Track panel construction using jigs

I was planning to lay around 150 metres of track and wanted this to be as maintanance free as possible so I decided to use Maxitrak aluminium rail and sleepered Jubilee track. The rail is supplied in 2.5 metre lengths with 17 sleepers per length. To speed up construction, I decided to make up standard 2.5 metre straight and 6.37 metre outer rail radius curved panels. 6.37 metres was chosen since this meant each 2.5 metre outer rail length formed a curve of exactly 22.5° with 16 making up a circle. This is how to make the panels.
Use my Excel spreadsheet to calculate the exact position of all the sleepers using straight and curved jigs of 25mm by 50mm timber. To construct a straight jig fix 17 pieces of 24.2cm long (sleeper length) timber between 2 pieces of 250cm long timber at centres shown on the spreadsheet (i.e. 7.35cm, 22.06cm etc) from one end to form a ladder type construction. The curved jig needs a little more effort. Put 2 pieces of 60cm by 125cm chipboard short ends together. Using the spreadsheet decide what radius curve you want. Then use the x and y figures to plot out the inner and outer positions of the centre of each sleeper, with x=0cm being the board join. Using the 6.37m example, put a mark at (x,y)=(0.00cm,2.50cm) and (0.00cm,26.70cm) on one board for the middle sleeper, then (14.83cm,2.67cm) and (14.27cm,26.86cm) for the next and so on. Do the mirror image for the other board. Glue 24.2cm long pieces of timber between all the centres, with small holding pieces at each end of these. Hopefully the picture will make it all clear!
The inner rails of the curves should be cut with a mitre saw by the amount calculated in the spreadsheet. The straights and the outer rails of the curves are all the full uncut 2.5 metre length.
Draw a 1mm thick line across the middle of one of the fishplates. By placing the fishplate with the edge of the line against the rail end this produces a 1mm gap between the rails to allow for expansion. The centres of the two fixing holes are marked in the rails, and a small hand drill with a 1mm bit is used to provide a drilling guide. The fixing holes should be drilled out to a 5mm diameter. The fishplate screws have a 3.5mm diameter, so this together with the 1mm rail gap allows plenty of margin for expansion. This is particularly necessary with aluminium rail as is has a high thermal expansion coefficient.
Now bend the curves to the desired radius. If the curve is not too small, this can be done successfully in a Workmate bench, but it is much better to use a rail bender. This is simply 2 fixed wheels with a width to fit along the rail upright, and a third mounted on a threaded bolt beween them. The rail is run to and fro with the movable wheel gradually being screwed in to form the curve.
Place the sleepers onto the jig and then the rails on top. It can help to open out the aluminium tags a little first. Align the rails so they are central with an equal overhang each end. Use an adjustable wrench to squeeze all the tags onto the rails. Then bang the tags down using a short piece of 12.5mm square steel rod hit with a heavy hammer. Two or three blows should be enough. It can help to slide a thin piece of 25mm wide steel bar under each sleeper in turn so that the tags are not pushed into the wood when hit hard. Ear defenders and eye protection are essential.
Repeat the process for as many panels as you need. I found that it took me a morning to make around 5 panels from scratch. Using the jigs means that you get accurate curves and evenly spaced sleepers which makes running all the smoother.