Gunner Asch on Wed, 18 May 2011 01:54:09 -0700
typed in rec.crafts.metalworking the following:
On Tue, 17 May 2011 20:37:15 -0500, Ignoramus31865
On 2011-05-18, Pete C. wrote:
I have a GM 3/4 ton pickup.
I won, in an auction, a "Ramco RM5000" crane. This crane is similar to
the Harbor Freight truck crane, but is a lot beefier.
It is pictured he
(not mine, but an identical model).
This is rated for 5k pounds, I am sure for the boom fully retracted.
It has a 8,000 lbs jack. I will put in a longer boom too, and a
winch. I am aware that extending the boom will decrease capacity
proportionally, so a boom that is 4 foot would decrease capacity of
the crane to, say, 1,500 lbs or whatever. I have to call the mfr to
find out. This is stillw ay better than my HF crane.
I have a very large 3/4 inch steel plate, I would say 3x4 feet, that
is rusting in my backyard.
What I thought of doing, is making a cutout on the plate to fit around
a wheel well, and mount it in the back of the truck's bed, and put the
crane on top of it. The Ramco crane would sit in the rear right corner
of the bed, just like this Harbor Freight crane does now:
It has to be a large plate, to spread the weight of the crane and the
levering action that its base would apply to the bed. This particular
plate weighs around 300 lbs and is large enough.
My question is, what sort of constraints do I still have. I would hate
to overturn my truck, break suspension, etc. I would also think that
for heavy lifting, I would need to jack up the right rear wheel too.
Any practical opinions?
A crane with that weight capacity really needs to be mounted to the
frame, not to pickup bed sheetmetal. I think typically it would be
mounted with a beefy bracket under the bed to the frame. A support leg
(trailer jack) for the corner of the truck with the crane is common for
the heavier cranes so you don't apply a concentrated load to the
suspension on one side of the truck and also to stabilize it so it stays
level during the lift instead of tilting to that side.
What I was going to do is put a steel plate, 3x4 feet or so, on the
bed and bolt it to the bed. Would that not be enough support for the
crane? I already have this plate and it is huge.
That plate HAS to be bolted to the frame. Period
Amazing how flexible truck beds can be. Especially to the torque
of an asymmetrical load.
No matter how thick it is.
Oh I don't know, a bed whcih is six inches thick _might_ hold.
Then again, the whole bed might also just come loose from the
frame, from the torque.
We will drink no whiskey before its nine.
It's eight fifty eight. Close enough!