DCC conversion and Lighting update of the Hornby Class 60 freight Diesel Locomotive.

  

 

Introduction:

This webpage provides a summary of the process adopted to incorporate a DCC decoder and correctly operating LED lighting in a DB Schenker respray of the Hornby Class 60 OO gauge diesel locomotive.

Note that the smaller pictures can be enlarged by clicking on the image.

 

EWS liveried Class 60 shunting at Ely Station in 2009

(Number 2 end, with the exhaust, is at the front. Number 1 end, with the main fans, is at the back)

DCC Conversion Approach:

The plan is to use an ESU 6 function and back emf motor controller LokPilot V4 decoder in an arrangement that allows DCC control of day or night lighting, enabling or disabling of the rear lights and also includes a facility to add strobe shunting warning lights to the brackets at either end of the locomotive.

External Lighting:

The original lighting fit in the Hornby model is quite representative of the real locomotives. However, some adjustment of brightness levels and colour are required. Convenience also dictates that in place of the manual day / night operation switch on the underside of the model, the DCC controller will be able to select the required combination of lights. Also the rear lights need to be capable of disabling.

It is planned to use button 0 for day running lights or button 1 for night running lights. Button 9 will also be used, to enable the rear lights. Provision for add-on orange strobe lights will also be made, controlled by button 6.

 

Day running Lights as the loco approaches the camera

(right headlight and left marker light).

At night, left headlight and right marker light are used instead

Rear Lights as loco moves away from the camera

(curiously the right marker light is also on, but this is a fault)

 

 

Rear Lights operation:

The rear lights are only used when the locomotive runs "light engine", without a train of wagons. When the locomotive tows a train, the locomotive rear lights are switched off and a dedicated strobing rear light is fixed on the rear bracket of the final wagon in the train.

The strobing rear light is about to be taken to the far end of the train and mounted on the rear of the final wagon.

 

The locomotive rear lights are switched off as the train pulls away.

 

 

The locomotive arrives:

The loco arrived from Olivia's Trains of Sheffield with some minor transit damage, which I was able to fix. The finish looks pretty good, certainly a lot better than I could have managed, but with the odd imperfection that illustrates just how good the latest factory finished locomotives have become. Making it tough to achieve an equal standard.

As received above..... and after a couple of repairs below:

The light lens fronts look a bit rough.... almost as if they have been scraped?  I'll try a bit of gloss varnish when the functionality is sorted out. One annoying feature that I can't easily sort is the small DB label on the front , which is not quite level!  The shroud around the horns also looks a bit strange (Hornby design issue).......but that I can fix!

Postscript: A few days later, one of the doors fell off due to a broken hinge mechanism..... another repair job dealt with!

Perhaps the Christmas rush is the reason I haven't yet received a response from my email to Olivia's sent 21st December 2011, advising Olivias Trains on their quality problems and requesting they provide the missing accessory parts (as only a single tension lock coupler was provided in the accessory pack)  ????   Not the end of the world, but it is unusual these days to find a company where after sales customer service does not appear to be thought necessary!

 

Achieving Access to the locomotive:

First the upper body shell must be separated from the wheeled chassis unit by carefully pulling apart the body shell sides until the clips release.  I found it helped to slip thin pieces of cardboard between the body shell and the internal metal casting at each clip position, one at a time...... then pull them apart when all clips are bypassed.

Upper and lower body separated

 

 

The Lighting  System:

It is not really a surprise to find the usual complex Hornby lighting solution, using a negative common supply to each of the lighting PCBs. (Why Hornby use a Pic micro, a couple of opto isolators and several transistors, to perform the same tasks that Bachmann achieve with a much simpler circuit is a bit of a mystery!)

The connections at each end of the chassis are 4 way tabs that make contact with corresponding tabs on the lighting PCBs, fitted to the cab assemblies at each end of the upper body assembly.

 

Cab underside

 

Front view of cab

Underside of cab

 

Circuit of the lighting PCB fitted to each cab

 

The LEDs beam light into discrete lenses, mounted in the front face of the body shell.

Coupling the lighting LEDs to the new decoder circuit can be done in a variety of ways:

1. The LEDs could be removed from the lighting PCBs and then re-fitted with the polarity reversed......  Not an easy job, with a high chance of LED damage!..... but the simplest circuit solution!

2. The LEDs can be controlled in a positive ground decoder environment, using PNP switching transistors. Low risk of damage, but increased circuit complexity.

3. To allow for dimmer marker lights in 1. or 2. above, the appropriate 33R resistors can be removed from the lighting PCBs and separate wired connections taken to the main circuit board.

4. To avoid the need for 3. It may be possible to simply add yellow water colour paint filters to the front of the marker light LEDs and/or to the rear of the marker light lenses. If successful, the headlight/marker light pairs can then simply be driven in parallel.

 

So the first experiment will be to apply yellow water colour paint to the marker lights:

Applying a coat of yellow water colour paint to the front face of the marker lights works pretty well! The light level drops and the colour looks quite similar to the real marker lights, which use old bulb technology. So I'll proceed on that basis. (Corresponding to 2. and 4. above.)

 

Cosmetics:

I've been trying to improve the appearance of the badly scratched light lens fronts by applying "Glue 'n Glaze" with some success. It will take at least one more coat and a bit of careful painting around the lens rims, but its getting there!

The shroud around the horns at the number two end looks much larger than than the real thing, as shown in the EWS 60 photos at the start of the page. So I've dismantled it, removed a couple of mm from the base of the shroud side plates and re-assembled horns and shroud using super glue. Still a shade bigger than the real thing, but much closer! 

 

Circuit solutions:

To control the common negative lighting circuit boards from a common positive decoder, a circuit along these lines is required.....

 

May have to order up some more PNP transistors!       (If only Hornby used circuit solutions with a common positive supply instead of negative!!!!!  .......   )

Can't think of a simpler solution unless I dismantle the lighting boards, remove all 12 LEDs, then replace them with their pads reversed. Not a fun job!!!

 

 

Adding the cab light:

Having located a suitable driver figure from the spares box, I'll also add low level cab lighting. All 6 function outputs are already assigned, so the cab light will be connected in parallel with the night forward lighting. I don't want to add wired connections between the upper body shell and chassis mounted main PCB for this purpose, so I'll tap the appropriate points on the lighting PCBs. (Upper front track for common negative and top end of R6 for the 220R current balancing resistor in series with the cab LED.) 

Cab light circuit diagram

 

Night running LEDs with parallel cab light

(14V via 2k7 overall series resistor to the lighting PCB and yellow painted white cab light LED connected via 220R resistor across contact tabs)

 

Common negative connection

Night+ connection on R6

 

 

 

 

Orange strobe lights:

These are modelled on the standard UK Dorman rear lights, but use amber LEDs. The idea is that they are clipped on to the lamp brackets at each end of the locomotive, to provide extra optical warning of locomotive movements during yard operations. Using a double strobe emission, they look very effective despite being more a product of imagination than actual fact..... unless of course you know differently!

Amber pre-wired 0603 LEDs are installed into lamp mouldings, provided as spare rear lights from Bachmann Nuclear flask wagons. The lamps are glued to the loco lamp brackets and the thin enamelled wire leads are passed through tiny holes drilled behind the lamp brackets, into the loco interior. The lamps are wired in series, and use a common 820R series resistor, mounted in the upper body. Two wires connect the installation to the chassis mounted main PCB.

External strobe light glued to lamp bracket

Wiring arrangement

 

 

New circuit to allow the use of a positive ground decoder with Hornby's negative ground LED circuits:

The first task is to remove the Hornby SMD components from the main PCB. I find the use of two miniature soldering irons works well:

PCB stripped

The next job is to isolate the connection tabs for the LED wiring, so that these can be reused as anchor points with the new circuit. This requires a few strategic cuts with the Stanley knife.

The new circuit is built using leaded parts soldered together, to fit on to the PCB area. A PNP transistor is required for each function wire, to switch the positive feed to the relevant LEDs.

 

New circuit in place

 

Double sided, self-adhesive foam tape is cut to fit the top of the PCB, and then fixed in place. The new circuit is soldered together away from the tape, but when complete is carefully located on to the exposed adhesive, which both holds it in place and insulates the new parts from the original tinned copper track pads below.

 

Fitting the decoder:

In order to access the Aux3 and Aux4 function outputs, an ESU accessory PCB is required. This incorporates amplifiers for the low level Aux3 and Aux4 signals available from the 21 pin decoder, converting the microamps available from the decoder to milliamps. Double sided adhesive foam tape is used to mount the decoder adapter PCB on top of the grey machinery simulation near the number 1 end of the locomotive. The adapter PCB wires are connected to the new circuitry on the main PCB, as indicated in the circuit diagram.

Decoder wired in

 

Upper body shell & Bottom chassis ready for re-assembly

 

Programming the CVs:

Using the DCC controller (mine is a Bachmann Dynamis) the decoder CV values are programmed. (The details can be found in the ESU LokPilot V4 English Manual available from the ESU website.)

CV Description CV 31 CV32 CV Value

Set Speed control to 28/128 steps

- - 29 2
Button 0, Forwards only: forward (day) Fwd light function (white) end 2  (default) 16 2 330 1
Button 0, Backwards only: forward (day) Rev light function (yellow) end 1  (default) 16 2 346 2
Button 1, Forwards only: forward (night) Aux1 function (green) end 2  (default) 16 2 362 4
Button 1, Backwards only: forward (night) Aux2 function (purple) end 1  16 2 378 8
Reset Button 2 Fwd from default value to zero 16 2 394 0
Reset Button 2 Bwd from default value to zero 16 2 410 0
Button 6 Forwards only: Strobe Aux4 function on 16 3 266 32
Button 6 Backwards only: Strobe Aux4 function on 16 3 282 32
Button 9 Forwards only: Rear light enable Aux3 on 16 3 362 16
Button 9 Backwards only: Rear light enable Aux3 on 16 3 378 16
Set Aux4 double strobe function 16 0 299 6
Set Aux4 to LED mode 16 0 303 128
Set strobe cycle time to circa 1 second - - 112 15

 

 

Testing the Lights:

Button 0 activates the day running lights

Button 1 activates the night running lights & forward cab light

Button 9 enables the appropriate rear lights

Button 6 activates the shunting strobe lights (double strobe flashing action)

 

Day running front lights end 2 (button 0)

 

Night running front lights & cab light end 2 (button 1)

 

Rear lights end 2 (button 9 and [0 or 1])

 

Day running front lights end 1 (button 0)

Night running front lights & cab light end 1 (button 1)

Rear lights end 1 (button 9 and [0 or 1])

Double Strobe lights (look more impressive if you see them flashing)

(button 6)

 

Debugging:

After initial programming, all lights and motor functioned as planned, with the following exceptions:

1) The cab light did not operate.  Investigation revealed that a thin enamel coated wire on the rear of the cab back wall had been broken. The wire was repaired and an overall coat of glue was added to strengthen the wiring at this point.   (The break can just be seen on the re-assembly photo above, to the left of the resistor on the back of the left hand cab wall..... although I didn't notice it at the time.) Now working fine!

2) The double strobe effect applied to the add-on lamps had a rather slow switching rate. This can be adjusted via CV112. The default of 30 gives a cycle time of just under 2 seconds according to the manual, so a new value of 15 will be tried....... much better!  (Change now added to CV table above.)

 

Remaining issues:

Remove dog hairs from tension lock coupler and dust from cab windows!

 

The completed Locomotive

Supplier website links:

 

Olivias Trains    The resprayed DB Schenker Class 60 unit above was purchased from Olivia's. Broken front parts & missing accessories on arrival and no response to my email!     Be aware!
Digitrains    A good source of all things DCC including pre-wired chip LEDs from DCCC.
Bromsgrove Models    Excellent source of specialist LED devices for this type of project
South West Digital    Primary ESU decoder dealer in UK
Rapid Electronics    A good low cost, high speed supplier of electronics components etc
Maplin    A convenient local source for electronic components such as resistors and transistors

 

The photos of the real class 60 were taken at Ely station in 2009.    The photos of the model were taken hand held on the kitchen worktop using a Canon IXUS 220HS.    

 

Click to move to Model Rail Index Page