Canopus: Chassis Detailing

So, as a number of people pointed out in the comments to the previous post, the problem with the guard irons wasn't that they were too long, but that I hadn't bent them to shape. Embarrassingly that was the next step in the instructions. As you can see though the chassis has moved on a little further than the guard irons.

The main chassis etch contained the outline of the springs but no detail other than a few rivets. Al the details are provided by overlays. The first job was to ream out the holes in the axleboxes so that they fit around the protruding bearings before they were soldered to the side of the chassis. Once they were fitted the spring detail etches were filed to to fit and then soldered in place.

The next step solder the rest of the chassis retaining parts in place, which means that the wheels will be permanently trapped between the outside frames. I'm currently debating if it is worth trying to add the remaining details to the chassis first so I can paint it without risking bunging up the wheels and moving parts, but the consensus seems to be to finish the model first (at least to the point of wheels, pickups, and fly cranks) and then paint it. If anyone has any thoughts though I'd appreciate any suggestions.

Canopus: Fouled by the Guards

While I'm still working on all the detailed fittings for the main body of Canopus I've now also made a start on the chassis. Currently I've soldered the six bearings for the main wheels in place and folded the chassis so I can test fit the wheels. While this was nice and straightforward it has highlighted one problem with the kit.

Most steam locomotives were fitted with guard irons, metal protrusions in front of the wheels, which are designed to knock away small objects from the top of the rail surface which, I guess, helped to prevent derailments. The guard irons on Canopus are easy to see in the photo taken when in use by the RAF. In that photo they appear to end just below the level of the wheel axles, but this isn't the case on the kit.

As you can see the guard irons are unbelievably long and end well below rail level. Fortunately as they are part of the frames on the kit (rather than inline with the rail) they will allow the chassis to sit flat on the track. The problem is that I want to be able to run the loco on a layout where there will be a section of the track set into a road surface at which point the guard irons would be below the level of the road. Clearly this is a mistake in the kit so I'll have to file them back to a more appropriate length. On the plus side the chassis seems to sit perfectly flat on the rail and a piece of glass and the wheels turn freely which suggests I got the bearings in straight (although I did file down the flanges slightly as the clearances were a little tight).

A Rake of Wagons

So work on Canopus has slowed slightly, mostly as we spent the weekend at a family wedding. Having said that I have done some work on the model that I haven't blogged about yet, but I'd like to be able to explain what some of the parts are supposed to represent so I'm doing a bit of reading up first before I show you those.

So to keep you entertained I thought I'd show you the completed rake of three of the box wagons I recently printed.

As you can see the wagons don't currently have couplings fitted. I'm thinking of only fitting working couplings to each end of the rake and to permanently attach the three wagons together, but has anyone any suggestions of a good way of doing this? I have the slot in the buffer beam for the Greenwich coupling so can easily attach something else in the same place, but what would work best?

Canopus: Fitting the Boiler

After a fair amount of filing and fettling I thought I was happy with the boiler, smokebox and saddletank castings. Turns out it still wouldn't all fit together properly.

If you remember back to the previous post on Canopus I mentioned in passing that the smokebox needed a hole drilling and tapping but that "this was easy to do as there is a dimple in the casting to aid correct positioning". Unfortunately I didn't actually check the dimple was in the correct position before drilling and tapping the hole. It turns out that the dimple wasn't correctly positioned on the casting so when the smokebox was screwed to the footplate it was about a millimetre to the right of centre (when viewed from the front).

Now a millimetre might not sound like much but on a model that is only 26mm wide it is quite a lot. What is more annoying is that I didn't spot the problem during the numerous test assemblies I did, only after the parts were glued together did I spot that they were out of line.

At first I thought I could live with the problem, but the more I looked at it the worse it seemed. Fortunately it was easy to break the two superglued joints to allow me to separate the parts and refit them. Unfortunately there was no easy way of moving the tapped hole in the smokebox casting. If it had just been a hole I would have filled it and drilled a new one, but I wasn't sure if that would work. Instead I slightly opened up the hole in the footplate that the screw passes through allowing a better positioning of the part; I will need to do the same to the matching hole in the chassis at some point.

With the boiler fitted, I attached the chimney and smokebox door handle (both of which are nice brass castings) although from these photos there is clearly still some work to do to hide the join between the chimney and smokebox, but I'll do that when I've finished the rest of the body. Currently the saddletank is only rested in place as I need to drill holes in it for handrail knobs etc.

It may have taken a while to get right but it is now looking like a really interesting little steam engine.

Aberllefenni Box Wagon

Getting the boiler to fit on to Canopus correctly is taking a little longer than expected, and as I received another batch of test 3D prints at the end of last week I thought I'd switch focus and show you my latest piece of 3D printed rolling stock.

While flat wagons and three bar slab wagons are great, most things I'm going to want to portray on a layout set in Yorkshire are (I think) more likely to need to be carried in a wagon with sides, so here we have a simple box shaped wagon. Whilst it may look at home on my layout (whenever I actually get around to building it) the wagon is actually based on wagons that were in common use in the Aberllefenni Slate Quarry in Wales. It is a fairly accurate model (it's ever so slightly too wide so as to accommodate the wheels) as it's based on a scale drawing in the Slate Quarry Album by Gordon and Ann Hatherill.

I was a bit worried that the axle boxes would be too fine to print properly but they have come out really well and the wheels turn really well in them so even unweighted they seem to run along the rails nicely. I definitely think I'll be printing a bunch more of these and if you happen to want any then, as with most of my 3D printed models, head over to Penistone Railway Works where I'll happily sell you some!

Canopus: Retubing the Boiler

While I never expected that the kit for Canopus would be easy to put together, I hadn't expected to hit quite so many issues as I have so far. Prior to this post I had used six etched parts, one of which I broke and one of which I destroyed and had to replace. Rather foolishly I hoped that the next step would go together easier.

Having assembled the cab the next stage involves fitting the smokebox, boiler and saddletank. This actually involves four parts as the boiler consists of a brass tube and a cast whitemetal weight. The other two parts are also whitemetal castings (the kit includes both a cast and etched saddletank but I'm using the cast version as it is heavier). The bottom of the smokebox needs a hole drilling and tapping to take the other fixing screw (the first one is at the bottom of the coal bunker) that keeps the body attached to the chassis. This was easy to do as there is a dimple in the casting to aid correct positioning. Having test fitted the smokebox to the footplate I found that the boiler wouldn't fit.

The problem, as you can see from the first two photos is that while the instructions say that the saddletank "should be a snug fit against the cab ... so that it just touches the smokebox" both the boiler tube and weight are longer than the saddletank casting. The solution is easy, although rather time consuming.

First I used a razor saw in a small miter box to trim the brass tube to a more acceptable length, before then filing it to an exact match to the length of the saddletank. I then filed the whitemetal weight down until it was the same length as the brass tube. Having test fitted the parts they do fit although I haven't yet had the time to actually glue and solder everything into place so that will (hopefully) be a job for tomorrow.

Canopus: Cooking the Coal Bunker

Having added the four main walls for the cab the remaining piece is the back wall of the coal bunker. This is made from a relatively small piece of brass which needs to be rolled to match the profile of the rear edge of the cab sides. While this should be an easy piece to fit, it isn't. The problem is that given the thickness of the brass and the size of the part it is almost impossible to roll it to the right shape. The trick, apparently, is to anneal the brass which should make it easier to shape.

Annealing is basically just heating the metal to make it easier to work and the instructions say that you can do this by simply placing the part on an electric cooker hob for about 10 minutes. Unfortunately we have a gas cooker and I wasn't sure how I'd support the part in the flames, so instead I decided to use another item from the kitchen, a blow torch. Usually the blow torch is used for melting the sugar on top of a creme brulee or this excellent Lime and Passion Fruit Tart, but I thought it should be able to heat the brass well enough so I set up a sensible looking work area and turned on the blowtorch.

Now the blowtorch did seem to be able to heat the metal quite well, although even after about 10 minutes it wasn't exactly glowing, but then disaster struck as the metal appeared to bubble; I'm guessing I held the torch in the same place for two long. You can see the ripple marks on the bottom left corner, and there is also a bubble on the back in the middle. So while the part now bends much easier it wasn't really useable.

Fortunately I'd decided to measure the part (10.75mm by 23.5mm) while it was flat before I tried annealing it, so I made a replacement using some 0.25mm brass sheet from Albion Alloys. This sheet is slightly thinner than the part from the kit, but not noticeably so, and can just about be formed without annealing. I gently rolled the part using the handle of my modelling knife and then soldered it in place which definitely transforms the look of the rear of the cab.