dpb wrote:
....
OK, I went and dug up the operator's manual off the JD148 that's on the
4440 as the loader tractor here...

....
It's hydraulics are 2250 psi, lift cylinders are 2.5" bore/1.75" rod --
from which one can estimate max lift force at the lift pin of sotoo
11000 lbf. The published breakout lift force is "only" 4700 lbf in
comparison. ...

OK, just for grins on a cold, damp day...

I went out and measured the hinge point distances and the overall length
of the moment arm to the end of the lift arms (accounting for the angle,
measuring to the extended straight line from the fixed pin thru the
upper cylinder lifting point).

When down at ground level, the pertinent dimensions and angles are --

Well, let's see if I can do enough ASCII art to get a picture as crude
as it will be for referencing to...


Arm pin (A) Cylinder Pin (U)
X --------------X--------O End actuator attach pin (E)
|
|
--X Lower cylinder pin (L)

The (nearly) closed cylinder length at ground level (L-U) is 42"

Solving the small right triangle to the left of L we find the angle from
the horizontal to the line A-L is 75.5deg. Using the law of cosines
the angle ALE is 96.4. The cylinder lift angle is the complement of
these two or 180-(75.5+96.4) = 8.1deg.

The vertical component at U is then 11000*sin(8.1) == 1550 lb

Balancing the moment I got that the lift at U was 2200 lb, within 10% of
the 2350-lb breakaway spec (remember this is looking at only the one
cylinder).

FWIW (which ain't a lot, but it was cold, damp and blustery enough
yesterday I didn't try to do much outside).

Unfortunately, the photo bucket site didn't let me log on yesterday and
I couldn't get a flickr acc't to go thru either so gave up on the
posting of the pictures for the moment...

--