The base of the NDM is quite heavy – probably heavier than necessary. The foundation is a piece of 0.5-inch plywood. There are two nominal 2” x 3” (actual 1.5” x 2.5”) (“2x3”) pieces of lumber mounted to the plywood along their wide sides down the centre, leaving a 1” gap between them for a cable run. The cable run is not for the wiring of the NDM itself but for other wires that need to run to adjacent modules (such as the Loconet cable). At each end of the 2x3’s are several vertical 2x3’s mounted vertically to make a pocket into which are inserted the towers, braced by 3/8 inch plywood gussets.
The gap for the cable run is covered with an insert made of three pieces of ¼ inch Plexiglas formed into a flat-bottomed “U”. This prevents people transiting the NDM from stepping on any cables in the cable run, avoiding both damage to the cables and a tripping hazard.
There are two pieces of ½ inch sloping plywood which extend from each outer edge of the base to the 2x3’s running down the centre. Each of these leaves a void between the sloping plywood and the base. The wiring for the NDM runs inside one of these voids.
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| complete base showing pockets for vertical towers and Plexiglas cover for trough down centre |
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| closeup of end |
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| closeup of end, different angle; note the open hook to which the tower turnbuckle is inserted |
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| close up of other end |
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| the base with two vertical towers inserted and turnbuckles installed |
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the Plexiglas insert removed for illustration
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To be continued...
