A quick update on the roundhouse since it's been almost 9 months since I posted any progress on it. I took Norms suggestion and got a dedicated power supply at 12 volts, bought 750 ohm resistors, and placed everything under the roundhouse. So each LED has its own load resistor. I did the buss bar thingy using 14 ga copper wire and gluing that to the bottom of the roundhouse floor.
I glued all the panels in place finally. So it's now complete, structrally. Now, it's getting the layout built and placing the round house in it's position. Pictures will follow at a later time, due to logistical issues.
Until next time...
