re: Rectangle Centre finder for all you non-squares.

I was initially concerned about the flex and altered the rod accordingly,

however, I didn't play with the swing in SketchUp

and only found it snafu'ed after assembly.  Should have been something like,

That centre brace handles any potential flex as just a tad too much pressure would break the lead before a flex.  Also keeping the brace in place is subject to extra downward pressure with the left hand.