Friday, 14 September 2012

A Removable Crossover Module

One of the greatest difficulties I have found in running a 00 garden railway is keeping the track clean enough for good electrical continuity, and the worst problems are in the turnouts (points). I have therefore designed my latest group of turnouts, in the form of a crossover, as an easily-removable module which can be kept safely indoors when not in use.

The crossover temporarily in place, before it became a removable module.
The removable crossover has been tested in situ, and works well. It's currently electrofrog, wired for DC with the feed from the bottom right track and both frogs switched by the blade. However, all connections are brought to the edge of the PCB, so a change to external frog switching or DCC should be relatively easy, and is currently in progress.

I'll give it a bit more use before I waterproof the circuit board with several layers of suitable varnish, and apply the ballast. The single track from the tunnel comes in from bottom right, and reverts to double track. The spur at top right will be a freight-only branch to the top corner of the garden, and will require a severe gradient, probably about 1 in 15.

The removable bit is everything on the rubberised cork base with the veroboard inlays. The veroboard is connected to the rails by short wires soldered unobtrusively to rails, or the Peco-fitted wires where available. The red lines on the veroboard indicate the position of the used conductors on the underside.

The crossover during construction. (Image inverted compared with others on this page.)
The crossover in its initial working state, manually operated.

The assembly seems to be rigid enough for careful handling, though I normally keep it on an offcut of board when not in use. When fitted, it sits on a flat base which would normally be the base for the 3mm foam underlay. The rubberised cork is 3mm thick and the veroboard 1.6mm + solder joint. A larger assembly would become difficult to handle, but this one is fine.
It is currently connected to the tracks either side by sliding rail joiners. I use Gaugemaster, as they have a notch each side at one end, ideal for gripping with fingernails or fine-nosed pliers. This system has worked fine for a year for the viaduct. The intention long-term is to provide a connector or terminal block to the power and control bus wires.

1 comment:

  1. Great idea Ian, I follow your progress and updates on the OOGardenrailway site. It will be interesting to see this idea developed further.