In many ways my NSWR Z20 project is a test bed for something I’ve been building toward for a number of years, building an O-scale steam locomotive. I’m not a complete beginner when it comes to scratch-building: I built a diesel many years ago using an Atlas O locomotive chassis as the base of that project. I’ve also built quite a few kits of steam locomotives over the years and the skills developed in doing so are a great basis for building a locomotive from scratch.
Recently I’ve done a few modelling tasks that were a bit of a test run for this project, the chassis rebuild of Pioneer being one of these. I wrote about this project on this blog earlier in the year. This small chassis building project acted as a great primer for building the much bigger chassis of the Z20 I’m working on now. I could have built the Z20’s chassis without tackling Pioneer’s much-needed upgrade first, but it did allow me to try out a few ideas and build up my level of courage to tackle the bigger locomotive. I also tackled a few simple milling projects earlier this year that allowed me to develop skills with this machine. I discovered that while you can buy the machine, read some books and watch any number of YouTube videos, nothing beats actually doing a few jobs to test your ambitions. A bloke by the name of Luiz Ally from South America is absolutely phenomenal and well worth a look.
This locomotive may be a scratch build in many ways it’s also a kit bash as it’s going to include quite a few parts from the Century Models 19 class kit which is still available from ModelOKits, So in this sense it’s still not a fully fledged scratch building project and still qualifies in my book as a stepping stone toward a fully scratch built locomotive. While a half-dozen or so modellers have told me over the years that the Century kit could act as the basis of a 20 class loco I must admit that I don’t know of anyone who has done this scratch/bash project. After getting this far with it I can understand why. There are some parts from the 19 class kit that can be used above the footplate in the construction of a 20 class locomotive, however unless you’re really up to scratch building a new chassis the conversion is not in the category of what I would describe as “easy”. Aside from the scratch built chassis I will need to build a cab, the main tanks and the coal bunker from scratch. The only parts I can use directly from the kit are the smokebox, boiler and firebox assembly and even here I might do my own thing because the boiler supplied with the kit is a smaller diameter than the real thing.
After my riveting experience with the bogie side frames I decided that I really needed to put some work into improving my riveting skills. As is usual with me I blamed my tools and decided to get a rivet press from the UK that I’ve had my eye on for a while. This new rivet press is from GW Models and it comes with an X-Y table, unlike my NWSL riveter I already own. I can’t provide you with a link for the GW Models web site because they don’t have one, and they don’t have an email address or credit card facilities either. However I’m assured by a friend in the UK that the tool is well worth the fuss of getting it and as such I’m waiting with bated breath to get it in my hands. This s likely to take a couple of months as it needs to be manufactured. Because this press will allow me to rivet lines square to each other using the X-Y table, and it also has a proper way to hold the work piece securely as the riveting is carried out (rather than holding the work piece with masking tape as I do now on my NWSL riveter) it should make approaching the riveting of the side tanks on this loco project a lot less stressful.
However, in spite of throwing more money at acquiring new tools, something I rarely need very much encouragement to do, I can’t wait till December to get on with building if I’m going to have any chance of getting a free lunch, so I looked at the next step I wanted to take in building the 20. The logical next item would be to build the pony truck at the front of the loco, however I need some brass tube of a particular diameter for this and it will be a week or two before I can get to Brisbane to buy what I need. In the interim my brass supplies from a couple of Melbourne model engineering companies arrived in the mail this week so I decided to make a start on some of the bits and pieces that hang off the side of the chassis. I spent most of today making the small air tanks that sit above the rear bogie I made last week.
The tanks I built today are really the first “scratch built” detail parts I’ve made for this project. The reason I’ve made them is that they aren’t available as separate items from a supplier and there’s nothing in the 19 class kit that would work as a stand in. What I’m most pleased about is the straightness of the rivets. Each tank is built up from five separate pieces of brass and covered in a thin sheet of brass shim (.003″) that has had the rivets applied prior to being soldered in place. I’ve made them a little narrower than the prototype (by about 1mm) quite deliberately, so they don’t stick out quite as far from the chassis as they should, because I’m more concerned about them sticking out too far than sitting a little bit further in than they should. I can live with them being a little too far in from the edge of the footplate but I couldn’t abide them sticking out like the proverbial. In my mind I toyed around with several different methods of retaining the tanks to the chassis but in the end I went with soldering them in place. A tricky operation, with the possibility of everything separating into a small pile of constituent parts, but it all worked out fine in the end. They both need a couple of little parts added (a top bracket and a spigot underneath) but these can be made and applied later.