using a pressure guage as a scale.

[wjkrostek]

We are over thinking this. All I want to know is what pressures I can expect lifting one ton bag of fertilizer. I was using 1 sq inch as an example of having two cylinders does it kind of double the lifting power. using your 4 sq inch. 2000lbs / 4 =500PSI ?divide that by 2 and it will only take 250 psi to lift 2000 lbs. it just doesn't seem like my thinking is right. Seems to me That's not what I'm going to see. What gauge do I need. The less would be more accurate for reading. Thanks

 

[CincyFlyer]

But what's the max pressure? that's what I'm trying to find out. If I have two cylinders each with one sq inch total 2 sq inches. I should be able to pick that up with 1000 psi. Am I think right?

Well, you don't. If you have puny 2" cylinders, each one will have 3.14 square inches, giving you 6.28 square inches for the pair.

 

[4570Man]

What's the max pressure of your system and the rated capacity of the loaders?

 

[LD1]

We aren't over thinking anything. You are by trying to bring math into the equation which you don't understand. (And attempts to explain only seem to confuse you).

And why are you referring to the number of cylinders? And doubling them doubles the capacity??? Forget all that. You have a modern loader, it has two cylinders. Forget everything else. Forget how many square inches each is.

You want to know what pressure is required to lift a ton.....simple. put a gauge on the system, and lift a ton. Now you know.

 

[4570Man]

You want to know what pressure is required to lift a ton.....simple. put a gauge on the system, and lift a ton. Now you know.

Which is only a useful number if you're lifting the next ton with exactly the same weight distribution, but we've already been through that.

 

[Industrial Toys]

As I mentioned earlier in an EDIT.

I am quite certain that a gauge with suitable working pressure will not give you the required resolution to see the addition of a feed bag. Maybe a load of aggregate.

 

[4570Man]

Yes it will. There is no leverage over the cylinder (lift cylinder that is) by moving the load further forward.

Tilt cylinders are a different story. Further out or higher up and their capacity is reduced

That's what I thought. Not that it actually matters. The hydraulics on a forklift are way stronger than what the machine can handle. It tips forward long before the hydraulics give up. Moving the load forward significantly decreases the tipping load.

 

[mike69440]

If you chart 4 points you will be accurate, 5 very accurate, use French curve to connect dots or Excel

 

[4570Man]

If you chart 4 points you will be accurate, 5 very accurate, use French curve to connect dots or Excel

Only on the height of the loader. You've still got the distance from the pins to contend with and the distribution of the load.

 

[wjkrostek]

If I had a gauge I'd put it on but I don't. So what I was assuming someone out there did this already and would know what psi gauge works best. As the smaller ones would give me an easy read I didn't want to buy a 5000 psi and find out the reading is only hundreds and not thousands. I guess I can't get my idea across to you all. I'm done. Thanks for your time.

 

[CincyFlyer]

If I had a gauge I'd put it on but I don't. So what I was assuming someone out there did this already and would know what psi gauge works best. As the smaller ones would give me an easy read I didn't want to buy a 5000 psi and find out the reading is only hundreds and not thousands. I guess I can't get my idea across to you all. I'm done. Thanks for your time.

I know, you quit. But if your system puts out 2200 PSI, your gauge had better be at least that, 'cuz if you top out the loader it's gonna hit it, even empty.

 

[CADplans]

My 584 IH loader operates at 2250 psi (IIRC?),, but, there are times the pressure easily goes to 5,000 or possibly 7,500 psi.

Hit a bump while carrying a load, the pressure spikes WAY up.
Grade the driveway with the bucket, hit a big rock, who knows how high the pressure can go.
Lots of people blow hoses when the loader pressure spikes.

 

[bigdeano]

I would get a digital pressure gauge. They have them pretty cheap on Ebay if you can wait for it to arrive from overseas. It should have better resolution than an analogue gauge. If you take the reading with the loader at the same height each time you should get a pretty accurate weight.

As others have said, calibrate it by lifting a known weight and writing down the pressure. More or less weight will be in direct proportion, except you'll have to subtract the pressure of the loader itself.

 

[LD1]

3000 psi works.
5000psi also works but to a less degree of accuracy.

Yes I have done this. Pressure spikes from bumps with a load rarely go over the 3k.

You don't understand hydraulics, that's clear. That's why we are trying to help.

Get a 3k or 5k and be done

Even if you were wanting to scale loads that resulted I. Under 1000psi on the gauge, you do NOT want to go that low. Because your system pressure is capable of blowing up that gauge.

 

[Rustyiron]

3K vs 5K gauge in this application- would "pegging" a too small gauge ruin the gauge ("blow up") or just stop reading?
I'm kinda thinking it would just have reached it mechanical limits and stop reading pressure.:confused3:

 

[4570Man]

I've exceeded the pressure on air gauges with no problem, but it wasn't by a lot.

 

[bigdeano]

I ruined a hydraulic gauge. Too much pressure deforms the tube in there that bends to move the needle. Don't remember how much the pressure went over. You could put a valve under the gauge to protect it.

 

[the old grind]

I pegged a Bourdon tube gauge for just a second, putting its 50lb range briefly up to a 65 or more PSI burst and recoiled instantly at the 'twang' I heard. :ashamed:

It promptly returned to 20 some lbs indicated and I had to do the usual routine and take the lens and 'can' off out to re-mesh the gears. There was fully one cog too far in either direction from a nice zero, so I seems to have avoided damage to the tube. It looks as though just as the needle was about to bend on the peg the dial's pinion walked off the sector, and slipped back after skipping a few teeth.

You might get a mulligan like me once or twice, but I'd hate to do it again over a beer ... as in to win beer .. :laughing:

I bought a glycerine-filled 3k PSI gauge and 3/8" x 24" pigtail from SS cheap for 2-3k hydro checks. btw, there's no QD or anything, as I never plumb it to the same size fitting twice for a test. Happiness is having a Parker store < 10 min away, and I ain't afraid o' much.

 

[LD1]

You would have a really hard time pegging a 3000psi gauge in a 2500psi or less system. I had a 3k gauge for years on my L3400.

A full bucket load of stone or gravel or mud or dirt or whatever would read in the 1500psi range.

Surges and spikes from driving hardly made a 300psi difference either way.

You would have to load you loader to the max that it could lift (which would make the gauge read in the 2400psi range), and then drive like a mad man over rough terrain to even get a spike over 3k.

 

[Rustyiron]

LD, I think it was you that showed the math on grapple "lid" closing pressure. Is there a big swing in capacity of a loader through out it's motion if any? Beyond the load's position in distance from the loaders point of rotation, it's force will remain the same correct?