3D Printed QR DH Class Locomotive

 A reasonable way to get a S Scale QR locomotive is to start with a model of the DH class, as every layout needs a DH shunting locomotive!

Many more photos of the DH Locomotives and other QR rolling stock can be found on the Wuiske Models web site, http://www.wuiskemodels.com/. Check out the Prototype Photos section. They even have some S Scale kits for sale.

Black Diamond Models used to produce a fine ready to run DH model in S scale, but I have never seen one of these come up for sale on the second hand market. If you are lucky you may be able to get Black Diamond Models to produce a unit for you, but be prepared for a long wait as he is very busy with the HOn3.5 RTR line of models.

Other options are to built one from scratch with Evergreen plastic sheet or you can get a 3D printed model from Shapeways, at https://www.shapeways.com/model/748079/qr-dh-s-1-64-scale.html?li=search-results&materialId=60.

I have gone for the Shapeways solution. The body is designed by Gvrocksnow, who originally produced the model in HO, as the Puffing Billy version and was kind enough to scale it up to S Scale and add the buffers. It is available in Strong & Flexible Plastic or Frosted Detail, so pick the one that fits your budget.

I have both the Strong & Flexible Plastic and Frosted Detail versions. The Frosted Detail version naturally has better fine detail especially around the grills and door hinges.  At the end of the day both look very good and will be hard to see the difference between the Strong & Flexible Plastic  and Frosted Detail versions at a arms length.

The following is a high level description of how to make a mechanism for the Gvrocksnow Shapeways DH body:-

For a mechanism, I have gone for a quick solution using an old Athearn Blue Box 4 axle diesel switcher, SW1500 or SW7 etc.The wheelbase of the bogies are still a bit short, but behind some shortened side frames they should look okay.

The Athearn mechanism needs to be lengthened by 4mm and the wheels replaced with North Yard 480N wheels for the correct diameter.


The North Yard 480N wheels are 42 inches in  S scale  (14.3mm diameter), and you will need 8 of these. The web site for North Yard is http://northyard.co.nz/.

Use a course metal file to reduce down the sides of the fuel tank on the Athearn switcher chassis.

Test fitting the Athearn frame.

4 x 1.4mm x 10mm self tapping screws have been used to fix the body to the chassis.

You may need to place shims under the frame so the body sits at correct height. (0.5mm under bogie pivots and 0.75mm on locomotive frame)

North Yard wheels 

 Move front flywheel, motor brush end, forward on shaft by about 3mm.

Some of the interior detail need to be removed to make room for the Athearn fly wheel.

Need to add a driver

The Athearn motor is very loud, so if you want a very quiet running model try replacing this with a Mashima motor, a 1824 should fit. The Athearn gear towers are very quiet when lubricated properly. 

Run wires direct from the bogies to the motor or DCC chip. Do not use the original Athearn power pick up from the bogies to the motor as it will only give you trouble.

Ready for adding hand rails and shortened side frames, then off to the paint shop

The Shapeways printed bodies need to be washed in soapy water to remove the wax coating from the printing process. The surface is still a little course so check the web as there is a lot of good advise on how to get the best paint job on these models.

The Australasian Model Railway Magazine produce plans and a small story titled "Walker's Diesel Hydraulics" in Issue 83 March/April 1977. This is available in PDF format on CD through their web site, https://4tknox.au.com/australianmodelrailways.com/evbooks.html.