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.

How I constructed a Clogher Valley Railcar from an etched brass kit

 

Ever since I can remember, I have been attracted by the Walker railcars which ran on the Clogher Valley Railway and the County Donegal Railway. In particular, I like the first Walker Railcar which ran on the Clogher Valley and later on the County Donegal as Railcar No. 10. It is now preserved in the Ulster Folk and Transport Museum near Belfast.

Source: https://en.wikipedia.org/wiki/Ulster_Folk_and_Transport_Museums#/media/File:
Ulster_Transport_Museum,_Cultra,_County_Donega_Railways_Joint_Committee_Railcar_No_10.jpg

Whilst visiting the Llanfair Garden Railway Show a few years ago, I stumbled across a chap exhibiting 16mm scale models of various CDR railcars, including No. 10. When I asked about it, he informed me that it had been constructed from an etched brass kit supplied by John Campbell. Furthermore, he told me that John was also at the Show, exhibiting some of his crane models. I tracked John down and discovered that he no longer marketed the kit but was prepared to send me the brass etches without the accompanying whitemetal and resin castings. A few weeks later the etches arrived.

I regret to say that I put them into storage for a couple of years - partly because I was busy with other projects but also because I had never previously constructed a brass etched kit and felt somewhat daunted by the prospect. However, eventually, I plucked up courage and made a start. Various web sites and YouTube video tutorials had persuaded me that soldering together an etched brass kit was no big deal. So, nothing ventured .........

The first job was to separate the multitudinous parts from the frets - which in the intervening period had become tarnished.

This was achieved with the assistance of a mini-drill and slitting disk. The other methods which had been recommended on the various online tutorials didn't really work - possibly because the gauge of brass sheet was thicker.

The parts were cleaned up with various grades of emery papers and elbow grease.

As there were no instructions with the kit, I had to figure out what each part was and what it probably should be joined on to. I decided to start with the power truck. There were fewer parts and most seemed to be readily identifiable.

I had bought a motor bogie from G-Bits which had been specially modified for use under various Walker Railcars. Although it wasn't quite right in terms of wheelbase and wheel size for No. 10, it was close enough to save me the effort of creating a mechanism from scratch.

The running plate for the power truck was identified and it looked as if the slots for the side frames were provided for either 45mm or 32mm gauges.

The side frames needed to be modified .......

..... to fit over the axles and mouldings of the motor block, ........

...... before being soldered to the running plate.

The soldering turned out to be a lot easier than I had expected. a 75 Watt soldering iron, together with liquid flux painted on the joint and non-cored solder made the job almost idiot-proof (almost!).

The ends of the chassis were fitted next .......

...... before the assembly was test-fitted on the motor block.

All seemed well and so the parts for the superstructure were identified and dry-fitted into place. I wanted to find space under the bonnet for three 18650 li-ion cells. Whilst I could readily fit two cells into the engine compartment, there was insufficient space for the third.

However, I figured that if I modified the front and side of the cab, I could squeeze the third cell in. Scrutiny of photos of the cab interior of No. 10 showed that there was a similar intrusion into the cab space on the real thing, presumably to provide space for the diesel engine.

The parts for the superstructure were now soldered together.

As you can see, my soldering in tight corners is not the prettiest but I worked on the principle that I would prefer there to be too much solder rather than too little. It's not too much of an effort to tidy up the joints with a file and emery afterwards.

The three li-ion cells now fitted snugly inside the bonnet.

As no whitemetal or resin castings had been supplied for the bonnet lid, I needed to make my own. I decided to carve the curved shape from a piece of basswood, ....

.... using one of the riveted brackets as a template for the curve.

Battens were glued to the underside of the bonnet lid to align it so it could be removed to gain access to the battery pack.

The back of the cab and the remaining side were now soldered into place.

At this stage, I decided to detail the interior of the cab, using a couple of photos of the real thing as a guide. The parts were made from 1.5mm thick plasticard.

..... with paper clips and mapping pins for the various controls.

The driver had some drastic surgery performed to put one of his arms in the right position.

At this stage I decided to install the main wiring loom. The tagged lithium cells (from Ecolux) were wired-up to a 3S battery protection board .......

.... and a wiring loom for the switch and charge socket was soldered together.

Holes were drilled into the corner of the cab for the switch and socket, ......

..... which were then fixed in place .......

..... and disguised with a plasticard box.

The rear door of the cab .........

..... and interior roof sections came next.

These were probably the fiddliest parts to solder into place. Their positioning was critical but they were too small to be held in place with fingers and I couldn't find a reliable method of clamping them in place. In the end, I used a heat-proof oven glove to hold them whilst they were tacked at intervals with solder. Once the tacking was completed, I was able to follow this up with a more continuous fillet of solder.

The cab roof was made from three layers of basswood, ......

..... glued together, ......

..... roughly carved, .........

..... sanded smooth..........

...... and filler applied before being sanded again.

I decided to install the Deltang Rx65c receiver and Dallee Railbus soundcard into the roof and so carved out a cavity large enough for both.

The headlamp was made from a Garden Railway Specialists whitemetal casting, .......

..... hollowed out with a drill bit ........

..... with a 3mm warm white LED wired into place.

This was mounted on the cab roof and wired up to the front light output from the Rx65c.

The buffer beam was added next, .....

..... followed by the radiator which was made from a piece of a couple of pieces of 5mm foamboard with Plastruct rods forming the grille.

The exterior was given a couple of coats of red oxide primer from a Halford's aerosol rattle can.

The chassis was then given a couple of coats of satin black from the same source.

The interior was hand-painted cream and chocolate brown using cheap acrylic paints.

The power truck was then taken outside and given a few test runs to make sure everything was functioning as expected.

It was now time to tackle the trailer car. The parts were separate from the fret, cleaned-up and identified by testing-fitting them together. 

The front end was joined to the floor, ......

..... before the 28 supports for the seats were soldered into place.

At this stage I was uncertain as to how I would construct the seats themselves as these would have been provided as resin or whitemetal castings.

No trailing bogie was provided in the kit and so I consulted photos to determine what sort of size it was supposed to be. I fished around in my bits-boxes and unearthed one which looked about the right size, though it was not of the same design.

The ends of the axle boxes were sawn off ........

..... and new side frames fashioned from 2mm thick plasticard.

The frames were glued to the old frames and the axle-boxes re-applied. A representation of the middle spring section was made from offcuts of plasticard and a raised pivot attached made from a piece of stripwood of the correct thickness.

The pivot socket was soldered to the base of the trailer ......

..... and the pivot socket for the front of the trailer attached to the rear of the power truck.

The trailer was then attached temporarily to the power truck and tested over some of the more demanding curves on my railway to ensure that it would cope.

Some slight adjustment was required to increase the clearance between the insides of the front end of the trailer and the wheels, but apart from that the trailer and its bogie were remarkably well behaved.

The sides of the trailer were tackled next. 

The lower halves of these needed to be curved to form tumblehomes but fortunately, the doorway and rear section provided a useful template.

The rear of the passenger compartment was a bit of a struggle to attach. I'm not certain I got it right but I assumed there was a recess at the corners to allow preformed resin or whitemetal curved segments to be inserted.

These were formed, through trial, error and improvement, from pieces of basswood. I think it was the third attempt before I got a shape which seemed to fit.

Even then, a fair amount of filler was needed to hide the gaps.

The roof of the trailer was formed in a similar way to the cab roof, from three layers of basswood.

The rear section of the roof was the trickiest as it curved in two planes. Similarly, the lower section of the rear needed a double curved chunk of basswood to be carved. As you can see, filler came to my rescue once more.

The steps were soldered together and fixed to the rear of the trailer.

The trim along the sides of the trailer was attached, .......

.... as were the vertical strips.

Again, the castings for the window vents hadn't been supplied and so .......

..... they were carved from 2mm thick plasticard ........

..... and glued into place with thick (High Viscosity) superglue.

The luggage rack was soldered together and glued to the roof.

After some more test running ......

.... the trailer was given a couple of coats of Halford's red oxide primer.

At this stage, I decided some enhancements were needed. Firstly, when comparing the model to photos of the real thing, I noticed that the window surrounds on both the cab and the trailer needed to be thickened. Pieces of 2mm thick plasticard were cut to size and glued into place inside the trailer .....

..... and the cab. The driver was replaced as the head of the original driver kept interfering with the soundcard.

The photos revealed that the trim on the trailer also extended around the cab. None seemed to be supplied with the kit and so it was manufactured from strips of 1.5mm and 1mm thick plasticard and glued into place.

Sand-boxes were made from offcuts of 5mm thick foamboard .....

.... and glued to the side frames of the motor truck chassis.

[Awaiting photo]

Lighting was added to the trailer car with some LED striplights wired up to one of the switchable  outputs from the Deltang Rx65c receiver.

And finally, the problem of how to make 28 identical seats was solved by learning how to draw 3D objects with SketchUp and buying a cheap (£70GBP) 3D printer.

The railcar then entered the paintshop for its final livery of Halford's Rover Burgundy Red, PLR crests were added to the sides of the cab and trailer and glazing installed in the windows.

3D printed baggage was added to the roof rack  and the roofs hand-painted dark grey with cheap acrylic paints.

The steps were thickened with 2mm plasticard and painted brown and handrails added beside the doors made from brass rod and handrail knobs from GRS.

The railcar was then given some extensive testing.

After a couple of months, I decided to replace the Dallee Galloping Goose soundcard with something more appropriate - a MyLocoSound railcar soundcard - the cavity in the cab roof space was enlarged to accommodate it.

It may have taken me a while to get around to it, but I am pleased I bit the bullet and had a go at constructing the railcar from a brass etch kit. I learned a lot in the process. For me, the advantages of a brass model are that the parts can be joined almost instantaneously and easily removed or re-positioned. The disadvantages are that I would have to construct a few more kits before I can claim to have mastered the construction process. Also, some parts such as the window frames and steps needed to be thickened with plasticard to ensure they were realistic. Maybe the full kit included the parts needed to achieve this but it seems to me that constructing the model from plasticard would have obviated the need for this additional step.

However, I am delighted I now have this model pootling about on my railway. Though it has highlighted an important discrepancy. Neither of my termini have turntables and so I need either to construct them or to provide the railcar with a mate coupled back to back as they did on the Isle of Man so they can run in both directions. I am seriously considering constructing the CVR Walker Railtruck with a non-powered bogie so it can be towed behind the railcar. If the non-powered bogie can be swapped for the motor block on the railcar (as indeed happened on the CVR), then I will be able to run the railtruck on its own occasionally - though the turntable problem will still persist.