Work continues to progress at a steady rate, the last couple of weeks
seeing the extension of the yard at what is now known as “Anbeon” completed. The
extension of the yard trackwork on this corner module (highlighted in green) consists
of a single set of points with about 450mm of track either side, so nothing
overly complicated.
This corner module already contained the curved track and first set of
points for Gunnedah’s main yard, so it
was only a matter of adding the extra track and set of points, and then
flipping the module over and joining the new dropper wires to the existing bus
wiring.
All of the points on the upper
deck level of the layout are equipped with Cobalt IP Analogue point motors,
made by DCC Concepts, and the point motors are controlled by Alpha Switch A
boards, also made by DCC Concepts. Each board has six outputs, and each output
has the capacity to control two point motors, so you can control six individual
points or up to six pairs of points.
Driving tw0 point motors simultaneous with the press of one button is
handy where you have two sets of points forming a crossover, where you will
always change both points at the same time. The buttons used with the boards
are a very small and neat pushbutton design equipped with an LED, with two
buttons controlling a single set of points, or three buttons when you have two
sets of points forming a crossover. So making a control panel with the track
diagram, the buttons are placed on the diverging side of the points, so when
selected the appropriate LED lights up indicating route selection. This is a
very effective system that is very simple to set up as it is literally a plug
and play system.
Whilst there doesn’t seem to be a limitation within reason of how far
away the points can be from the control board (I have tested to a distance of
about three metres), as I am using a modular style of construction, there are a
couple of places on the layout where the control panel and control board will
be mounted on one module, and one or more sets of points operated from this
panel are located on an adjoining module. Because of this the wiring between
the control board and point motor cannot be continuous, so a method of easily
disconnecting the wiring between modules needed to be found.
After doing a fair bit of looking around it appeared that a suitable
style of plug would be a four pin style that is commonly used to power the
small cooling fans inside your typical PC. Looking on eBay, I found that you
can buy twenty centimetre leads with a female and male plug on opposite ends,
with fifteen of these costing nine dollars $9.00 including delivery.
With each point motor controlled by only two wires, each plug can
therefore handle joining two sets of points on an adjoining module. Using them
is very simple, we simply cut each lead in half, strip the insulation off the
end of each wire, strip the insulation from the wires coming from the control
board, twist the wires together, add a dab of solder and then slide some heat
shrink over each joint. The point wiring is then permanently attached on the
underside of each module, with the male and female plug sticking out about five
centimetres from the corners of the adjoining modules. This is enough so the
plugs can be easily plugged and unplugged, and once plugged together can be
tucked back under the modules.
When the point control panels are made with the point motor boards
attached to them, I also want them to be easily disconnected from each module,
so there needs to be a plug to disconnect the boards from the three wire power
bus that runs around the layout framework specifically for the point control
boards, and another plug to disconnect them from the wires going to each point
motor.
The control boards have screw terminals for the main power (three wires)
and point activation wires (twelve wires), but the idea of unscrewing up to fifteen
wires to remove the boards is crazy, so again I spent time looking for
appropriate plugs.
For the three wire main power plug, I ended up using the same style of
plug used on remote control servos, and again these can be bought as short
extension leads with a male and female plug on each end, and if you are willing
to wait a couple of weeks for delivery, they can be bought as cheaply as $2.99 for
ten leads including delivery!
Once again these leads are simply cut in half, one half is soldered to
the main bus wiring running around the room, the other end attached to the
three screw terminals on the control board. This provides another neat and tidy
connection that is very easy to unplug when needed.
That then leaves the actual point control wires that need to be able to
be disconnected when the control panels are removed, with up to twelve wires
needing to be disconnected this time. After looking around I came across what
seemed to be commonly referred to as D-Sub connectors, which are available in a
few different styles, but the ones I chose have screw terminals for fifteen
wires, and a male or female fifteen pin plug (DB15).
These are a more expensive style of plug costing around $9.00 each
(eighteen dollars $18 for a male and female set), but they are well suited to
my needs. The wiring from the control board is run to one plug with all wiring
being colour-coded for identification and tagged where necessary, and the other
plug is located on the appropriate module with the wires from each screw
terminal going to the appropriate point of motor/motors.
As these plugs are bigger and heavier, and sit on the underside of the
modules, I wanted a way of securing them to the underside of the module, but
still make them easy to access and to pull forward so they can easily be
plugged and unplugged. After deciding that most styles of clips or hooks would
be too cumbersome, I hit on the idea of using magnets.
I had purchased ten Neodymium block magnets (19mm x 10mm x 1.5mm) some
time ago, primarily to experiment using them as uncoupling magnets, but figured
if one was glued to the underside of each plug, and then in the appropriate
position on the underside of each module, four magnetic flathead screws are screwed
into the foam module, the plug is quite firmly held in place, and yet can be
easily slid forward to be plugged and unplugged, and then pushed back where the
magnet once again firmly attaches the plug to the screws.
I find that it is definitely worth thinking outside the square, and
looking to other hobbies and forms of technology to find solutions to our model
railway problems.
Cheers
Darren
