Rowandale was started in 2012, but due to a pending house move little progress was made till late 2014. After the move, and once priority renovation was completed on the new house, work resumed on the Rowandale layout.The first section, shown at right, is how it was prior to our house move; track all laid with a tunnel entrance under a hill at bottom left and short viaduct just before it.
The short viaduct and tunnel have been scratch built in card using photo realistic texture sheets from the Scalescenes range.A mock-up of the station is in place and a start has been made on the scenery. Miniature model aircraft servo motors (Type SG-90) have been added to operate the points; the servos being mounted just in front of the rear storage tracks and are connected to the points by the wire-in-tube method. The servos are controlled by thePololu Maestro Servo Controller, the large bundle of wires to the servo’s can be seen here.The polarity of the frogs on the points are set with micro-switches operated by the servo motor arms.
The station approach road and bridge has been added, together with the station yard, small goods store and groundwork in the goods yard, including fencing. An engine shed, water tower and turntable have also been built. The station building & large factory at the rear are is still in mock-up form.Retaining walls, with storage units and a couple of shops under the arches, have been added at the rear of the goods yard, with road access via a ramp. A coal merchants office is also here. There is again a mock-up of a factory unit with chimney.Above the retaining wall, at the level of the main town, some buildings are completed, whilst others are under construction, or in mock-up form. The front half of this raised section covers the servo
motors, which operate the points. The rear half covers the hidden holding tracks. Both parts will be removable in case access is needed to the tracks & servos underneath. As well as completing the buildings in this raised area, the roads and garden & grass areas need to be constructed, and the buildings set into it.Some of the buildings were originally on the rear of Archie’s Yard, which was originally intended to be a quick lash-up, but did become a full layout.Temporary semicircular tracks, on a ‘D’ shaped board, have been added at the right hand end to allow continuous running on the main line and give access to the goods yard.
The Route Selection push buttons on the original front panel were connected to a serial chain of resistors, which sent an analogue signal to the Pololu Servo Controller. This was then interpreted as a Route Number, and the corresponding servos operated to set the required points. Because of occasional electrical noise problems on the analogue signal it was decided to change over to using digital commands instead.
Initially an old industrial micro-controller was used, as I had one left over from my working days. However this was gross over-kill for the task, and would be expensive to replace if it ever failed in the future. Next a cheap PIC Micro-controller was used, but was rather slow and the software did not easily lend itself to multi-tasking, which made the software development more complicated than it should be.A Raspberry-Pi 3B was next tried, with great success.
The Raspberry-Pi is an amazing little computer, designed and built in the UK, which uses an ARM processor ( as used in many mobile phones). It has HDMI output to a monitor, four USB ports, built in interfaces for wired networking, WiFi and Bluetooth; costing just £30. Onboard, it has 26 general purpose digital Input/Outputs (GPIO), together with an I2C data bus through which a very large number of remote digital I/O can be controlled. It uses a micro SD card for storing the Operating System and program code.The usual operating system for the Raspberry-Pi is the Raspian installation of Linux, together with the Python high level language, which supports program threads running in parallel, this proved an ideal choice, for the new control panel.The control of the speed of the locos is still using the free open-source software JMRI DeCoder-Pro, but instead of running on a laptop, it now runs on a second Raspberry-Pi 3B. It was possible to run both the Route Setting procedures and the DeCoder-Pro software on the same R-Pi 3B, but despite the 4 core processor, sometimes the speed of response to commands exhibited a slight delay.
The Raspberry Pi Organisation have recently developed a minimal version, the Raspberry Pi-Zero; see photo at right.This model has only one processing core, the minimum of interfaces, & is slower, but costs just £4. It has the same digital I/O interfaces as the bigger model and is proving very popular for small control tasks. On Rowandale one is now used to drive a stepper motor to operate the turntable. Programmed with the sequences for energising the stepper motor coils ( via a driver interface ), a single push on the control panel button, causes the stepper motor to turn the table exactly one half revolution; with acceleration & deceleration.
The large factory at far left, which covers the curved tracks leading to the hidden sidings, is now finished, together with it’s clock tower, associated low relief buildings behind it, and the entrance gateway. Internal fittings & people have been added.A low relief mill building has been added behind the garage, completing the range of buildings covering the hidden tracks. The industrial units have been set in their yard areas with surrounding walls and suitable bits & pieces, and workman positioned.
The back gardens have been added to the cottages, attached to the pub. The row of half relief cottages - which were used on Archie’s Yard are yet to be replaced.These buildings at the rear, which cover the hidden tracks, and in the middle distance, which hide the control units for the points and sensors, are built as removable modules to allow access to the tracks and the electronics.
The modules individually are shown in the gallery below.
See the page for detailed views of the buildings.
The final module over the servo motors is this row of eight full depth cottages, which have replaced the temporary half relief ones - which were used on Archie’s Yard. ( No. The pigeons do not fly! )
A start has been made on the scratch-built station and waiting shelter, the latter is finished and the bases for the main station walls cut-out.
Originally a Midland Size 2 station was planned, but it is now going to be the smaller Size 3; partly because window & barge board frets are available for this size, but not for the larger one. Also this is probably a better fit for the size of the town.