Starting to build "Carisbrooke"

This is to record my progress building a P4 version of the new EB Models etched brass kit for a Belgravia.

I am building No.206 Carisbrooke with the larger Craven tender. To meet my particular requirements I will be modifying the recommended construction method in a number of areas:

• Sprung axle boxes for all wheels.
• Split axle pickup from as many axles as possible.
• DCC decoder mounted in the tender.

Tender

The tender was part finished in time for the Brighton Circle AGM in October 2007 and had the following modifications:

1. Be sure to add the retaining nut inside the tender body before you enclose the space completely.
2. I have added a large cut-out in the base of the body and footplate to allow access & the fitting of the DCC decoder.


3. The upper handrail brackets need to be adjusted to fit to match photographs.
4. The chassis uses a piece of PCB as a spacer to isolate both sides electrically.
5. A guitar string was used in conjunction with a set of London Road Models axle boxes, horn guides and spring mounts to provide a continuous springy beam each side of the chassis.


6. Sharman 3'9" wheels were shorted between the Branchlines split 2mm axle and the rim to provide an electrical path.

General view of the tender body:

Loco Body

Work then started on the loco body which has given some challenges:

1. When trying to fit the cab-sides the outer chassis frame spacers got in the way. These were removed and the cab-sides (and spacers) fitted to the (carefully) formed footplate directly.
2. It's not clear when to add the half-etched outside chassis frames, I haven't yet added them. They will need to be added before the outside frame axle boxes.
3. The bottom of the cab-front needs to be narrowed to clear the driving wheels.
4. Make sure the cab front fits between the cab sides rather than in front. Otherwise this will cause the boiler to be pushed forward and it won't fit between the cab front and smokebox assembly.

General view of the loco body parts to see how they fit:

Loco Chassis

The instructions sensibly recommend building the chassis once the main part of the superstructure is complete. This allows inspection of clearances for the motor, wheels and chassis frames.

I wanted to fit sprung axle boxes to all axles, and this meant adding a strengthening plate to the chassis behind the rear axle and cutting out a horn block slot to match the other axles. For the loco I have used the High Level fold-up horn guides and axles boxes, together with the London Road Model spring mounts.

I found that a Comet GB4 38:1 gearbox and Mashima 1020 motor will fit at an angle in the firebox and drive the centre axle.

With the outside framing, I cannot see an easy way to provide split axle pickup without creating a 5-part extended driven axle!  So I will probably use CLAG style stylus pickups on the drivers. This together with the tender pickup and springing will mean that there should be five electrical points of contact each side of the loco.

There will be a 4-way connector between the loco and tender to connect the loco pickups and motor wires to the DCC decoder in the tender.