The Test Track

Having arrived at an idea of how I wanted to build the various components I thought it best to construct a test track to try things out before committing them to full scale construction. This showed up a number of areas where modifications were needed or further thought was required in the design and construction.

The test track allowed me to experiment with the baseboard, laying the guide wire, junction and magnetic stop mechanisms and many other things. Not to mention to play with some motorised buses!

The Baseboard

The test track baseboard is built from foamcore board. This is a sheet of polystyrene foam sandwiched between two sheets of card. It is very light and surprisingly strong. You can buy it from craft and office supply shops or, if you are lucky, scrounge it secondhand from a supermarket or similar store. They use it for the big promotional signs that hang from the ceiling. Being light they do not cause such a problem if they fall down. Once the promotion is over the boards go into the skip.

The top surface of the baseboard is a 5mm thick sheet of board. The sides are made from two strips stuck together to form a recess for the top to sit inside. This gives a raised lip all the way around to catch errant vehicles before they leap onto the floor. Foamcore board can be stuck with Evostick Resin W Woodworking glue. The parts can be held in place with masking tape whilst it sets. To cut the board I used a Stanley knife and a long metal ruler on an A3 cutting mat. A lot easier and neater than sawing up bits of wood.

The Guide Wire

I had decided to lay the guide wire in a groove in the baseboard surface. I had initially intended to lay it on the surface and build the road up with a further layer of card but that idea seemed too difficult for a complex layout. To create the groove I made a special tool which was simply two craft knife blades glued either side of a plastic card spacer. This tool makes two parallel cuts in the card surface which can then be peeled off so that the guide wire can sit on top of the foam below. The trick is to cut through the card but not too deep into the foam. On the Mk.II tool I shall add a depth guide to stop the cut going too deep.

An oval was marked out on the baseboard using the bottom of a 12 inch cake tin as a template for the curves. The groove was cut out and the guide wire placed in it and then held in place with some wide clear tape. You could use ordinary Sellotape, I just happened to have a large stock of the wide stuff to hand.

Once the wire was stuck in place the first bus could navigate the circuit.

Bus Stopping

Once boredom had set in (after a few days) it was time to add a magnetic stop mechanism. I used a Bolton’s Bits electrical mechanism and wired it up to a SPDT c/off momentary contact switch and two AA batteries. The practical upshot is that the switch is normally in its centre position. Push it one way and the magnet moves to the Stop position. Let go of the switch and it returns to the centre. Push it the other way and the magnet moves to the Go position, again the switch returns to the centre.

Faller vehicles are built for the hobby on mainland Europe and so are left-hand drive. As a result the reed switches that are used for the magnetic stop are on the right-hand side of the vehicle which is their nearside. For UK models the reed switch needs to be moved to the left-hand side so that it is on the nearside of the vehicle. If it was on the right-hand side then it is possible that the magnet could stop vehicles travelling in the opposite direction. (See Top Tips for more on this topic.)

You Take The High Road...

The next step was to install a junction. Another in a long line of prototypes was prepared. The guide wire was lifted where the junction was to go and a circular hole cut through the baseboard using an Olfa Circular Cutter. The prototype mechanism was placed under the hole, the guide wires on its top were lined up with the ones on the baseboard and it was glued in place. The groove for the branching wire was cut, the wire laid and fixed in place and the mechanism connected up to a switch and tested. Once a few bugs had been ironed out a piece of tape was placed sticky side up over the rotating disk and then stick down with a larger piece of tape sticky side down. This ensured that the sticky tape didn’t glue the junction mechanism firmly in place. With a few modifications the prototype mechanism was ready to become a production version.

Complicate And Add Confusion

Buoyed up by the success so far further junctions and stops were installed. Once they were deemed to be working reliably after extensive playing (sorry, testing) the roadway was covered with clear plastic self-adhesive sheet, the type used to protect books. I had intended to use Fablon sticky back plastic of Blue Peter fame but was unable to locate any in the local DIY stores. The plastic was painted with Faller’s road coloured paint from the Basis Set to conceal the mess of guide wires, junctions and sundry markings below.

Now that this has been done the only way to know which route a vehicle will take is by remembering how you have set the controls. On a more complex layout some form of route indication would be desirable. As would an emergency stop facility!

Finally some pavements were added made from Superquick building papers stuck to balsa wood. These highlighted a fundamental difference between road vehicles and railways when it comes to planning clearances. On railways all the axles of a piece of rolling stock follow the same route and, as a consequence, the maximum overhang on a curve is constant. With road vehicles whilst the front axle follows the guide wire the rear axle will try to take the shortest route which leads to widely varying overhangs around bends. This needs to be taken into account when planning for pavements, passing stationary vehicles and traffic coming in the opposite direction.

Update: Having fulfilled its design function the test track was scrapped when construction commenced on Redhill and the various magnetic stops, junction mechanisms and switches salvaged for use on the new layout.