Live steam model on 7¼" gauge of the Württembergische T3 no 924

Welcome to this blog. It will inform you about the progress of designing and building miniature live steam, coal fired locomotives for passenger hauling. Currently I'm working on a 7¼" gauge, scale 1:8, German T3 steam locomotive.

In 2006 I started this new project. This is a small 0-6-0 branch line locomotive of German (Königlich Württembergischen Staatseisenbahnen) origin with outside cylinders and Walschaerts valve gear. The loco is about 1.10 metre long and will weigh approx. 100 kg.

On the left you'll find the index where you can browse through the different articles and on the right you'll find all the extra's. On the top tabs you'll find a brief description of my other locos.

Enjoy this site. Erik-Jan Stroetinga. The Netherlands. Europe.

Friday, 22 February 2013

Starting the boiler fittings

 The handwheel in Solidworks according to the german standard. 

Turning from a solid brass rod the contours of the handwheels. Outer diameter, 22.5 mm.

With several lathe tools the handweel gets its shape. 

The CNC program is for the spokes is loaded and ready for milling with a 3mm end mill.

The controller software USB-CNC is running on an old laptop. 

 The progress of the milling cyclus (the cutter wasn't too sharp)

 Before and after the CNC milling operation which took about 20 minutes. 

After finishing with the lathe the first batch of wheels. The square hole is yet to be punched.

A week of CNC.

Boiler fittings in progress.

Sunday, 17 February 2013

CNC needed for numberplates

Loco number plates for the T3 are not available in the model engineering trade.  I had a sample of a real shed sign, which was the base for my loco plates.

The design was done in Solidworks. 

To make these, I had to buy and convert a milling machine to CNC. A model engineer gave a tip to look at http://www.impulsecnc.nl. This supplier gave me good advice in how to build a home-made CNC milling machine and which components were needed. I started out with the basics: power supply, drives, USB-CNC controller and stepper motors. A cabinet was bought second-hand.

 The wiring-up was done according plans. Simply follow the given instructions and connect all the pins of the controller board to the drives and power supplies.

A setup had to be made to connect the motors to the spindles. These are stepper motors of 4.5Nm connected to ball screw spindles with an pitch of 5mm.

Setting up the USB-CNC controller required some jumper settings. On the drives the dip switches had to be set to a given motor Amp and micro step.

First test in milling with the new machine in PVC. 

The complete set-up of the Wabeco F1210 as a CNC milling machine.

The steam turret on top of the boiler, also done with the aid of the new milling machine

The number plates on the cab,

Wednesday, 13 February 2013

The Solidworks drawing

I started out with Inventor software for the 3D modelling of the loco. At my work at Fontys University of applied sciences, I have made to change to Solidworks because we got better support with this software. To get familiar with the 3D modelling CAD software, a 3 day starter course isn’t enough; so I had to get some hand-on experience myself.



What better way than to make your own drawings. Designing the locomotive in 3D is great to do. You’ll get an instant view and ‘feel’ of how things will look on the loco. In the assembly drawings, all the parts can be fitted and checked on the virtual locomotive.


Even the total weight of the loco can easily be determined. The valve gear can completely be tested in forehand; so when I start to cut metal in the workshop, I know the parts will fit. From every 3D modelled part a 2D workshop drawing can be made very quickly. A change in the 3D part will be automatically up-dated in the 2D drawing.

February 2014

The first concept drawing of the driving wagon. Based on an so called Omk open goods wagon of the German railways. The drawing is based on measurements I took off a gauge 1 Märkin wagon. This is a model a typical European open wagon with a 4 meter wheel base, 6.7m long loading floor with a 15 ton loading capacity. 

March  2015

May 2014

May 2017, render in Solidworks; final livery

Loco with the open wagon (for the driver to sit on)  and beer wagon. 

The Solidworks drawing can now be downloaded at GrabCad  or directly from our model engineering society site www.stoomgroepzuid.nl

Possible a next project?  A quick sketch of  a Stroudley Terrier in comparison with the T3.
The T3 is a small loco in 7¼"; the Terrier is even smaller. However much of the boiler parts are identical,  the driving wheels (158 mm) even bigger and  a longer wheelbase. (470 mm)
Nice loco; see here

Sunday, 10 February 2013

The smokebox

The smokebox
This is a classical design, with the flared out front plate. The Stroudley A1 Terrier locomotive has the same kind of smokebox shape.  That loco was from the same period (1880’s).

 I used a piece of steel pipe (160mm diameter) on which the front plate is silver soldered. 
The door is a combination of a steel turned disk and a curved steel plate, also silver soldered on. I’ve used the standard dart design for closing the door, because I couldn’t figure out how this worked on the original Württ. T3.

The base of the chimney is formed by fly cutting with a boringhead. This is set to the radius of the smokebox.

After leaving the milling machine, the outer shape was turned in the lathe.

Although a extreme long overhang from the chuck, boring out the chimney was done in this set-up. Easy does it! :-)

In three steps the inner conical shape was turned.

The rotating center in the tail stock is inside the chimney, when the out side was turned. For both operations (in and outside) the cross slide was set to an angle of a few degrees.

Drilling holes for mounting the smokebox on the frame

The smokebox saddle consists of two strips of mild steel

Finishing the hinge by hand

The hinge is made from a steel bar, that was first reduced to thickness of 2 mm in the shaping machine. You’ll see in the photo the 8mm square lumps, that became the eye of the hinge. This job has been done by filing.  

The complete assembly.