Hornby Terrier - Couple of options,

[gz3xzf]

Sorry if this has already been covered, I did do a search and couldn't find a topic covering the Hornby Terrier.

 

I have fitted decoders to a couple of Hornby Terriers, the first was one for my sons layout, which was No55 Stepney, for this one a used an idea from the Bromsgrove web site where a small decoder (a Digitrax DZ125) is fitted in the bunker.

First I removed the body from the chassis and the cab from the rest of the body, you'll find that without to much force the cab back can be removed and the bunker extension: -

Indicated by the arrow is a strengthener that is molded into the bunker back, I removed this carefully with a sharpe craft knife or a scalpel.

I then drilled a hole through the weight and the footplate: -

I then cut strips of insulation tape and insulated the metal weight, the strips were passed through the hole and stuck down top and bottom; the remainder of the top of the weight was covered in tape: -

You can then reassemble the cab and place on the footplate, the decoder sits on top of the weight and sticks up into the bunker extension. I trimmed off the unwanted wires, leaving only the red, black, orange and grey wires: -

The wires are then passed under the footplate into the space where the motor is (in the tanks and boiler), the Terriers wiring allows a very simple connection of the decoder, the black wire of the decoder is attached to the left hand pickup, the red to the right hand pickup, the orange and grey wires to the motor.

[gz3xzf]

The second method I have used a couple of times now, one using a TCS M1 & the other using a Gaugemaster DCC22 Very Small Loco Decoder;

this method uses the air gap that exists above the motor to the boiler/tank top.

I got an idea of the space available by using a piece of plasticine or Bluetack, make sure it is very soft (by kneading it for some 2 or 3 minutes before hand), place it on top of the motor and refit the body (carefully pushing down on the dome) until it has reached home. Take the body off again and the piece of plasticine has the height of the space available.

OK, these are the steps, first with the body removed, take note of where the wires are located: -

Unsolder the supression capacitor from the motor and the pickup connections. Cut the 8-pin plug off the decoder (leaving at least 2.5cm of wire, trim the unwanted wires from the decoder (these can always soldered back on if later required) and strip the ends of the remaining wires: -

Now solder the red & black wires to the pickup leads and the orange & grey wires to the motor (I connected the grey wire to the left and the orange to the right): -

Add some heat shrink tubing to the wire soldered connections.

Now cut a piece 20thou plastikard to cover the top of the motor (18mm x 20mm) and use a small amount of glue (I used UHU), make sure the wire connections are towards the sides and the chip is over the top of the plastikard: -

 

[tersono]

With a little care and some careful relocation of the pickup wires, a slim decoder can be affixed to the side of the motor with a sticky fixer (some have used bath sealant). There's not a lot of space, but with care you can get the decoder to fit between motor and the inside of the tank side.

 

Sorry, no pics, but of the three Terriers I've chipped so far, this was by far the easiest, requiring no modification of the body at all.