Small but big - the Motor Rail G-series in 7/8ths...

Well, it was bound to happen... the laser cutting experiment, combined with my plans to build some Hudson Hunslets next year both meant I needed to do some research. A chance conversation with Matt Nunn at the Llanfair show (he mentioned the Motor Rail Duplex) led me back to my Motor Rail book, and the G-series jumped out at me...

Source: https://flic.kr/p/8tvEvs

This small locomotive was originally designed for export to Ghana although a handful did operate in the UK. It's a tiny locomotive with a distinctive appearance, and I found a few photos of the example used by Severn Trent water, now preserved at Apedale, but previously at Cadeby - infact, it appears it may well have hauled the last train at Cadeby...

Source: https://commons.wikimedia.org/wiki/File:Last1_3.JPG

So I re-scaled the drawing, and drew up some parts in 2D to have laser cut. The chassis is two piece, inner and outer, both cut in 3mm acrylic. The design will be used in the HH, so it was a test bed for ideas. A small 6V micro motor and gearbox are held in the chassis and drive the front axle via a Delrin chain. The wheel sets are connected by another Delrin chain. This approach seems to work well, although I need to ensure the distance between the wheels lends itself to a particular length of chain as this prototype is a little tight.

The model uses a 2mm styrene body, cut in various parts and glued together. Inside the bonnet a small Strikalite 4xAAA battery pack is contained along with a Micron RC receiver, switch and charging socket. I have started to add details using laminations of thinner styrene, MENG and Cambrian bolts and rivets, and various profiles of Microstrip. The window seals are 2mm styrene that was laser cut and then rounded on the edges with a file.

The cab is tiny so will need a figure somewhat modified to fit in, although I've had some help from Si Harris about that, so I feel more confident in what I need to do... the bonnet doors will be etched, the artwork for these is complete, and I have drawn up in 3D the couplings, axle boxes and sandboxes to be printed by Shapeways.

The model isn't perfect and I've learnt a few things, but the increase in speed when assembling the basic model mean I can adapt this process for future models and it makes a small batch of a prototype eminently do-able.

On that note, I should mention that the batch of Hudson Hunslets, scheduled for early 2019 are now all reserved - thanks everyone!

More on the Motor Rail soon...