Wednesday, July 30, 2014

Canopus: Cab Sides

It's amazing how quickly sheet brass can start to roughly resemble a steam engine It's also amazing just how frustrating soldering four pieces of brass together can be.

The first job, as with the footplate, was to punch out the rivets which this time caused me no issues at all. Next up was the four handrails at the sides of the cab doors. These are made of wire soldered onto the rear of the sheets. I fitted these while the sides were still on the fret to give me more to hold on to, and they were easy to fit with a dot of solder cream at each point.

Once cleaned up the two sides of the cab slot attach to the footplate via three tabs/slots and can be tack soldered into position. Figuring out how to keep these vertical while soldering from underneath was a bit of a challenge, but once I'd figured out what to use to support the pieces, actually securing them in place as easy. Attaching the front of the cab was also nice and easy, but the rear was a different story altogether.

The back of the cab isn't a single vertical piece but contains a step (two 90 degree folds) that form the inside edge of the coal bunker. The two folds are nicely half-etched and I scored them a couple of times to help make a neat fold and then folded the part. Unfortunately I don't think the half-etch marks are wide enough, given the thickness of the brass, to allow a 90 degree fold. I could get close but when I test fitted the part it was clear that the small difference was enough to make the part too tall, which in turn would mean the cab roof wouldn't fit. If I'd realised the problem in advance I might have been able to widen the etch mark slightly, but the problem is that once folded you can't really unfold the part without risking it splitting. I tried to apply more pressure to force the fold but it wouldn't fold far enough. In the end I must have applied slightly too much pressure as it split in half along the bottom fold line.

While I wouldn't recommend breaking the cab rear into two parts, once I found my self in this situation it was actually easy to fit. I simply soldered the bottom part in place, and then soldered the top part making sure it lined up with the roof properly. This has left a slight lip at the front of the step on the inside of the cab, but nothing you will notice once the model is finished; it may even help keep the drivers tea cup in the right place!

The other thing I've fitted, which you can't see, is a nut inside the coal bunker which will be used later to secure the chassis to the footplate. The next step is to roll the rear of the coal bunker and according to the instructions this requires annealing (with the help of the kitchen cooker) the part to help roll it to the right shape.

4 comments:

  1. Looking good already. This is one kit that I fancy having a go at myself.
    I always run a square needle file along any half-etched lines that need to be folded to 90 degrees. A fillet of solder along the inside of the bend adds strength.

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  2. It is fab progress and already starting to take on the character of the prototype!

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  3. That's looking really smart.

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