I am building a second kit for a BYA covered steel wagon. This post follows on from my first attempt, which came out reasonably well but rides too high on its bogies. The details on this model are far too fragile too.
1. Detail parts fret (29 November 2019)
I have started the second model with the fret for the detail parts. This is etched from 0.2 mm (8 thou) brass and some of the parts are half-etched into this, so the details have the strength of kitchen foil. They bend every time I look at the model, let alone pick it up.
The model needs four handles and four sets of steps. The fret has four handles and six sets of steps. So, I have taken the four handles from the first kit and soldered them back-to-back onto the four new handles. This is easier than it looks, I used a Peco track pin to align the holes. Then I backed up the four sets of steps with the spares from both kits.
The results are hugely stronger than the originals, and any excess thickness is not going to show after cleaning up and painting:
The next step is to sort out the ride height and make sure the model can still go round my trainset curves.
2. Lowering onto bogies (30 November 2019)
I have lowered the chassis on its bogies, and the model successfully negotiates radius 2 and even radius 1 curves:
The work involved removing all of the moulded resin mounts and inserting M2 threaded bushes. Here is one of the bushes before finally tapping it home:
With the chassis sitting at a scale height, the wheels are of course inside the solebars and not below them. The solebars and wheels are much thicker than their scale thicknesses, but the wagon would still go round a radius 2 curve. I cut away some patches on the insides of the solebars to let it go round a radius 1 curve too.
This is very important to me, because it proves that I can make a British outline bogie wagon, able to negotiate a "trainset" curve, in 1:87 scale, without any obvious adjustments to the width of the model. The major RTR manufactures have been doing this for years - good examples are the Night Ferry coaches from LS Models and ferry wagons from Roco - but these manufacturers have the advantages of CAD systems and the ability to fine-tune their designs before they go into production.
The chassis seems to run reliably in its "push along" state without proper bogie pivots and is even more free-running than the first attempt at the kit. When the NEM pockets go in these will be at their usual height and there may be problems with their couplers fouling the undersides of the buffers. I'll have to watch out for this, but fundamentally this second kit looks like it can build into a scale model able to run on my layout.
What I would like to do now is to work up the resin 'cover' (the body) and the chassis as two separate assemblies, so I only fit them together near the end of the build.
3. Buffers (1 December 2019)
I managed to destroy all of the buffers of the first kit during the build. This led me to take the buffers from this second kit to finish the first kit.
I have had a go at making some new ones. These are from 1/8 inch styrene tube with the bore opened up to 2 mm. There are short pegs from 2 mm diameter rod to attach the tubes onto the buffer beams, and patches of styrene on top of Electrotren buffer heads to represent the rather plain heads on the prototypes:
Full of enthusiasm I have fixed these onto the body shell. I'm not sure if this was sensible, because the couplers on the first wagon are very close underneath its buffers, and I've lowered the chassis for this second model. Time will tell.
I now have an Electrotren wagon without any buffer heads, but at least I can rob another Electrotren model to resupply it one day. Of course, at this rate I will always have one wagon without any buffers ...
4. Latch details (1 December 2019)
My build sequence for this kit is completely different to the approach suggested in the instructions, but it is working for me. My next step was to build up the latch details on the ends of the body shell. I will leave off the handles until near the end of the build:
I do not understand why some kit manufacturers choose to use such thin brass for parts. The brace is barely 0.1 mm (4 thou) thick and it will not stay flat, despite three goes at fixing it. It doesn't line up with the resin parts too well either, but fortunately this photo is a great deal larger than the model.
The next step has got to be, to add the coupler cams. I must fix these higher than I did last time, to clear the wheels under the lowered chassis.
5. Couplers (9 December 2019)
I am using Symoba cams because they are compact and it is easy to adjust the height of the NEM 362 pockets. These cams don’t have holes for mounting screws, so I set them in a bed of epoxy resin (Araldite). Please excuse me if this description is a bit long-winded. I will probably never build another kit for a British H0 wagon (no kits exist) so I may as well include all the details here.
I carved away the resin chassis casting to make room for the cams, and fixed them into place with tiny dabs of cyanoacrylate. The cams must go in “square”, with the spigot central to the model and truly vertical. In addition, there has to be enough space to let the coupler pocket swing between the nearest wheels but not touch their axle.
Then I added temporary dams to contain the Araldite. The dams are strips of styrene, held in place with double-sided sticky tape. The idea is, the Araldite sticks to the adhesive on the sticky tape, but far more strongly than the adhesive sticks to its tape, so everything peels apart afterwards.
I poured in enough Araldite to fill the voids around the cams and left this overnight to cure:
And then, with the Araldite nicely set, I peeled the dams away:
With the buffer beams fixed onto the cover moulding with patches of styrene sheet (step 3 above), the cover is a light interference fit onto the chassis. I don’t need to fix the cover in place, and I can experiment with different ballast weights one day.
I put the bogies onto the model with a couple of temporary screws and washers so I could set the height of the NEM sockets:
For a fully “correct” installation, the Symoba gauge (photo above) should be touching the buffer heads. I have a larger gap on my model to make sure the buffers do not touch on a 450 mm (radius 2) curve, and because I am using the Symoba ‘standard length’ NEM socket. If I had only larger curves, I could use the Symoba ‘short’ NEM socket. I cannot put the cam further inside the wagon because either NEM socket would then collide with the wheels on the bogie.
Finally, I gave the model some test runs. Even without a ballast weight installed, the model stayed on the track. With the NEM sockets at the correct height, there is just enough free space for my Roco universal couplers to swing below the buffers, and so the installation of the couplers is complete:
I now have the essence of a model wagon, needing only its proper bogie pivots, a ballast weight and the final details.
6. Completing the Chassis (10 December 2019)
The bogie pivots are to the design I devised for my first BYA wagon. The pivot is a gearbox bush fixed into the bogie frame, swivelling around a shouldered spacer made from 1.8 inch brass tube with a similar bush soldered on. For this second model there is a washer made from 0.75 mm styrene to set the final ride height:
The whole assembly is held together by an M2 screw tightened into the brass bush in the chassis:
The ballast for the model is about 50 grams of roofing lead. The lower strip is glued onto the chassis and the second strip is held by two M2 screws so I can remove it or add more weight if this proves worthwhile in the future:
The total weight of the model is 115 grams, close to the NMRA recommendation for a wagon of this length and equating to about 1 ounce on each axle.
The brake wheel and brake indicator are from the kit, with their backs reinforced with Araldite:
I added the horizontal strips below the solebars from styrene because the kit parts do not fit and are far too fragile:
It's funny how the camera reveals little bits I never thought were still there. In fact, the camera is a very useful tool before calling a model "finished".
The four foot steps are also glued onto the chassis:
Their tops meet up with the underneath of the cover moulding.
7. Completing the Cover Latches (10 December 2019)
My final task for the cover moulding was to add the handles for the latches and the second lengths of brass wire between them:
8. Finishing the Model (0 December 2019)
The cover moulding sits on top of the chassis. The cover is held in place by a light interference fit at its two ends and doesn’t need further fixing. This completes the model:
I am pleased with this, I feel I have made a truly scale model and it can negotiate a radius 2 or even radius 1 curve on my layout. I am not too sure about painting it, this goes wrong too often for me. At the moment I want to find someone who can paint it for me, though I accept I ought to be able to manage the primer.
It is probably best to just use the model on the layout for a while and to see how well it runs.