LD1
Epic Contributor
That's a really good point.
I have some hydraulic novice questions:
Is there a way to calculate "reserve capacity" when operating the FEL to see if the tractor has enough GPM to operate the loader and 3rd function simultaneously? Like by taking the cycle time of the loader cylinders and their volume to calculate how much fluid they use per second?
Is the chain a strict priority? I.e. cylinders on the first valve get all the flow they can use and only the remainder goes to the next in line? Or are the connections from one valve in the chain to the next more like a tee, so cylinders on the first and second valves share flow equally? Or some combination of the two depending on flow restrictions in the system? Maybe it does not matter.
Its not a simple calculation based on GPM.
Hydraulic oil, if you are trying to command it to do multiple functions, is gonna take the path of least resistance.
Raising a loader that is empty, takes about 500-600psi on most machines. Dumping the loader or opening the grapple takes far less. Even closing the grapple takes far less until it actually starts to clamp down. So if you try all three of those at the same time, odds are the loader lift is gonna be pretty sluggish, at least until the grapple closes or you stop dumping.
Same way with power beyond. With the loader being the first in line, and your 3PH usually at the end of the line. Whatever reserve is left goes to the 3PH last. IF you try raising your loader and 3PH at the same time the front end loader is certainly gonna lift because it is first in line. Whatever is left will go to the 3PH. But remember, it only takes500-600psi to raise that loader. Normally that will also be sufficient to raise the 3PH as well, so both will normally move but the 3PH will be at a slower speed.
Now if you have something heavy on the back of the 3PH that "may" require 1500PSI to lift under normal conditions, odds are it isnt gonna lift until you let off the FEL. Because the oil is taking the path of least resistance. And in this case, thats the 600psi required to raise the loader.
Try it sometime. With nothing on the 3PH both the loader and 3PH should lift normally. Now put your heaviest attachment out back and try again.