 which define F keys.

Set CV313 to zero to remove mute, 

Set CV33 & 34 to zero to remove conventional mapping on button F0.                   

Set CV127 to zero and set CV132 to 60. To make the cab light only enabled when the loco is stationary.

Swiss mapping for the running lights:

Description CV Value
Group 1      F-Key 430 29
M-Key 431 0
1st fwd FO 432 6
2nd fwd FO 433 0
1st Rev FO 434 6
2nd Rev FO 435 0
Group 2     F-Key 436 19
M-Key 437 0
1st fwd FO 438 4
2nd fwd FO 439 0
1st Rev FO 440 0
2nd Rev FO 441 0
Group 3      F-Key 442 20
M-Key 443 0
1st fwd FO 444 1
2nd fwd FO 445 0
1st Rev FO 446 2
2nd Rev FO 447 0
Group 4      F-Key 448 21
M-Key 449 0
1st fwd FO 450 14
2nd fwd FO 451 0
1st Rev FO 452 15
2nd Rev FO 453 0



Resulting Function Mapping Chart

The Final Zimo MX645 function mapping list
F0 Cab light (driver end only)
F1 Sound on/off Engine start / shut-down
F2 Brake application
F3 Playable Low Horn
F4 Playable High Horn
F5 Light Engine mode (and "cold start" trigger)
F6 Coast/Idle button
F7 Full Power button
F8 On/Off Buffering-up/Coupling thrown over hook
F9 Flange Squeal (variable length)
F10 Brake Air Release
F11 Two tone horn
F12 Driver's door open (on) / close (off)
F13 Driver's Pre-start checks (on) / Post start checks (off)
F14 Triple Pump Starts & Runs (on) / Stops (off)
F15 Scavenger Fans (also a random sound)
F16 Platform Announcement
F17 Despatch Whistle
F18 Spirax Valves
F19 Detonator flash LED (47832 only)
F20 Driver's end (fan end) directional lights
F21 Non-Driver's end directional lights
F22 Cab Sound: DSD vigilance warble
F23 Cab Sound: AWS Warning
F24 Detonators exploding (decelerating)
F25 General Station Ambience
F26 Platform Announcement (some versions only)
F27 Live Volume control Down
F28 Live Volume control Up


Testing The Lead Unit:

For once, all worked OK. So I took the opportunity to increase the volume of the horn, the station announcements and the pre/post start checks and increased CV 3 to extend the acceleration delay a little. One intriguing change was the platform announcement on F16: I'm sure the original voice was female...but since the reset, its male!

Updating the second unit (without applying a preliminary reset.)

This went reasonably well until I tried to use sound slot data from the lead loco, to re-establish some of the sounds now restored to the lead loco, in an equivalent manner to the rear loco. The two tone horn and scavenger fans turned out to have different sound slot assignments in the rear loco compared to those in the reset lead loco. Took me a while to find them, but I eventually sorted it all out...... and sure enough, the platform announcement in the rear loco is indeed a female voice rather that the corresponding male voice in the lead loco.  No problem, but I'm still puzzled about the differences between the two decoder's behaviour!

However, as I had previously wired the motor on this unit to drive with the manned cab facing the rear (to facilitate simple reverse workings) the F20 & F21 Swiss mapping entries (Groups 3 & 4) also needed to be reversed, resulting in the following CV settings for the running lights:


Description CV Value
Group 3      F-Key 442 20
M-Key 443 0
1st fwd FO 444 2
2nd fwd FO 445 0
1st Rev FO 446 1
2nd Rev FO 447 0
Group 4      F-Key 448 21
M-Key 449 0
1st fwd FO 450 15
2nd fwd FO 451 0
1st Rev FO 452 14
2nd Rev FO 453 0

The motor control parameters were also updated to be identical with those of the lead loco, to facilitate operation in consist.

We are up and running again and so far both locos are behaving normally, with good speed tracking over the range of speeds to be used.

Time for some video work!...................

A brief video can be found on You Tube by clicking here


Appendix:   Some useful Info:


1. A CV List Supplement to the Zimo 2014 small decoder manual aimed at sound decoders only:

The manual provides a list of individual sound volume adjustment CVs for each controller key. It also mentions that associated with these CVs are sound slot numbers and looping data, but doesn't explicitly advise on the CV numbers concerned. Adjusting these CVs is the quickest way to remap sounds between control keys, by reading the three source key CVs and transferring this data to the three corresponding destination control key CVs. A bit of experimenting with a Zimo equipped Class 66 enabled the following table to be generated. So it definitely works with software version 33 and higher on an MX644D.





2.  March 2014 Northern Belle Consist Borrowed From Rail Magazine's May 2014 Centre Spread:

The complete 2014 consist has 11 cars, I have layout room for only a subset of 6, which conveniently are now available from Hornby and are ready for the 47s. However,

I might be tempted to customise at least one or two of the remaining coaches if I run out of project work!



Supplier website links:


Rail Exclusive The source of the Northern Belle 47s and their Zimo Sound Kits
Zimo The Zimo decoders website, the MX645 manual can be downloaded from here, its "Small" decoders - for N, H0e. H0, 00, 0  English edition 2014-04-20 (right hand side)
Digitrains Probable source for white and red nanolight LEDs
Hattons The source for my 6 Hornby Northern Belle Mk2 Pullman cars




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