Built By: Marcus Wong
Description: My build of the Y-Junction module design found at Layouts - an irregular pentagon shaped module that turns three standard corners into a reversing loop for the outer main, and a bonus mini loop for the inner main.
The short end of the pentagon is designed to have the standard 38mm T-Track fascia to front track measurement on both sides, so when you join that end onto a standard modules the "front" sides will all line up, but the back side will be deeper.
I chose 345 mm radius for the outer curves because I had them on hand already, along with some spare 29mm straight pieces. Note they don't quite add up to double track at the short end, but the track has enough flex to make it fit outside of CAD land.
Module benchwork is 40x18mm dressed pine for the three sides that mate with other modules, 70mm tall strips 3mm MDF for the outwards facing fascias, 30mm XPS foam for the deck, and legs are held into nut inserts driven into the pine at each of the five corners. The angle calculations are a complete mess!
Electrically the inner track is conventionally powered; but the two outer tracks have been divided into two isolated sections using insulated rail joiners, with independent track feeds provided. Hence five RCA sockets have been provided - inner main, left outer main 1, left outer main 2, right outer main 1, and right outer main 2.
To avoid having ugly RCA sockets visible on a front fascia, or being forced to use the module in a specific orientation, all five power conenctions are fly leads with a RCA socket on the end.