Tinkering with the Dapol Class 73

April 5, 2018

My enthusiasm for my Folkestone East layout has not been at a low ebb, but work being done to the layout is routine – little worthy of reporting. Refinement in some of the wiring together with a look at block occupancy detection for the main ‘Ashford’ staging yard has been the main activity together with working through piles of new equipment accumulated over the last few years.

One of those pieces of equipment is the Dapol Class 73 of which I finally bought in five to replace five old Lima models and a couple of Hornby ones. As soon as you buy new locos, there’s new projects to start and in this case, some reliability upgrades and repainting too. I must confess to not liking the Dapol model on sight – it was its poor livery colours, particularly the yeellow that did it for me initially. The roof colour on the model of No. 73138 is sort of okay when you see how Executive Dark grey faded over time, but not as uniformly as  applied to the model.

However, underneath the otherwise very neatly applied but less than accurate paint colours is a pretty nice model with oodles of detail. I have bitten the bullet and started some repaints of the model as well as upgrading the not so reliable current collection system. When a painting ‘mojo’ strikes, and they rarely do, masking tape and painting supplies takes quite a hammering! Thankfully, the Dapol Class 73 is reasonably easy to dismantle and work on.


First up is discovering how the bogies and electrical pick-up are arranged – parts may fall off the cosmetic bogie frame when being removed – note the middle retaining clip! As you will see, it is possible to add simple wiper pick-ups with either nickel-silver wire or its phosphor-bronze equivalent.

Pick up arrange on the Dapol Class 73 after the bogie frame has been unclipped.

Drill two holes clear of the bogie frame clip and on both sides of the frame to accept 0.4 to 0.45mm diameter pick-up wire.

Cutting a length of pick-up wire to the length of the bogie which after bending to shape, will be the ideal length.

The wire is bent like this and fed through the holes drilled through the inner bogie frame. Repeat for the opposite side and the second bogie.

Bend the wires so they will act on the back of the wheels as pick-ups.

Solder (very carefully) the wires to the existing connecting strips to complete the circuit. Adjust the pick-ups once the wheels have been refitted.

Painting of two of the models in Intercity Executive livery is underway and has reached the touching in stage to tidy up lining and prepare for transfers. Whilst doing this, my trust old Bob Moore lining pen finally packed in after 30 years of reliable service, so I resorted to a bow pen for the thin orange lining – less than successful. A new lining pen is on its way which will see the lining tidied up a little.


Other reliability work on the Dapol model included going over the finely assembled bogies and under frame detail with Plastic Weld to secure the individually moulded detail parts before the fell off and became lost. Thankfully, they seem to be moulded from a plastic which can be glued together with sparing amounts of a powerful solvent adhesive!

A decoder with ‘Keep Alive’ circuits is also being installed in each model and indeed, to as much of my collection as possible. I value reliable running and flicker-free lighting more than digital sound. The space left for a speaker in this model will accommodate a pretty big Keep Alive unit!


One of the really great things about the Dapol Class 73 as far as EM gauge modellers are concerned is the wheels. They are fitted to split axles inserted in insulating drive gears with large bosses on either side. With the current collection via axle bush rings, the wheels can be easily regauged for EM track. Fortunately, the wheel profile runs through my track work allowing me to place out the box models into traffic as soon as there is a decoder fitted to the model.
Also worthy of note is the nicely arranged interior and simple electronics which allows for the hard wiring of decoders for simplicity together with space for Keep Alive units. I remove the circuit boars and hard wire decoders allowing me to arrange lighting to suit my needs – the cab light is isolated as a result. Access to the interior of the body for this work is also very simple – undo four screws and the body slides straight off – no clips or anything like that to catch you out. So there it is – the Dapol 73 is being introduced to my Folkestone East layout at last.

 

 

 

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Dapol Class 73s…into traffic!

March 28, 2017

No. 73 108 in late condition, photographed at Eastleigh in 2002.
Faded, dirty but still doing its stuff on the SE TPO.

No. 73 108 is one of the locomotives I have chosen to model using one of the two new Dapol models to recently arrive on Folkestone East. Conversion to EM turned out to be the simple, involving the regauging of the split axle wheel sets which have a good profile on them – good enough to run smoothly through my hand built track.

There are many well-thought out technical features of this model. The body lifts straight off after releasing the retaining screws – no pesky clips to fight. Don’t loose the screws though or you will be scr*wed when it comes to putting the body back. There is a good space for both decoder (nearest) and a sound speaker. A 21-pin socket ensures all lighting features have power.

The circuit board makes contact with circuits in the body by means of a row of sprung contact pins which eliminates linking wires and plug and sockets. However, I did not want the cab lights illuminated and was looking to fit a decoder with ‘stay-alive’ (‘keep-alive’) . The only one I had to hand was a wired LaisDCC one which works well with this mechanism. 21-pin versions with stay-alive are also available. I also wished to work the head code lights independently using red LEDs, so decided to remove the circuit board and hard wire a LaisDCC decoder in place with its stay-alive capacitor. The lighting connections to the circuit board are easy to locate and desolder, so this hard wire DCC conversion is easily reversed – the circuit board being stored away safely.

The image above shows the hard wire installation, with the head light LEDs wired with 5k Ohm resistors to reduce the fierce light to something a little more realistic. Connections will be made with the head code box LEDs too.

A stay-alive unit is seen in this image. It was not quite powerful enough to power the Dapol Class 73 when it lost contact through those pick-up bearing rings. In the end, I built a new stay-alive unit with some higher Farad rated capacitors with great success. The higher rated unit was still connected to the same LaisDCC decoder. It is worth mentioning that even the smallest capacity stay alive unit will prevent light flicker in the most reliable models even if there’s not enough juice to deal with a serious stall. In many instances, the flywheels fitted to modern mechanisms will carry a loco over a minute dirty spot without interruption,. The only hint of a problem will be a flickering of LED head and tail lights. Stay alive units also smooth the operation of locomotives that otherwise seem to run well.

A final look at the DCC installation. It may seem strange to remove the convenient 21-pin DCC interface. However, wired decoders offer so much more flexibility in terms of organising lighting effects and this installation turned out to be quick and effective. The model is numbered 73 108 with an address of 3108 and is now hauling trains on Folkestone East. It is at this point I must admit to keeping two Lima EDs, stripped of drives and in the process of being reworked with Dapol detailing parts. One is No. 73 129 ‘City of Winchester’ which is used as a trailing unit in the SE TPO so the train can be top and tailed. Two Dapol EDs on this train is overkill. The second loco was also a regular on the SE TPO: No. 73 131 which will eventually be refinished in EWS livery.