The caboose is finished!

Finally, I finished the caboose. It was down to the wire to finish it before the big train show this weekend, but here you have it. Overally, I’m pretty happy with it.

Next up? Well, I’ve got a couple of non-P87 models under way, and I reckon I’d better finish them. Then, I’m hoping to start the big basement reno sometime this winter, which will pave the way for (drum roll please) the layout!

Stay tuned.

Caboose roof

Here you go, the roof is just about finished; there’s a little weathering to do, and perhaps a little patina on the smoke jack.

I thought for a long time about the covering. I think this was likely canvas, although I don’t have any proof. Once I’d decided it was canvas, I spent weeks looking for real evidence as to what a well-maintained canvas roof should look like. I’ve seen loads of models with tissue paper on the roof to represent canvas texture, as well as seams between sheets. I found a number of references and pictures on the web to restoration efforts involving canvas roofs, and found that these were universally made in one big piece of canvas. Once the canvas was stretched over the roof, it was then painted. So, are the seams on other models bogus? If you paint canvas, I wouldn’t expect much texture to remain, especially in HO scale.

The boards leading from the ladder to the running board are another supposition. If the roof was indeed canvas, they would have wanted to protect it from brakemen’s feet. However, in the good side view we have, I can’t see any evidence of a normal platform here.

The running boards are plastic, of course. You don’t paint running boards because it makes them slick. So, they are finished in my recipe for well-maintained wood: Humbrol matt 63 (sand colour) base coat followed by some dry-brushed matt 170 (dark brown) then some dry-brushed light grey, and finally a wash of dark grey. Like the underframe, I may start doing these in wood.

When the inevitable aerial photograph shows up shortly after the model is completed, I’ll probably wind up redoing much of the roof. But here it is for now.

Next step: I need to cut the bottom out of the cupola now that it’s glued down, and create an interior for the cupola at least. I hadn’t planned to make an interior for this model, but there are so many windows in the cupola, I don’t think I can get away with that.

Lettering still wet

I just finished doing the lettering. This is a dry transfer, which I had made by All-Out Graphics here in North Vancouver. The artwork was my own, of course. It’s not cheap for the short runs that I need, but I much prefer working with dry transfers, and they do a nice job.

We’re definitely down to the short stokes now! I cut a new weight this evening, and I expect I’ll install that along with the doors tomorrow. I’ll get my son to mix the epoxy for the weight — gotta get them hooked early.

Caboose steps

I hemmed and hawed for a while before finally getting down to making the steps. My initial thought was I would etch the steps as one of my origami etchings. Then, when the etchings didn’t work out, I figured it might be easiest to bend the two stringers from a single length of brass strip.

Finally, I settled on a more typical approach. After bending up the stringers on a simple jig, I placed them in two holes the correct distance apart. I soldered the top step on first flat against the block into which the two holes had been drilled. Then, I put the other ends of the stringers in the block and soldered the bottom step on, soldering them perpendicular to the block.

After all that pondering, it turned out to be a good deal easier to solder the steps up precisely. They wound up taking only about a few minutes each, and so, I made an extra.

To install, I had the most success when I blu-tacked a spacer strip to the side sill, and then held the steps against the spacer. The stringers are glued to the back of the sills, and I’m still pondering whether I should reinforce them with some sort of pinning.

Brakes mostly done

Here are the brakes almost completed. This is, I think the first time I’ve used turnbuckles to model the clevises. These are tricky, and I think I’ve decided the best thing to do is to glue them to the rods while they are still on the sprue, then cut them in half. You’d wind up sacrificing half the turnbuckles, but I think I lost that many to the dust bunnies anyway.

Etched trucks – the design process

A reader just asked with regards to my trucks,

“I’m most interested in your design process, how you first determined you could etch the truck sideframes in such a way several folds would complete the process, and then how you engineered the design. I’ll check out your blog and if I’m still confused I’ll email you again.”

To tell the truth, I thought about these trucks for years before coming up with this approach. I tried casting them in resin, but the sections are too small to cast reliably, and who knows what the performance would be like if you could get them to come out of the mold? I really don’t recall how I came up with the idea of etching them, but it was probably from reading too many British magazines.

I think the design probably started with thinking about how to keep the two axle holes the right distance apart. So, I might have started with a plate with the two axle holes etched in, planning to solder the arch bars to this plate, and then file away the excess once everything was solid. From there, it’s not a long way before you realize that the arch bars can also be etched and folded onto the plate accordian style.

The tricky bit, which stumped me for ages, was how to attach them to the bolster. In Proto:87, it is especially useful to have this all square. I toyed around with various ideas involving posts and holes in the bolster, much like some of the equalizing delrin trucks on the market. But, I could never come up with a satisfactory way of isolating the two sides. Finally, I realized that I could use the bolster much as the prototype did.

Once I’d figured it all out in my mind (I inherited very good spatial visualization from my grandfather), I drew it up in QuickCad. I didn’t know exactly how big to make the half-etched gaps for right angle and 180 degree bends, but I surmised that it must be something like the distance around an appropriate arc of radius equal to the 3/4 the thickness of the material. My laser printer only does 600 dpi, and so, that calculation is probably way more accurate than my laser printer is able to resolve anyway. It happens that the folds do come out crisply, so I guess I wasn’t too far wrong.

I then scaled up the design I forget how many times, and transfered the design to foam core for testing. I scaled it up sufficiently so the foam core was the right thickness to represent the final metal. This foam core mockup rattled around my basement for ages, but it seems to be gone now, otherwise I would show it to you. The mockup worked, and so, I started working in actual metal.

Now that I’ve assembled two pairs of trucks, I plan to completely revise the design before I make any more. The original design called for a half-etched bottom chord, which turned out to be too flimsy due to my unpredictable etching process. On the second iteration, I therefore changed the design to make the bottom chord full thickness; this was not a complete revision, and it turned out less satisfactory. The other failing is that the top two arch bars are only connected to one another at one end. This is a result of them being slightly different shapes. However, the difference is not noticeable at all, and so, I think I will connect them at both ends, and dramatically simplify the soldering process.

The rest, as they say, is history. Except in this case, it really is history because I’ve written much of it down somewhere.

Caboose underframe

This might be the last styrene underframe I ever do. There are two reasons: first they didn’t actually paint underframes, even on passenger cars. Second, making styrene look like wood is a nuisance, but making wood look like wood is a doddle. So the next project is going to try a wooden underframe again, and I’ll paint all the hardware before installation rather than after so I don’t have to deal with that either.

Even so, I think this is turning out reasonably well. You’ll have to wait until the lettering goes on to see the sides.