Today, I decided how, and did it. I used thumbtacks to attach the 1:1 sheet to the plywood. I then placed every turnout on the layout, and partially nailed them down. I also built the connecting pieces for the switches which are really close together, and placed (and lightly nailed) every other piece of non-curve track. The curves will be flex track, and will involve some nudging, so I didn't bother trying to fix their positions just yet. Here's everything lightly-nailed:
Then I removed everything, annotated the holes so I know where to pick up next time, and labeled all the pieces.
One little snag I hit. My shiny new Xcelite 170M shear cutters ... well ... sheared:
I tried to soldier on with the cutting of custom-sized connecting pieces from Flex Track without the shear cutters, but the quality of the cuts suffered pretty dramatically as a result. Right tool for the job and all that -- this is pretty clearly a necessary tool.
Before laying the track, I tested each turnout. I first tried hooking the turnouts up to the rail outputs of my DCS50 DCC controller. I figured that DCC looks an awful lot like AC, so maybe it'd work. It made the turnout solenoid vibrate, but not much else. A Google search revealed a number of turnout guides which mention using the AC Accessory outputs on the controller to power the turnouts. Alas, I have no such output. It looks like I need a separate power supply for the turnouts. Whether that's a straight DC power supply with individual switches or something fancy like a Digitrax DCS64 (to allow DCC switch control), I have yet to decide.
Back to turnout testing. When I realized that I couldn't use the DCS50, I hooked the turnouts up to my bench DC power supply. At 15V (and a power-supply-imposed max of 1A), most turnouts switched properly, if a bit hesitantly. A couple of them got stuck. Turning it up to 20V fixed that problems. I don't know if this is an artifact of my use of the bench power supply or something more. Will I need something like this capacitive discharge controller?
I had intended to move straight from this initial placement step to the laying of roadbed and track, but now I realize that I need to think more about how the wiring will work. If this layout were on a table, that'd be easy -- I could drill holes, and route the wires under the table. As my wires will share the same side of the plywood with the track, I need to figure it out now. So much to do.