On Sat, 08 Dec 2012 09:26:49 -0800, Oren wrote:

I have seen plenty installed by professionals and watched
them intently. Following the threads here, I learned some things.

I forgot to mention that I also learned that the torsion bar is
NOT supposed to move sideways when the door opens and closes
(allowing for the tiny bit of unavoidable slop at each side's
cable-drum-to-end-bearing interface).

What Dan Musick told me by phone was the only sideways 'movement'
is in the spacing between the coils. This wasn't intuitive to me
because I personally twisted that spring 7 times and watched it
grow almost two inches in the process (i.e., 7 quarter-inch coils).

I kept wondering where that two inches went when the spring
untwisted on the way down! It turns out that two inches is hidden
between the coils!

It's intuitive once you know it - but not until you do it!