I'm a bit "out of it" from low blood sugar and can't recall if I mentioned it or not; deep reading a real chore at the moment; but leaving a way for track to expand a little is prudent. The rails do get warm and expand some when in use. Too tight and buckling pressure can occur.
A volt/ohm meter may help a lot. Harbor Freight often has coupons for a free one with any purchase. Finding another useful item is pretty easy. It's not professional quality,(few items there are), but good enough for the majority of work we do in the hobby. Better than a caboose ...at times 
