Wb 1 - Wubbada Wubbada

In which DB contemplates his first steam loco model (this long-maturing blog entry was written in September 2024, had its genesis in late 2023, and is in mid-2025 almost ready to go...).

I have always been a diesel man, as that's what I've grew up with, but if there is one place I'd like to go back to in a time machine, it would be the West Coast in the late 1950s-1960s. A magnificent collection of ancient engines with jaunty little trains of four wheelers running through bush scenery and over rickety bridges to remote coal mines on wobbly branches to places with funny names like Blackball/Roa, Dunollie/Rapahoe/Rewanui, Conns Creek and so on.

When we decided to come back to NZ in 2015, I had visions of making a small Rewanui module to get back into NZ120. I bought a couple of Bachmann 2-6-0 locos in anticipation (underpinnings for a Wa and Ww maybe), and when we were in Wellington looking for a house, I started making a relatively awful Q hopper wagon on a Peco 10 foot chassis, but that was a very short-lived attempt to return to NZ120. After that, we were away for a while, and Swiss Z scale won my heart for a few years.

In October 2023, I came back to modelling after a few years off. Press-ganged into operating the massive 9mm layout at the Christchurch show, I spent the whole weekend running a small train around (and around and around) with a Wb. The loco was running backwards the whole time because only the headlight on the bunker end worked, and because it seemed to run better that way without derailing anyway. Both were handy excuses, because I secretly prefer the aesthetics of a tank loco or a Dsa running backwards. 

Delving further into the aesthetics of tank engines, I have always preferred the looks of the W, Wa and Ww, so have never paid much attention to Wb locos, but this big 9mm model won me over. The other train that was running for most of the time was an Ab with a couple of red wooden carriages and a matching car-van.

So, when it came time to try out 3 foot 6's 3D printed goodies, a Wb, two carriages and a car-van accidentally fell into the shopping cart in late 2023. 

This is one of the Bachmann N Alco 4-6-0 chassis mentioned before, by the way. 

Even longer ago I bought a couple of metal spoked wheels in Europe, filed the pinpoint axles off one and put it into the leading truck of the other loco, before taking the rest of it to pieces. There is a decoder in the tender and all tender wheels have pickups. Hmmm. Lets put that aside for now.

Below is the raw Wb print. I have yet to straighten out some bowing in the side tanks.

It's not a bad shell as-is. Certainly 'good enough to go', but I might make a few wee improvements and additions. 

• Some of the polygons on the cab roof and domes and funnel can be smoothed off
• The main thing that looks a bit skewiff is the funnel and the WHB pump exhaust pipe behind it.
• The handrails could optionally be replaced with wire, as could the front boiler stays, although they don't look that bad. 

The first challenge is seeing if the shell can fit on my available Bachmann chassis. The slide and connecting rods were removed off the printed shell first, and then a Dremel arrived to attack the lower boiler between the cylinders before I could stop it. The piston/valve chest bits were accidentally knocked off when I tried to thin them from the inside to fit over the chassis' cylinders, but I have saved these and will stick them back on later.

After a few goes with a sanding drum and then a cutting tool, it fitted! The wheels will probably sit a mm or so slightly further forward than in the pic below, and the whole top a smidge lower on the chassis. The front truck obviously needs to be extended further forward, and a rear one made.

As for the suitability of the chassis, the driving wheels have a few too many spokes and the three axles aren't perfectly spaced, but you might not have noticed those two things if I hadn't told you. It also has fancy Walschaerts valve gear, whereas the Wb has inside Stephensons. Dammit. It seems a shame to lose this, but needs must. I'll save that job for another day. 

In the meantime I can hack at the top with my ever-deteriorating eyesight. I chipped off the integral  WHB exhaust pipe behind the funnel carefully with a knife, and tried slimming and shaping the funnel a little with a jeweller's half-round file. This was not as easy as it sounds because this resin is really solid. That is a good thing. It took a phenomenal amount of force with a file to accidentally knock the generator exhaust off. Which is a shame, because that was nicely done...

Drilling out the funnel was done by hand with a drill bit, then a pointy file and then this odd Dremel attachment (above) in the fingers, so that has produced a more pleasing look. The funnel and domes could do with some 'flare' where they meet the boiler jacket, which could be done with putty, but I think I'd make a dog's out of it in the tight space. I think I'll leave it be. 

• I also drilled and filed out the cab roof vent (somewhat badly, according to this image) so it can be modelled half-open (which it could have been without opening it up really) and thanks to the solidity of the resin, I was able to... 
• remove the rear handrail with a sanding drum (without knocking off the brake hose), 
• remove the tank-top handrails with a Dremel wheel (while leaving the pegs intact!), 
• thin the rear steps with the Dremel without knocking them off (this is solid resin!), 
• remove the rear light shroud, 
• thin the flat plate under the smokebox that holds the headstock, 
• round the corners of the headstocks a little, 
• knock a little off the top of the steam dome, 
• and drill a bunch of holes for handrails, piping, and that generator exhaust. 

And that's about it. I probably should go back and try to thin out the chunky sheetmetal at the top of the bunker that I've just noticed. I'll bet I've forgotten that by tomorrow 

(which I obviously did, because this is being posted nine months later...) Funnily, I've since built Elmer Lane depot and could do with a steam loco...