"Ignoramus15251" wrote in message
...

I would not do it, you will bend the vertical post and that will be
the end of it.

I have a 2 ton Harbor Freight crane with telescoping legs (not
foldable), and it was perfectly high enough to take stuff out of my
pickup truck.

If I was in your situation, I would extend the boom a little, add a
counterweight on the back, and lift less weight than allowed, to
account for longer boom.

i

My engine hoist lifts short items out of the truck OK, but didn't work for
my lathe (reaching to center of gravity over the lathe) or my vertical air
compressor, having 4WD truck doesn't help.

Currently the vertical post has a hydraulic jack attached, either 5 ton or 8
ton. I don't see that attaching a boom to that point and running it mostly
vertical, keeping the load within the range of the wheels, is going to
increase the bending forces on the vertical post. My goal is to increase
the vertical height, not the load rating or ability to reach further out.
The tension from the hoist cables would be attached very near the support
braces, this would put the braces in tension just as they are currently when
lifting.

But if somehow having a long boom attached to where the bottom of the
hydraulic cylinder currently attaches would cause more bending force on the
vertical post, what about the current configuration with the boom lengthened
and pointed up near vertical? For example if a 1000lb load was out 24" from
the vertical post, a horizontal boom X component would be 1 (COS of zero
degrees), if that same load was still 24" out but the boom was 60 degrees,
the X component would be 0.5 but on a longer boom. I'm not saying the load
capacity would be exactly the same but it would be nice if I could unload
taller item from my pickup truck and perhaps even items from a tractor
trailer truck. Of course if I get a shop built here and get my forklift
moved over here it won't be an issue.

RogerN