On Sun, 18 Dec 2005 10:51:27 -0600, "DanG" wrote:

I would point out that I just loaded on my trailer two pieces of
2x2x1/4 wall twenty foot sticks that had been unloaded with a
single choker at mid point. They both have a permanent 2-3" crown
in them. Too good to toss, too bent to use without
modification/adaptation. Could not be used on this job for their
original intent.

Sure they can be used with a bit of a bend in them! Put the long
vertical leg with the crown toward the davit arm, and when you load up
the davit that crown will magically disappear. If not appear on the
other side.

I've been watching this College Calculus & Engineering gab-fest
wondering why nobody has suggested a KISS solution - hang a small
chunk of I-beam off the porch beams and rafters, sticking two or three
feet out over the loading area. Possibly with a couple of added
support legs to concrete footings for insurance, or upgrade the area
by adding another post and footing that matches the existing porch
construction. And you can make a hidden gate in the railing so the
loads don't have to go as high.

Use the same hoist for the load but mounted on a roller beam
trolley. Convert the overhanging and swinging loads of that davit arm
system to purely vertical loads of making sure the hoist beam stays
up.

And don't forget a couple of rubber bump stops at the ends for
trolley travel stops, impact loads can cause failure.

A proper use of a davit arm crane is outside where there isn't any
other structure available, and they normally aren't designed for a
support at the top of the post - you transfer all the loads down
through a healthy vertical member to a large footing. You have a very
handy house sitting there - use it.

If you take down the trolley and hoist, all that's visible is the
beam. Ultra Slickness would extend the hoist beam across the porch to
the house wall, and you make a convenient little closet that the hoist
rolls into, with room below for storing the slings straps and spreader
bars. You close a little door and "Presto!" it all disappears.

KISS!

-- Bruce --

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
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