Track Tracer

I needed to accurately measure the edges for new platforms for our club model railway layout, so I updated my earlier design of track tracer:
The lower wooden block is grooved so that it accurately tracks the rail line; the pencil lead (with a weight on top to provide pressure) draws a line on the plasticard in order to cut it to match the track.

These are the platforms constructed using the tracer:
Each platform is around nine feet long and split over three boards. The platform edges are commercially available plastic mouldings.