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RockSet N' Grade
10-06-2007, 10:16 AM
I am comparing machine specs. I know this has been talked about before, but I still do not completely understand. Machine #1: Max bucket dig force: 15,311. Machine #1:Max arm dig force: 7507. Machine #2: Max bucket dig force:10,900. Machine #2: Max arm dig force: 8150. So for me alot of questions arise: Is there a formula to calculate these two numbers to come to a variable to fairly compare different machines? Is there a universally accepted method to calculate bucket dig force or do different manufacturers calc it differently? I am trying to level the playing field here on the published spec sheets from different manufacturers and have not been able to get the straight scoop.

ksss
10-06-2007, 04:23 PM
Tigerrotor knows this stuff better than most and hopefully will correct me if I am wrong. The bucket breakout (excavators) is rated with a bucket of choice which is usually a bucket that has a short tip radius for max power. The arm dig force or sometimes called crowd force is the force generated by crowding the arm toward the machine. Some machines have higher bucket breakout and less crowd force. Other OEMs go the other way. As a result some machines are better bucket diggers than others. High crowd forces I think are an advantage in trenching allowing you to fill the bucket easier while pulling a level plane. If you compare the bucket and arm crowd force of different machines you will see what I mean. TK machines seem to be more bucket diggers as their bucket breakout forces are higher. Bobcat seems to be more of an arm digger as their crowed forces are higher.

Gravel Rat
10-06-2007, 05:04 PM
What KSSS says is true I noticed it running 3 different brands of excavators the Komatsu seemed to have the most crowd force the machine would always want to stand on its nose when you hook a rock and start pulling.

The Hitachi seemed to have the best of both worlds and the Deere you really had to work the bucket.

It is interesting to see that Takeuchi has a higher bucket force that may explain the reason why one of the local utility companies prefers Takeuchi minis. They dig alot of power pole holes in a year and with power pole holes your digging a hole where your taking a scoop and lifting it out.

Tigerotor77W
10-06-2007, 05:58 PM
KSSS isn't telling any lies with his analysis of breakout force.

I'd say that Cat is also a stick-digger -- the speed that I could "stick-load" a 305C CR's bucket impressed me to no end. I never even had to work the stick; it would just move the material.

RockSet N' Grade
10-06-2007, 06:09 PM
I understand the above posts and possible qualities of both. I was hoping Tigerotor that there may be a calculation that could be done with those basic numbers to give a rating to compare machines that the guys who design these things use to compare" theirs " to the competition.

SiteSolutions
10-06-2007, 06:51 PM
The Hitachi seemed to have the best of both worlds and the Deere you really had to work the bucket.


I thought the Deere was made by Hitachi?

Tigerotor77W
10-06-2007, 08:51 PM
RockSet: mmm, I think I understand your question. Sorry about that.

The issue with comparing the actual numbers is, as KSSS pointed out, that a manufacturer may use different buckets to get those numbers. There is no standard "SAE bucket" for each size-class of machine for the manufacturers to use, so even though the calculations used to arrive at the numbers are likely similar, there isn't a way to guarantee that the actual numbers involved are comparable.

There isn't a quick way to calculate the combined force of the bucket and stick forces. You can add them vectorally, but this is no easy process... it'd be a very ugly equation, most likely, with several terms.

ksss
10-06-2007, 09:33 PM
To complicate matters, by adding a quick coupler you also lessen your breakout numbers (there are coupler OEMs that claim their coupler does not affect the breakout force). Also the buckets that are used to achieve max. breakout are not necessarily that are the most productive for excavation. All the more important to demo a machine with the configuration that you are likely to use it under. The distance from the tip of the teeth to the top of the bucket is the key. The shorter the distance the more power, of course this typically means less capacity.

Gravel Rat
10-06-2007, 11:35 PM
SiteSolutions the machines are before Hitachi and Deere were sleeping with each other. I'am not the only one that noticed the Deere didn't have the crowed force.

Kobelco machines really have the crowed force or they seem to have. The one of the contractors has a couple Kobelco hoes and watch them work you pull the stick in towards the machine and it drags the machine.

RockSet N' Grade
10-07-2007, 12:52 AM
Tigerotor........thanks.....So, the bottom line as I see it, is there is no set standard and you can arrive at your particular machines numbers any way that you want to. Choose a particular bucket that gives you great numbers, yet is not practical in real application........So published numbers are not necessarily apples to apples.

SiteSolutions
10-07-2007, 01:31 AM
Komatsu seemed to have the most crowd force the machine would always want to stand on its nose when you hook a rock and start pulling.

The one of the contractors has a couple Kobelco hoes and watch them work you pull the stick in towards the machine and it drags the machine.


Seems like that could mean they don't weigh enough. I would rather pull dirt up than pull me down / around.

Tigerotor77W
10-07-2007, 01:26 PM
So published numbers are not necessarily apples to apples.

Correct... they rarely are. If the SAE/ISO could specify a specific bucket, or say that, okay everyone is going to test their machines with the same Bradco buckets, we'd have a better idea.

Even then, though, how material goes into the bucket can be a factor as well. For instance, the Komatsu D155-6 SigmaDozer blade is far more effective than a standard SU blade -- so even if you just swapped blades of the same physical dimensions (length, width, height), the Sigma blade would move material more efficiently.

So in effect, as you said, numbers can't be the be-all, end-all for purchasing decisions for *force* generation. They do give a general idea, however, and can put you in the ballpark. They just won't be "perfect."

turfquip
10-07-2007, 02:51 PM
I understand the above posts and possible qualities of both. I was hoping Tigerotor that there may be a calculation that could be done with those basic numbers to give a rating to compare machines that the guys who design these things use to compare" theirs " to the competition.

Would it be helpful to consider the ratio of break out to crowd force and further, to suggest which ratio would be better for a given task, like pulling stumps or simple trenching?

In other words would a machine with a 2/1 ratio be a better stump puller than a 1.5 to 1?

Just a thought.

Tigerotor77W
10-07-2007, 03:17 PM
Would it be helpful to consider the ratio of break out to crowd force and further, to suggest which ratio would be better for a given task, like pulling stumps or simple trenching?

Not a bad idea -- but when you normalize data, it becomes difficult to compare machines' actual forces. For instance, a 301.5C and a 385C L might have the same ratio (just as an example; I don't know if they do) -- which can only tell you that two machines have the same ratio (but certainly couldn't suggest that 301.5C comes close to matching the production of a 385C!).

That being said, if you're looking for a way to compare the ratio -- as turfquip mentioned -- to figure out the factor by which one force is stronger than the other -- this is a useful derivation.

Construct'O
10-07-2007, 03:34 PM
Correct... they rarely are. If the SAE/ISO could specify a specific bucket, or say that, okay everyone is going to test their machines with the same Bradco buckets, we'd have a better idea.

Even then, though, how material goes into the bucket can be a factor as well. For instance, the Komatsu D155-6 SigmaDozer blade is far more effective than a standard SU blade -- so even if you just swapped blades of the same physical dimensions (length, width, height), the Sigma blade would move material more efficiently.

So in effect, as you said, numbers can't be the be-all, end-all for purchasing decisions for *force* generation. They do give a general idea, however, and can put you in the ballpark. They just won't be "perfect."

Okay !!!!! Whats this?????? I thought we was talking excavators here:confused: Got a picture of Sigma(whatever blade) since you started a new subject!!!! j/k Okay:usflag:

Construct'O
10-07-2007, 03:45 PM
Tigerotor........thanks.....So, the bottom line as I see it, is there is no set standard and you can arrive at your particular machines numbers any way that you want to. Choose a particular bucket that gives you great numbers, yet is not practical in real application........So published numbers are not necessarily apples to apples.

Jimmy Krippers!!!!!!! Just go demo the other brands Rock and forget trying to analyze everything.Throw away that spec book and see for yourself which one does what.

Your going too have a:hammerhead: from reading and figuring out all the math on this one:rolleyes:

Whats the word????? DEMO:cool2: Real slow now demOOOOOOOOOO !:drinkup:

JDSKIDSTEER
10-07-2007, 05:08 PM
I thought the Deere was made by Hitachi?They are the same machine. My brother sells the Hitachi orange machines. look at yhe copyright at the bottom of their web site. http://www.hitachiconstruction.com/en_US/cfd/construction/hitachi_const/excavators/zaxis/zaxis_35u2_general.html

RockSet N' Grade
10-07-2007, 05:47 PM
Constructo.......I be doin' da demo thang! My little two-brain-cells just fired one off in left field and got me to thinkin........and that be a dangerous thing......I am more atune to the concepts of "feel, timing and balance", but every once in a blue moon my linear mind kicks in ( especially when considering a purchase of 100K or so ) and I want to narrow down the field and know the published facts. I am sure this phase too will pass........
I run a 20,000 lb machine and it broke. They brought me a Gehl 602 or 603 zts ( 12k ) to use while mine was in the shop ( again )........and it just didn't have the stability over the sides or power that I need for the jobs I do....Hope to test fly a red/white machine this week ( Takehoochi ) since I am in the Christmas shopping spirit.....

Construct'O
10-07-2007, 07:35 PM
Constructo.......I be doin' da demo thang! My little two-brain-cells just fired one off in left field and got me to thinkin........and that be a dangerous thing......I am more atune to the concepts of "feel, timing and balance", but every once in a blue moon my linear mind kicks in ( especially when considering a purchase of 100K or so ) and I want to narrow down the field and know the published facts. I am sure this phase too will pass........
I run a 20,000 lb machine and it broke. They brought me a Gehl 602 or 603 zts ( 12k ) to use while mine was in the shop ( again )........and it just didn't have the stability over the sides or power that I need for the jobs I do....Hope to test fly a red/white machine this week ( Takehoochi ) since I am in the Christmas shopping spirit.....

I thought your other excavator was Gehl? So what broke that can't be fixed?

Probably better to get the facts before shopping i suppose:dancing:

Will good luck and beeeeeeee!!!!!!!!! sure to keep us informed how things are going.If you need help deciding,i'm sure their is help here for you.:cool2:

O" By the way Merry Christmas!:drinkup: :usflag:

RockSet N' Grade
10-07-2007, 08:13 PM
And that's it in a nutshell Constructo........at what point do you quit "fixing" and give it up for a new machine? Yes, I have an older Gehl 802......replaced just about everything on it, in it except for the superstructure. The list has been endless, and a tad bit spendy. Seems like the oldest thing in that machine now is the driver........Where and when does one call it quits and step into a new machine?

Tigerotor77W
10-07-2007, 08:48 PM
Okay !!!!! Whats this?????? I thought we was talking excavators here:confused: Got a picture of Sigma(whatever blade) since you started a new subject!!!! j/k Okay:usflag:

True -- what I meant was, if you took two blades that had identical capacity and identical width (similar to having two buckets with identical capacity and identical tip radii (radii is the plural of radius)) and ran them both -- even on the same tractor -- there would be a performance difference if one blade was the Sigma blade.

In other words, whether it's buckets or blades, even ones with the same shipping dimensions won't necessarily give the same performance due to differences in contour etc.

RockSet N' Grade
10-07-2007, 10:08 PM
Thanks Tigerotor........I was just looking for some consistency in understanding "published info".

Construct'O
10-08-2007, 12:10 AM
True -- what I meant was, if you took two blades that had identical capacity and identical width (similar to having two buckets with identical capacity and identical tip radii (radii is the plural of radius)) and ran them both -- even on the same tractor -- there would be a performance difference if one blade was the Sigma blade.

In other words, whether it's buckets or blades, even ones with the same shipping dimensions won't necessarily give the same performance due to differences in contour etc.

Well,had to go to the internet for a look see.Different looking for sure.Basicly it is just a different concept to the old u blade that they have had for years as far as i see it.

The u blade carrys more dirt then su blade ,also,great for like coal or large amounts of dry material,but not the best for muddy material.

Just a new sales gimmick,looks like to me.Don't pay any attention to me ,just the old timer coming out in me as usual;) :usflag:

Tigerotor77W
10-08-2007, 01:38 AM
Well,had to go to the internet for a look see.Different looking for sure.Basicly it is just a different concept to the old u blade that they have had for years as far as i see it.

Just a new sales gimmick,looks like to me.

Oops! Forgot to post a picture.

And could well be a sales gimmick. ;) We know I love quoting those.

RockSet, sorry for not being able to give you anything to work with... hopefully demos will help enough.

cddva
10-19-2007, 01:00 AM
You guys sure get on a roll sometimes!!! If the dirt diggin' ever gets to be too much I think a few comedy clubs would be glad to have you entertain the clientele!
God help us if RockSet gets a Takehoochi...... who's going to represent the "other" brands here?!!:rolleyes:

RockSet N' Grade
10-20-2007, 12:25 AM
KSSS, I have a feeling, will still be a big fan of "Faded Orange", opps........I mean Power Tan! If we could only entice Bill Schwab to come back here for a moment or so, he and KSSS could give us some great debates on unlimited subjects. In the meantime, I am waiting for my new hooked on phonics series to arrive :)

ksss
10-20-2007, 01:40 AM
I am also a fan of red and white/grey. However the Power Tan runs pretty deep. If your "Hooked on Phonics" fails to show let me know, I still have my copy.;)