The project

Like many kids, I was keen on constructing plastic model kits, particularly of planes and Apollo era space vehicles. I also enjoyed scratch building models from cardboard.

As an adult, I kept making the occasional plastic aeroplane kit, but hadn’t pursued much in the way of scratch building. Being somewhat of a train fan, back in 2014 I thought I’d have a go at building a Victorian Railways era diesel locomotive from balsa wood. As a loco design with a minimum amount of curved surfaces, it seemed like a relatively easy shape to model.


Photoshop reconstruction of the X31 original builder’s plate. During the early 1980s, locos were fitted with radios and the builder’s plates were removed and replaced with ‘radio equipped’ stickers. The replacement builder’s plate on the restored X31 owned by Seymour Railway Heritage Centre has the Clyde model number G16C instead of X31 (image below). Click images for larger view.


There is quite a lot of good reference material on the web and in some rail magazines and books I have in my library, but the greatest source of reference was the Seymour Railway Heritage Centre. They own the X31 and have restored it to operational status, regularly hiring it out to commercial rail operators. During the month of this writing (October 2020) it was spotted hauling cement wagons on the Dandenong line.

X31 at Seymour Railway Heritage Centre open day, 17 Oct 2015. Click image for larger view.

The X-31 was on display during the SRHC Open Day in October 2015, which provided a great opportunity to take lots of photos and videos. Open Day visits in years following have provided further opportunities to gather extra reference material, not from the X31, but from other class locos kept at Seymour, many of which share similar design features.

My balsa model 920 mm long. Long end, September 2020. Click image for larger view.

Modelling progress was slow due to life getting in the way (and losing interest for a while!) The basics of the model sat on the shelf for ages until covid isolation provided lots of modelling time; for both balsa and 3D printing.

Back in the early 2000s I had learned 3D modelling and animation as part of TAFE and Uni courses, using a program called Lightwave 3D. Although I spent a number of years as an architectural illustrator (using a mix of 3D created in SketchUp and Photoshop), my interest in 3D modelling had waned somewhat, but has been revived with the advent of 3D printing.

A few years ago, I bought a cheapish 3D printer from Aldi, and have used it to make mundane items including a window winder handle and bicycle ring gear chain guard, and recently parts for the balsa loco model. As the virtual parts are modelled in Lightwave (for 3D printing in plastic), it seemed worthwhile to model the whole loco in virtual 3D. So now I have two models – a virtual 3D loco, and a real world version of it made from balsa and 3D printed plastic parts.

The X class locomotives were manufactured in three batches by Clyde Engineering: Batches 1 and 2 at Clyde’s Granville, NSW workshops, and Batch 3 at their Rosewater, SA workshops. The design of the series was based around a General Motors EMD (Electro Motive Division) engine, generators and traction motors, and was given the Clyde model number of G16C.

The X31 was delivered to Victorian Railways on 15 August 1966 as the first of six locomotives in Batch 1 (X31 – X36). Batch 2 (eight locos, X37 – X44) was completed in September 1970, and the final, Batch 3 (ten locos, X45 – X54) were completed in June 1976. Some locos have been rebuilt and are operational as XR Class, but the X31 is the only refurbished and operational loco in its original VR livery.

Balsa 1:20 scale model 920 mm long. Short end, September 2020. Click image for larger view.


Pages (also accessible from dropdown menu above)

Balsa Beginnings
3D printed parts and Lightwave 3D
The (almost) Complete Balsa Model
3D Cab Interior modelling and painting
3D Virtual Model