How I designed, 3D printed and constructed a Glyn Valley Third Class coach

Chirk station on the Glyn Valley Tramway is around an hour's drive from where I live in Cheshire and so I have visited the site of the railway many times (eg see https://ngruk.blogspot.com/2012/05/glyn-valley-tramway.html ). I love the railway's quirkiness and the fact it had a healthy range of goods traffic for most of its life. I can forgive the fact it wasn't 3 foot gauge as at 2' 4½" it was heading in the right direction from the almost default 2' gauge of most Welsh narrow gauge railways.

Chirk Station on the GVT with coaches. Source: NGRS Collection

After an experiment with designing, 3D printing and constructing rolling stock for an abandoned 0-16.5 project (see Progress Report 94), someone enquired as to whether the 3D drawings I had produced could be rescaled to 16mm. Never one to resist a challenge, I had a go - and this is part of the outcome (see also How I constructed a GVT Beyer Peacock loco)

The parts for the coach were drawn in TinkerCAD - my preferred drawing package partly because it's free to use, partly because it produces files which are guaranteed to print successfully on a 3D printer and partly because it is easy to master. The disadvantage is that it is only available online and sometimes (presumably because of heavy usage) it is slow to respond.

All the parts needed to construct the coach are available as free downloads on the GardenRails.org forum. It is available in various formats - 15mm or 16mm scale, 45mm or 32mm gauge, with or without moulded door handles and grab rails, single layer or multi-layered sides (to enable the glazing to fit between the layers) and side frames for pinpoint axles or roller bearings.

In this post, I am describing the way I constructed a version with single layered sides.

Firstly, the sides were glued to the floor. I used PLA filament bonded with High Viscosity Superglue from Tool Station.

Next, the ends were glued into place.

As you can see, the ends overlap the sides at roof level.

The underframe was fixed into place next. It tucked in behind and lined up with the ends of the headstocks. It was important to check that the recess for the brake gear was positioned on the same side as the brake lever on the end of the coach.

One side frame was fitted next .......

.... and the wheelsets inserted into their sockets before the second side frame was added. I used Bachmann metal 24.5mm diameter wheels for this coach, but I have also used Binnie 24mm diameter curly spoked wheels which are the correct pattern for these coaches (and cheaper). 

Note: If Binnie wheels and axles are used, then it is advisable to insert 4mm OD brass tubing into the sockets for the axles as the Binnie axles are slightly shorter. The brass tubing also acts as an effective bearing.

The brake gear was then added to the recess. As you can see, it slots into place.

The steps were then added to line up with the door openings and two roof sections were glued together and placed on top of the coach, with the oil lamp housing glued into the middle.

Four seats were then assembled, ........

[Awaiting photo]

..... and glued into the coach together with the partition wall.

The coach was then given a couple of coats of Halford's grey primer from an aerosol rattle can and the exterior painted either in Rover Brooklands Green (for the 16mm scale coaches) or Rover Burgundy Red (for the 15mm scale coaches), again using Halford's rattle cans/

The undercarriage was painted with black acrylic paint with a small amount of talcum powder added to give a matt finish. The door handles and grab handles were picked out with gold acrylics and the steps painted brown.

A couple of coaches were constructed from the sides without the moulded handles and so the door handles were brass castings from Brandbright and the grab handles made from 1.5mm brass rod.

Additional metal work such as the end steps and brake lever were picked out with black acrylics

..... and Burgundy Red coaches were given PLR crests printed on self adhesive vinyl printer film. 3D printed buffers and my own pattern of couplings were also added.

I have not, as yet, had an opportunity to run the coaches in a train. I will probably sell the 16mm scale coaches on eBay as it was only when I had printed a couple that a friend pointed out that most of my other rolling stock is constructed to 15mm scale (to give 3' gauge on 45mm track).

Some coaches have brass tube bearings, some have no bearings and some have roller bearings. Until I have had a chance to run them together, I cannot say which I prefer.