How I constructed a Ruston Proctor paraffin locomotive

 

Having constructed a fairly ordinary Ruston diesel (see How I constructed a Ruston(ish) diesel locomotive), during my researches about it, I was very much attracted to the very early Ruston Proctor paraffin locomotives and felt a strong desire to construct one.

As with the Ruston, I was unable to track down any scale drawings (which has since been remedied - manyfold!) and so had to base my construction on photos. However, my internet searches yielded a downloadable 3D printing file for a Ruston Proctor loco in Gn15 scale on the Shapeways website. At around £16GBP, this seemed like reasonable value, and so I delved deeply into my pockets (well my PayPal account) and purchased it.

 Unlike my own 3D drawings, where I break down a model into separate components which can be printed flat on the print-bed, this download comprised a single .STL file of the whole locomotive. This was completely unknown territory for me, and so I wasn't quite sure how to proceed.

The file was too large and complicated to import into TinkerCAD, so I was unable to break it down into sections. I loaded it into Photon Workshop, the slicer for my AnyCubic Photon resin printer to check its dimensions. As I wanted it to run on 45mm gauge track, I decided it needed to be enlarged - although Gn15 locos are supposedly G Scale (c1:20), they are designed to run on 16.5mm gauge track and so (as in this case) it would probably be a bit too narrow.

At around 46mm wide, I felt it was a bit too narrow for 45mm gauge. I'd not seen images of the inside framed three foot gauge Ruston Proctors at this stage and assumed it would be outside framed. And so, .......

...... I decided to enlarge it sufficiently to fit over one of my bespoke 3D printed powered chassis (see How I designed, drew and 3D printed my own powered chassis - pending). 

 

 I widened the model to 65mm and increased its overall proportions to match.

 I recognised that this would now no longer make it a scale model of the original, but felt it is in keeping with the design. All my models are based loosely on their originals, and so exercise the rubber ruler principle. Besides, making it larger would allow me to fit the batteries, radio control, soundcard etc.

Once it had finished printing, I needed to do a fair bit of tidying to remove all sign of the supports. I was then faced with the problem of modifying the body shell to fit the chassis.

I felt justified as, once I did track down some images of the loco, quite a few compromises had been made to enable it to fit its 00 powered chassis. The Shapeways version did not, for example, continue the curved cab sides across the inside of the cab which is quite a predominant feature of the original loco - and also provides a great way to hide the mechanism.

The missing parts were drawn in TinkerCAD and printed out.

...... as were new side frames.

The body was then reassembled and given a couple of coats of Halford's rattle can filler primer.

The electrics were wired-up using my tried and tested circuitry and a Deltang compatible Micron MR603 receiver controller and a cheap diesel engine soundcard from AliExpress.

Click to enlarge

Incidentally, the soundcard needed a servo signal input - so the MR603 was reprogrammed to provide this on Pad 3. See How I use cheap diesel soundcards with Micron MR603 receivers - pending

Once it had been successfully test-run strips of lead flashing were crammed into every available nook and cranny and the loco was taken through the paint-shop and given the default PLR livery of Rover Brooklands Green from a Halford's rattle can aerosol.

 It has been assigned the number 26 and given the name, Greg, after my garden railway modelling friend who lives in Sydney.

 With the addition of buffers, couplings, a driver and some controls in the cab, it has now entered service.

 I've not yet decided how it will be deployed, but for now I reckon it will often be found pottering around the sidings at the sand quarry, with occasional forays into Bickerton Station.