# Power/Force of hydraulic cylinder???

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• posted on January 20, 2011, 9:30 pm
dpb wrote: ...

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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...
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• posted on January 21, 2011, 2:02 am

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• posted on January 21, 2011, 2:30 am
RBM wrote: ...

Chuckle...mine, too!!! :)
The earlier question got me wondering about what was the vertical component in actual fact -- I was surprised to realize the lift cylinders are only 8 degrees above horizontal when the bucket is on the ground.
If it hadn't been such an ugly day out I'm sure I wouldn't have actually done it...
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• posted on January 23, 2011, 8:44 pm
dpb wrote:

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... the angle ALU is 96.4. ...

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... the lift at _E_ ...

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Coupla' typos noted above and here are a coupla' pictures took while "gathering up" in preparation of loadout. First is just shot of bales as rolled; second shows a couple of piles. Each group is a stack of 34, what'll go on a flatbed so can load at one time instead of having to go gather up while loading. The last is the home place; can just barely see the house thru the cedars/and two largest elms...a little white siding shows through.
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• posted on January 23, 2011, 11:05 pm

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• posted on January 23, 2011, 11:26 pm
RBM wrote:
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:)
Located far SW KS, just about 50 mi from CO right on OK line.
It is pretty country when it rains; we'd had a nice one in late August and another in early in Sept about two weeks before those were taken so stuff had had time to green up nicely after swathing. I hadn't realized the date wasn't set on the camera and intended to reset it but forgot about it. Those were taken about 10 Sept last fall.
Unfortunately, that was also about the last moisture we've had since; it's serious dry at the moment. The winter wheat is in poor shape where got it in and up at all.
We've missed out on all the snows except for just a couple that gave us only a dusting to a short inch each; all the actual moisture has been north/east or south. That's a fairly typical problem out here particularly in the La Nina pattern that tends to form a ridge of high pressure over the western High Plains that pushes the jet stream/storm track around to the east/north.
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• posted on January 17, 2011, 2:25 am

And the cyl might have a 18" stroke, and the loader might lift the bucket 180 inches. This means, forgetting the weight of the arms and buckets for a minute, you would only have a 1480 lb lifting capacity. 10:1 lift ratio means 1:10 load ratio.
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• posted on January 17, 2011, 2:21 am
On Sun, 16 Jan 2011 18:04:22 -0600, snipped-for-privacy@none.com wrote:

That is due to the leverage. You have a "negative" ratio.
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• posted on January 17, 2011, 3:01 am

I'm not sure what point you are trying to make, if any. In a typical loader design, the cylinders act through a lever an fulcrum with a negative mechanical force advantage. Even if the cylinder develops a force of say 10 tons, the force available at the end of the loader arms will be significantly less. Usually the geometry of a loader or backhoe design has the maximum mechanical advantage available in curling the bucket.
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Better to be stuck up in a tree than tied to one.

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar.org