B7100 Hydraulic block diverter (70060-00360 or 70070-00385)

torch

Well-known member

Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Jun 10, 2016
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Muskoka, Ont.
I seriously doubt thats going to be a problem. When extending a DA cylinder all you lose is the volume of the rod. My little B7200 has no problems with my 4 x 24 log splitter cylinder. The 1.5" rod displaces 42 cubic inches = .75 quarts.

Dan
Well he does call it a "bidirectional cylinder". But when he says "manual pump" I'm not so sure it's double acting. And i am curious what size cylinder it takes to lift a 400 lb load on the end of a 26' long lever that weighs another 1,700 lbs.

Is there a hose to each end of the cylinder?

Let us suppose that the pump delivers 0.3 cu. in. per stroke. And let us suppose that the operator can pump it 30 strokes per minute. Over 45 minutes, that would be about 6-1/2 litres of fluid. Definitely more than should be drawn out of the tractor.

That would be consistent with a 20" stroke length in a 5" cylinder. A 2" diameter rod could be expected in that size, so even a double acting cylinder would drop the reservoir 2 litres. Well below the add mark on the dipstick.

Of course, I'm making a lot of suppositions here. Maybe the 45 minute estimate is based on 10 or 15 strokes per minute, or maybe the pump only delivers 0.05 or 0.1 cu. in. per stroke. And the angle will make a big difference -- even a 1-1/2" cylinder could lift that weight IF it starts off pushing straight up. As the tower tilts towards vertical, the downward force would be reduced. Possibly at the same rate the cylinder lifting force is reduced as it tilts towards the base.

That's why it would be nice to have real data.

The other issue that comes to mind is pressure. A quick look at Enerpac's website suggests their manual pumps can deliver anywhere from 5,000 to 10,000 psi. So the existing cylinder may not be big enough to lift the load when powered from a 1,700 psi tractor hydraulic pump.
 

torch

Well-known member

Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Jun 10, 2016
2,583
831
113
Muskoka, Ont.
How often will you be raising and lowering this thing anyway?
 

TheOldHokie

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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
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windyridgefarm.us
Well he does call it a "bidirectional cylinder". But when he says "manual pump" I'm not so sure it's double acting. And i am curious what size cylinder it takes to lift a 400 lb load on the end of a 26' long lever that weighs another 1,700 lbs.

Is there a hose to each end of the cylinder?

Let us suppose that the pump delivers 0.3 cu. in. per stroke. And let us suppose that the operator can pump it 30 strokes per minute. Over 45 minutes, that would be about 6-1/2 litres of fluid. Definitely more than should be drawn out of the tractor.

That would be consistent with a 20" stroke length in a 5" cylinder. A 2" diameter rod could be expected in that size, so even a double acting cylinder would drop the reservoir 2 litres. Well below the add mark on the dipstick.

Of course, I'm making a lot of suppositions here. Maybe the 45 minute estimate is based on 10 or 15 strokes per minute, or maybe the pump only delivers 0.05 or 0.1 cu. in. per stroke. And the angle will make a big difference -- even a 1-1/2" cylinder could lift that weight IF it starts off pushing straight up. As the tower tilts towards vertical, the downward force would be reduced. Possibly at the same rate the cylinder lifting force is reduced as it tilts towards the base.

That's why it would be nice to have real data.

The other issue that comes to mind is pressure. A quick look at Enerpac's website suggests their manual pumps can deliver anywhere from 5,000 to 10,000 psi. So the existing cylinder may not be big enough to lift the load when powered from a 1,700 psi tractor hydraulic pump.
Jeez - this started as a simple question of adding hydraulic outlets to his tractor to run a cylinder. I think its clear that is easy and cheap.

If it takes 5-10 thousand PSI to extend his cylinder a PTO pump is not going to do the job either.

He said bidirectional cylinder - i assume he knows what that means.

If not a 4" x 24" single acting cylinder is massive, produces 24,000 LBF @ 2000 PSI, and still only holds a gallon of oil - well within the capability of a B7100.

I am not there and can't evaliate the hydraulic tequirements of his turbine but I think this discussion has definitly jumped the tracks.

Dan
 

torch

Well-known member

Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Jun 10, 2016
2,583
831
113
Muskoka, Ont.
I think this discussion has definitly jumped the tracks.
I agree. Maybe a mod could split this off into it's own thread? I just hate to see the guy go to the time and effort only to discover it won't work.

The angle of the cylinder at the start of the lift will make a huge difference. Remember that with the cylinder as fulcrum, the force required will be approximately twice the total weight -- more actually, since the cylinder will not be in the centre of the tower length. 580 kg x 2 = 2,552 lbs. Vertically (ie 90°), a 1-1/2" cylinder would have no problem with that at 1700psi, at least to start. But if it's starting off at a 10° or 15° angle it will need a 3" or 4" diameter cylinder at tractor pressures.
 
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Jouke

New member

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Kubota B7001, Wood chipper, box, mower
Dec 2, 2023
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0
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Ireland
Thank you all for your inputs and thoughts.
unfortunately I do not yet have possession of this system. it is on a ship on its way from China, ETA half February.
I do not have the specs of the cylinder, but it does have a hydraulic hose on each end.

Your pressure calculations have been very enlightening, but I appreciate your sentiment that the discussion is going beyond Kubota.
I leave it to the mod to move us elsewhere.

If anyone is interested in the details and price of the turbine please pm me.
Jouke