Modelling the Old Olney (Midland) Station in '00' Gauge
The Full Story Of Its Construction (2)
Table and Track Bed Construction
The photographs below show baseboard and track construction under way. A number of baseboards were constructed, using 2 inches x 1 inch planed timber and good quality plywood for the track base.
Progress Review (February 2014)
The club held a review of project progress in early February 2014 and mapped out the way forward.
A decision was taken that Peco code 75 track and electro-frog points would be used instead of the fine scale originally planned. The table / board end joining system was modified from the original plan, using metal pattern makers dowels, with the new end boards drilled using a pillar drill to achieve greater accuracy. Work progressed on laying out the track ready for the construction of the raised landscape area.
An extension frame was found to be necessary and constructed to stop the points from straddling two tables. The type of point motor had been discussed, with the SEEP solenoid type being preferred, mainly because the club had twenty or so of these in stock, and also because Don had already made a printed circuit board (pcb) to facilitate mounting these. The pcb had two micro switches on the assembly to change polarity of the point electro-frogs and also to switch Light Emitting Diodeson a mimic panel, to indicate the point setting position.
The pcb, micro switches and motor had been used on the St Peter's Yard layout, built in 2013 to explore DCC techniques. Don also demonstrated an alternative device to operate the points, using the MERG (Model Electronic Railway Group) CBUS control system, comprising a pcb to mount the servo and two microswitches, similar to his SEEP board. It was however, agreed to proceed with the SEEP motors until stocks ran out.
The views above show the use of the pattern makers dowels, and the use of copper strengthening pieces used to take the tracks over table joins to facilitate disembly and re-assemby of the layout once it was complete. The right hand side copper strengthener has not yet been cut. Once in position, cutting was done with a saw Temporary spacers were put between the boards during the cutting operation to maintain the required gap, once the rails have been soldered to the copper. A groove is cut along the length of the copper (parallel to the tracks) to provide electrical isolation between the tracks before it is screwed down, making sure the screws do not bridge the gap.
All the track sections had dropper wires soldered to the bottom of the rails. There are two circuits, on the left red and black and on the right blue and orange. The yellow wires are connected to the point frogs or dividing centre. The support pieces for the high level board can also be seen above.
The DCC system chosen to power the track was the NCE system, using a 5 ampere power box and two hand held controllers. This was chosen because the system is flexible, allowing for further controllers and power boxes to be added easily should the layout be expanded (and as money became available!).
The original decision to use extensive wiring for points control was changed in favour of using the Model Electronic Railway Group (MERG) CBUS system to control them and relay their position to the Mimic/Control Panel modules, as reducing the number of wires needed to go between the boards to control the points and indicate their status would reduce the complexity of cabling everything on installation, and make things more straightforward to fault-find should a problem arise.
A number of points were installed using 'SEEP' solenoid motors to switch them whilst others - particularly double-slips and 3-way points - use servo motors with an associated relay to change frog polarities as the reduced 'travel' on these points was insufficient to reliably operate the built-in switch (to change frog polarity) had 'SEEP' motors be installed on them.