Leon Fisk wrote:
On Wed, 21 Sep 2011 13:20:55 -0700
wrote:

snip
OTOH, Constrained against Bubba's mass x coefficient of
friction at the bottom and the Joist near the bottom
of the top section, my Mass is only distributed among:


1) About 2 sq. inches of 0.063" thick aluminum at the
bottom of the top section bearing against about
2 sq. inches of 0.063" thick aluminum near the
top of the bottom section.

2) The latches at the top of the bottom section

After I sent my "idea" it occurred to me you might have a wood
extension ladder which wouldn't work very well for what I had in mind.
I was thinking of the type 1A or 1 fiberglass or aluminum models that
use an interlocking track the full length. Like this:

http://www.wernerladder.com/catalog/...?series_id=139

You still should be able to make this work though, unless you can
borrow a better suited model from a neighbor, relative...

The pity is that I have a nice ag ladder that would work really well.
It won't fit in the garage, though.

Do what I said before (lash to joist and vehicle at bottom) then extend
the top fly section to desired position. Then take some rope and tie
the two sections together at the bottom of the top section. Keep tying
until you feel comfortable that the two sections aren't going
anywhere...

That lever arm still bugs me greatly.
My ~300 lbs. dangling in space is gonna put some real torque
on whatever tiny overlap there is, in a direction the ladder
was never designed to handle. Short of full-length welds
to hold the sections together, I don't see a way to keep the
ladder in one piece through the operation.

I'm pretty fit yet for a late middle age old fart, so doing things
like that doesn't bother me a great deal. Of course I know people who
wouldn't dream of trying anything like that, even when they were young
and supple ;-)

Wayell, I was never fit, even as a young'un.
I've been on the roof several times using my agricultural ladder
to do my fan installation and that doesn't bother me at all.

I suspect that the quickest, safest, cheapest answer is just to jump
back on the roof, remove the weather cap, impeller, motor and support
frame on my fan and just tidy up the round opening underneath using
some sanding cylinders. Reassemble everything and Bob's My Uncle.

Thanks for your thoughts on this Leon.
I appreciate it.

--Winston