Hydrostatic quirk or total nonsense?

[sunandsand]

Copy of Family Handyman arrived today, it has an article which touches on a BX2380. Author says he was having trouble filling the bucket on the FEL, and needed a bit more horsepower. He said when he pressed down hard on the "forward" pedal, it "essentially shifted into a higher gear range" which wasn't what he wanted and bogged the engine down. His solution was to shift to 4WD low and try again, which he said solved the problem (I guess more mechanical advantage from a lower range). He wasn't clear if he was having problems filling the bucket by shoving it into the dirt pile, or filling the bucket by push/curl/lift (which I think is the proper procedure since using the FEL as though it was a bulldozer will bend it).

So . . . I have a B2601 with pallet forks. I have sometimes run into problems lifting "stuff" which I know weighs less than the FEL rating. The engine doesn't bog, but the FEL won't lift. I was unloading freight on pallets out of a tractor-trailer, and the FEL wouldn't lift, but it would curl, and that gave me enough clearance to get the pallet out of the trailer, back away, and lower the pallet to the ground.

My question is this - would I have had more lift capacity if I were in low range (I was in medium, 2WD) or did I just happen to find the lift limit of my FEL? Would the gear range affect the output of the hydraulic pump with drives the FEL? I also think the lift capacity of the FEL varies with the height, and the truck bed is 4' off the ground, maybe a little more.

His explanation might also be apples and oranges - if he was playing bulldozer, that shouldn't affect the hydraulics, and he simply asked more of the BX than it could deliver in high range.

Best Regards,

Mike/Florida

 

[newbury]

weighs less than the FEL rating.

But is your system up to spec?
In the past it has been reported that some dealers routinely set their loaders below spec, sometimes as much as 10%. Fewer warranty issues and most people never check their hydraulic pressure.

 

[sunandsand]

But is your system up to spec?
In the past it has been reported that some dealers routinely set their loaders below spec, sometimes as much as 10%. Fewer warranty issues and most people never check their hydraulic pressure.

Don't know . . . how can I check it?

Considering that a LOT of people routinely beat the mortal you-know-what out of things they own, even though they know better (or should), that dealer policy might not be such a bad idea ;-)

 

[4570Man]

It’s operator error. The HST pedal works differently from a car accelerator. You want more throttle and less pedal when the going gets tough. The tractor should have already been in low range which it sounds like it wasn’t.

 

[JWR]

Mike: The Handyman Author gave a misleading article. First, it does not shift into any range. Only the operator shifts to a different range. Certainly he got more forward motion force when HE shifted to low range (which happened to be how he was filling his bucket.) Then you add more mud to the water saying "he might bend the FEL." That is not going to happen. The BX does not begin to have enough traction or power to bend the FEL. The FEL will win that battle all the time.
Then your question: Would you have more lift capacity [with the FEL] if you were in low range ? Answer is NO. In both his tale and yours the range the HST is in does not materially affect the lift capacity of the FEL. That's the simple answer.

Now to clarify a bit: the FEL (or anything else driven via the hydraulic pump) will have more lift capacity at higher rpm. So if either of you lug down the engine rpm by whatever means (such as by lugging it down being in a high range while trying to move forward) then, YES, you would have 'reduced the lift' but that is a misleading rationalization (rationalization is substituting A reason for THE reason.)

Look at it this way, if you stop the tractor, run the engine at rated full rpm, and keep adding weight until the FEL won't lift it anymore that weight will be the same regardless of what range your transmission is in. Including neutral which it is in anyway with your foot off the pedals.

 

[oldnslo]

To answer your question the gear you are in has zero effect on what your loader will lift. With forks the center of the load is potentially farther forward which will reduce the theoretical lift capacity.

And pushing harder on the HST pedals tries to make the tractor go faster Vs giving the tractor more power. This is a misconception that some people have.

 

[Smokeydog]

Chart shows where the position the weight is on forks effects lift.

The curl has breakout force. Caution as this can add to your total lift force.

 

[sunandsand]

OK, this clarifies things immensely.

1) FH writer misunderstands the HST system. He will be happy to know the BX doesn't have enough grunt to bend the FEL. (My neighbor has managed to bend his by abusing it, but it is a much larger tractor.)

2) Hydraulic pump operation is not affected by speed range, and I'm not moving anyway when I'm trying to lift the pallets.

3) Throttle was at full power (on mine, I don't know where his was).

4) I found the lift capacity at height X, and cheated it just a tad with the curl function.

5) The membership of TBN is the *BEST* source of information there is!

Thank you!

Best Regards,

Mike/Florida

 

[IndyIan]

There is a tendency to scoop from the bottom of the pile while driving forward so you are trying to lift way more than a bucketful and if you are in 4wd there's not going to be any wheelspin either, so you can easily run out of pushing power in medium range and start to bypass the HST hydraulics. I'm not sure how many hp it takes to send the load hydraulics into bypass but its several as well which pulls down the rpms a bit too.

 

[jeff9366]

I was unloading freight on pallets out of a tractor-trailer, and the FEL wouldn't lift, but it would curl, and that gave me enough clearance to get the pallet out of the trailer, back away, and lower the pallet to the ground. The truck bed is 4' off the ground, maybe a little more.

It is much safer in max lift unloading situations to raise the load an inch, then have the someone drive the truck out from under the load, then lower the load with the tractor stationary.

That initial 60" of tractor movement at max lift is the most dangerous time, when tractor rollovers occur.

 

[jeff9366]

Now to clarify a bit: the FEL (or anything else driven via the hydraulic pump) will have more lift capacity at higher rpm.

This is incorrect. Increasing engine RPMs increases speed of FEL movement in feet-per-second but does not increase lift capacity in pounds.

 

[Egon]

The original article was total nonsense.

 

[Jims1025R]

4) I found the lift capacity at height X, and cheated it just a tad with the curl function.

Bear in mind that the "capacity" and lift ability are not always the same for a loader (bucket or forks). The geometry of the various angles of loader arms, bucket/forks position, and hydraulic cylinders means that there will be different lift ability based upon all of these angles, where the "capacity" will be the most conservative of the lift ability. This is not a suggestion that the capacity should ever be exceeded, and a well set up system will bypass hydraulic pressure, before capacity is exceeded (so the lift seems to stall). So you may feel that you have a little more power to load or lift a little with the loader/bucket/forks in certain positions, but the lift cannot be continued (at all, or safely). When you're operating in this range, you're pushing your luck - particularly when fork lifting something out of a truck and down to the ground. At least loading up can warn you and you can return the load to the ground.

Increasing engine RPMs increases speed of FEL movement in feet-per-second but does not increase lift capacity in pounds.

Correct. Increasing engine speed will increase hydraulic pump speed, and thus hydraulic speed. The maximum hydraulic pressure is limited by pump efficiency and hydraulic relief setting. If you are driving at any speed, particularly in high range, that is consuming some engine power, and may reduce hydraulic lift ability. If you are driving at anything other than a slow approach speed while operating hydraulics to their lift capacity, you're pushing your luck - drive or lift, avoid doing both at once!

I built a three point hydraulic log splitter for my JD tractor decades back. I plumbed in a log splitter valve to the tractor to power it. (The first valve had a kick out return, which made the tractor loader unsafe - separate story). The splitter worked, but not great. I used it - fine.... The I bought a dump trailer from the JD dealer for the tractor, with the agreement that it would "dump anything!". No, it wouldn't lift and dump a load. I investigated... There was an un marked pressure relief bypass in the splitter valve. I put a hydraulic pressure gauge on the valve output ('should have done that at installation!) and reset the relief pressure to that of the tractor system (it had been less than half). Well, the dump trailer became a near catapult, and the splitter would split the big maple after all!

If in doubt, ask your dealer to check the hydraulic system pressure and relief setting, and give you a little more review of how the hydraulic attachments work...

 

[mikester]

NOTE TO OP

Your SCUT is NOT a skidsteer. Your SCUT is NOT a forklift.

Rated lift capacity for your machine is at the pins without bucket or forks. Your lift capacity changes based on the height of your lift. Your max lift is near the ground, is lower at 4 feet, is lowest at max height.

Put on forks, deduct the fork weight from your lift capacity. Same for the bucket. The further your load is from the pins, the less you can lift.

Digging from the ground or a pile is hard work. Digging from the bottom of the pile is even harder work for any machine. Your machine wasn't designed for this work.

Bottom line is if your machine can't lift or push something then you are using the wrong machine and/or you have wrong expectations.

 

[Diggin It]

So . . . I have a B2601 with pallet forks. I have sometimes run into problems lifting "stuff" which I know weighs less than the FEL rating. The engine doesn't bog, but the FEL won't lift. I was unloading freight on pallets out of a tractor-trailer, and the FEL wouldn't lift, but it would curl, and that gave me enough clearance to get the pallet out of the trailer, back away, and lower the pallet to the ground.

What do the forks weigh? Rated lift capacity might be without either bucket or forks.

How far forward of the pins was the load? Closer in, more lift. Farther out, less lift.

Digging from the ground or a pile is hard work. Digging from the bottom of the pile is even harder work for any machine.

I've also found I can curl more than I can lift. That helps when 'breaking out' of a pile of gravel. Move in, curl to break, then lift. Something about using the heel of the bucket for leverage I guess.

 

[jeff9366]

Bottom line is if your machine can't lift or push something then you are using the wrong machine and/or you have wrong expectations.

BUY ENOUGH TRACTOR​

 

[sunandsand]

I was unloading freight on pallets out of a tractor-trailer, and the FEL wouldn't lift, but it would curl, and that gave me enough clearance to get the pallet out of the trailer, back away, and lower the pallet to the ground. The truck bed is 4' off the ground, maybe a little more.

It is much safer in max lift unloading situations to raise the load an inch, then have the someone drive the truck out from under the load, then lower the load with the tractor stationary.

That initial 60" of tractor movement at max lift is the most dangerous time, when tractor rollovers occur.

Absolutely agree.

Tractor-trailer guy arrived, opened the roll-up door at the back, went to the cab and went to sleep. He's done until we're done. (Standard trucking company policy). I was and I am very, very careful to back STRAIGHT out, on a firm and level surface, and then get the load down as expeditiously as possible. Then, once the load is safely down, a few inches off the ground, I'll start driving it around into the warehouse.

I have a bigger problem with "helpers". Dear Bride likes to take photos of this in progress. I tell her to back up, and she does - about two feet. I tell her to back up again, she gets mad. (Better mad than hurt or dead.) I had someone walk between the tractor and the trailer, I yelled at him not to do that, you wanna get hurt? and five minutes later he did it again. I have to "control" the work space, and sometimes people just. don't. listen.

Best regards,

Mike/Florida

 

[sunandsand]

The pallet forks weigh about 100 pounds - they're from Everything Attachments. The pallets are "euro" pallets, which are slightly smaller than standard US pallets.

I don't anticipate this occurring again. I get two containers a year from overseas. Usually, the contents are fabric and wood items and are light. This time, he decided to also send some pottery items, which is basically rocks. His consideration is to fill the container, he needs to "cube it out" to minimize his per-item freight costs. What he did this time was "grossed it out", he filled the container with heavy stuff right to the weight limit of the container (and to the weight limit of the lift capacity of my tractor). Normally, I have no problems unloading the usual lighter pallets, but with the much heavier pallets this time . . . well, I did.

(An example of this shipping scrap metal overseas. The container is at max weight (grossed out) with about two feet of scrap metal, above that is only air. If you filled the container to the top, it couldn't be lifted.)

Further, the ocean freight people, the trucking company, the rail connection, UPS, the ultimate consignee, and UPS/FedEx were NOT kind to the pottery. Something like 60% of the items were broken in transit (know anyone who needs a PILE of busted pottery shards?) so he's going back to the much less fragile fabric and wood items for the next shipments.

He also told his packers to put the heavier boxes (with the pottery) on the bottom of each pallet, evidently they didn't listen and some of the pallets were very top-heavy and toppled over when customs opened the container for inspection. They weren't happy either, and just shoved everything back into the box and closed the doors.

(The railroad also took three weeks to move the container 210 miles from Savannah (port of entry) to Jacksonville, which calculates to four tenths of a mile per hour, and then lost it in the rail yard for another two weeks. But that's a different tale of woe . . . )

Best Regards,

Mike/Florida

 

[GeneV]

This is incorrect. Increasing engine RPMs increases speed of FEL movement in feet-per-second but does not increase lift capacity in pounds.

It shouldn't, but yet it does, at least on mine. Most noticeable on the backhoe, lifting up a big log with the thumb.

 

[KWentling]

It shouldn't, but yet it does, at least on mine. Most noticeable on the backhoe, lifting up a big log with the thumb.

That is my experience too with my BX22. At idle I get no movement with either the loader or backhoe. I believe the newer than my BXs were much better in that regard.