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 | domogala
Join Date: Apr 2004 Posts: 34 Windham, NH 
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2004-05-10 85687
I'm in the process of selecting a backhoe for my tractor. I want to understand the importance of a couple of the "forces" that backhoe spec sheets list. They all list dipperstick digging force and bucket digging force.
I have three different backhoe models to choose from. The first two are 7' hoes, with the main difference between them being the force values. Here's the values:
Unit1:
depth = 7'
Bucket = 2980 lbs.
Dipperstick = 1480 lbs.
Cost = $5499
Unit2:
depth = 7.5'
Bucket = 2600 lbs.
Dipperstick = 1780 lbs.
cost = $6500
So the one with more bucket force has less dipperstick force.
Now for $1200 more I can get:
Unit 3:
depth = 8'
Bucket = 3380 lbs.
Dipperstick = 2240 lbs.
There isn't much more bucket force but there's a lot more dipperstick force. If bucket force is a primary factor then I would think that the extra $1200 is not going to get me that much.
So, which is the primary force that affects how well the backhoe operates, and which model do you think is the best bang for the buck?
Let me add that my primary use of the backhoe would be for digging out stumps, trenching and rock removal.
Opinions, please.
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 | kwschumm
Join Date: Feb 2003 Posts: 5764 NW Oregon 
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2004-05-10 85690
Bear in mind I'm a backhoe newbie, having my hoe for only a few weeks. You can dig with the bucket, or you can dig with the dipperstick, or you can use a combination of both. So the fact that specs are higher on one than the other doesn't necessarily imply more capability, but may dictate your technique when you get into tougher situations. I use bucket force mostly when digging stumps to rip through roots. When trenching the dipperstick gets used a bit more. One thing though, I bought the smaller model 47 backhoe for my JD 4310 and it has plenty of power to drag the tractor all over the place if I'm not careful. A bigger hoe would add even more stress to the tractor. With these smaller machines I'd be sort of inclined to go with the smaller unit to reduce stresses and simply be a little more patient and use careful techniques when digging. ....
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 | DRankin
Join Date: Jan 2000 Posts: 5116 Northern Nevada
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2004-05-10 85726
Well said, Ken. I quite agree.
BTW, What do you think of a 9 inch bucket now? ....
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| kwschumm
Join Date: Feb 2003 Posts: 5764 NW Oregon
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2004-05-10 85727
Mark, the 13 inch bucket is a pretty good size. Sometimes I'm pulling out a little 3-4" stump and I'd like something smaller to leave a smaller hole, but even if I had a nine incher I'm sure I wouldn't take the time to swap over. ....
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 | lamarbur
Join Date: Jul 2003 Posts: 93 Ma/Ct state area
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2004-05-11 85759
My suggestion would be to pick number three. The extra 1/2 ft reach comes in handy more times than you can imagine. It helps by not having to move tractor constantly or at least almost constantly. I have a Bradco and it has 5676 dipper force and 3056 bucket. The curl in the bucket is where most work is done. That extra 1200.00 willl come back in your favor more times than one can count. If you are brand new at backhoes, then you probably won't know the difference, but, it is substantial to say the least. ....
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 | jeff r
Join Date: Jul 2003 Posts: 428 burton. michigan
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2004-05-13 85973
Leaving all the force figures aside, what is the cylinder diameter and the working hydro pressure of the tractor? Looks to me we are dealing with bigger or smaller cylinders. Are we dealing with a separate PTO hydro pump here for this backhoe??? If we aren't dealing with a separate PTO hydro pump of known psi, how could the backhoe's manufacturer quote force figures when he wouldn't know what tractor the backhoe would be going on and therefore wouldn't know what the that particular tractor's hydro pressure was. A 2 inch diameter hydro cylinder will push more pounds with a 2500 psi than a 1500 psi. In hydraulics it is all about diameter of the cylinder, psi of hydro fluid, and volume of the hydro pump. ....
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| jeff r
Join Date: Jul 2003 Posts: 428 burton. michigan
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2004-05-13 85974
LAmarbur,
I thick you got your dipper and bucket force figures switched around. Bucket Force figures are ALWAYS higher than dipper numbers because of the mechanical advantage in the bucket pivot leverage points. Due to that advantage many backhoes mfgs have a smaller hydro cylinder on the bucket than the dipper.
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| lamarbur
Join Date: Jul 2003 Posts: 93 Ma/Ct state area
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2004-05-13 85976
Yes, I did transpose the two numbers. Still, very, very powerful hoe, enough that it made believers out of some local guys who thought their brand far superior. One of them right as I type this is having is year old TN 75 cab turbo New Holland with its superior hoe, having all his hoe cylinders rebuilt. I've done thousands of hours running a JD 710 hoe's in the last 30 years. For a small compact tractor I have yet to try some popular and major brands that can out do the Bradco. ....
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| jeff r
Join Date: Jul 2003 Posts: 428 burton. michigan
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2004-05-13 85977
MY Praire Dog 7.5 backhoe has 3,100lbs at the bucket and 2250 at the dipper according to mfg's WRITTEN specs Which are not always true. After I put a hydro pressure gauge on the hydro pump I found hydro pressure was 1800 psi...So being the little "MOD" guy that I am...... I tweeked the master relief valve to a shade over 2300, which is an extra 500 psi. You do the math and tell me what new force figures I have now. pressure multiplied by the diameter of the cylinder= FORCE
Diameter = PiRsquared
HEY GUYS, LOL, Now that I am thinking about it, I have two calibrated 10,000 and 20,000 lbs +-1% load cells thaT I CHECK TENSILE test machines, and I could have the lab make up some heavy duty pull rings and see what the hoe really pulls. Who wants to bet that mfg's overstate backhoe force figures? I could hook the load cell right on the teeth of the bucket and pull against a tree and get a LBS. reading right where you want it. I think I'm going to do that. Plus I want to know the total weight of my Ariens GT14 garden tractor is anyway and my dump trailer. Gimme a couple weeks. ....
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| hardwood
Join Date: Dec 2002 Posts: 3583 iowa
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2004-05-13 85986
jeffR; Hey you're getting way to serious about all this, around here PiR round / corn bread R square. Have a great evening. Frank. ....
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| stevenc
Join Date: Jul 2003 Posts: 190 North Carolina
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2004-05-13 86013
just be SURE,,you get a subframe,,just a fact or you will end up with 2 1/2's,,it will break the tractor in half ....
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