Two layers of 1/4inch plywood, overlapping halfway, glued and screwed together, carry the track. Together this makes for a solid 1/2inch plywood support, which flows smoothly even when the slope is changed. 1x2inch laths support this plywood base, at least every 20-inch. This way there is no bending, even when heavy engines ride over.
Next the track center is drawn: distance between tracks 2 inches, 3/2inch from any surrounding obstacles. With curved track, these distances are increased, following NMRA-standards. A handy aid when drawing curves is by using a thin flexible steel rod, held in place by pliers. This way any curve can be drawn, including transition curves. Using a felt-tip pen, the centre lines are drawn on the plywood sub roadbed.
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On top of the plywood, using contact cement instead of carpenters glue this time, a cork sub roadbed is glued. It consists of two layers of one-inch wide, 2mm thick cork strips. Each strip, cut from a roll of cork I bought at a home improvement store, is glued at a side of the felt-tip-drawn line, thus keeping the centre of the track "visible".
I use two layers of cork on top of each other to get the required 1/6inch thickness. Using 2mm thick strips allows for easier following of curves, and gets a smoother top layer for the track (no bumps).
| ©2003 Gerolf Peeters - updated 07.11.2005 | See: Frame - Helixes |