Page 15 of 17 FirstFirst ... 5121314151617 LastLast
Results 141 to 150 of 162
  1. #141
    Super Member
    Join Date
    Feb 2006
    Posts
    8,118
    Location
    VA
    Tractor
    JD2010, Kubota3450,2550, Mahindra 7520 w FEL w Skid Steer QC w/Tilt Tatch, & BH, BX1500

    Default Re: Does HP matter?

    Quote Originally Posted by nomad View Post
    As someone who puts his nose into pure mathematics for a while, I can say that pure mathematicans live in another world. You can call that they belittle pure physicans and even applied mathematicans. Pure mathematicans are really in another worlds. just to give an example. For physicans, there is only one infinity. For a pure mathematican, there are infitine number of infinities. But, they do somethings real even though they themselves are not aware of what they do really and they communicate with physicans and applied mathematicans about what they are doing really, their means in the real life, etc. Sometimes, especially in last decades, big inventions (such as Einstein's general relativity, black holes, etc which are not proved physically yet) were made in pure mathematics first. Anyway, pure mathematicans are in another worlds and the gap between them and common people has increased a lot. But, this is a reason for a pure mathematican to be proud. Common should actually thank a little to physic and applied mathematicans who try to make common understand things in science and mathematics more. That's why we see different expressions of power, force, etc etc. due to their efforts of physic and applied math people, not pure mathematicans at all who live in a world they have built for themselves.

    Anyway, maybe, a new math teaching way is really necessary, maybe, should be started at the beginning. Till 2-3 decades ago, there were philosophy courses at high school, now, which are omitted. For example, without understanding what the force is, we are memorizing it and errors in our understanding are getting bigger in later stages like snowballs. For example, we often said here that force is a static thing. What an average Joe understands from this when it is called static? He'll probably understand that there is no motion. Right, engineers too understand same. But, no motion ideally means timeless, infinitely same state in time. Again, ok. But, then, we should not see "time" in its unit of force then if it is same in "all time". Now, lets look at the unit of force (in si unit system.) It is N, that's, Newton. Now, we don't see time here. See how we are forced to forget its background, hidden time in this unit.. Lets rewrite it explicitly. N = Kg x m / s / s. (here, m/s/s or m/s^2 as you know is unit of change of velocity, or, acceleration.) So, we use time even for a force on a body which always sits on the ground. We say this force is constant, and we call it weight. This is so because of our one assumption we make in our early schools, that's, gravitational acceleration is constant, which is not actually, changes a little depending on its coordinates in the world vertically and horizontally. This is another story, but, I am trying to come to a point.

    If you looked into our talks here, what thing an average Joe noticed? He probably noticed that whenever we divide a quantity by time, we called it power. So, in my words above about the force, now, he noticed that another quantity too is divided by time and he probably thought that force too is power. Technically and mathematically, correct according to grouping math method. Actually, now, saying force is power isn't a strange expression for his logic of any Joe who hasn't seen any school in his life. Now, let me give another example to tell him what we technicans call a power rather than telling him what the power really is.. When you see a man keeping a big rock in his hands above his shoulders and stays so, what do we say? What a powerful man! Well, this was in very old days, centuries ago, in pre-engineering life. Today, correct expression is "strong man", not powerful man. To call him hercule or powerful man, we technics look at "how fast" he lifted the rock up above his shoulders, which means there is "time" in ranking. This is why today we divide quantities by time to call the output as power. So, power in old days was like a static concept while today it requires a dynamic to have a power. But, even at Newton's times, 5 century ago, we forget there is a hidden "time" even in static force like gravitational force, weight. People at Newton's time were understandable as they didn't know gravitational acceleration isn't constant actually. But, although we learn it in early school days, we forget our early assumptions, neglecting things like change in gravitational accelerations which is indeed small. But, forgetting this assumption make us lose our base, and errors in technique accumulate in further stages of educations and communication language gap between average Joe and engineers gets bigger and miscommunications happen a lot. But, engineers should be respected more, even more than pure mathematicans who try to pull engineers toward themselves and they open the gap more. Engineers are like middle-men, who are blamed or critisized more than others, so, because they are close to average Joe. Average Joe critisizes engineers not by telling things to him clearly. On the other end side, pure mathematican critisizes engineer for his low level of science, and them pure mathematicans even belittle them engineers, even physicans and applied mathematicans. Average Joe living in a "very real" life and pure mathematican Joe living in totally another world out of totally real life should have a meeting and lets see what these two lazies can do about what engineers couldn't.
    ! ... Well, it occurs to me that you might be able to explain the term G^2/Hz used in random vibration. Can you do it real? It would be useful to my mind.
    larry
    This side of 40
    JD2010, Kubota L3450/FEL w SK QC, L2550 w FEL
    Mahindra 7520 [Pinky] /FEL w Skid Steer QC/w Tilt Tatch & BH, BX1500 [Mighty Mouse]
    IH37 Baler, CCM165 Drum Mower, JD Rake
    JD 127 bushog, Flail, SK Tilt Tatch , KK tiller, Rhino rear blade, Post driver, post auger, chipper, pallet fork, Grapple/Loader Buddy, Homemade Splitter/DC Welder

  2. #142
    Elite Member
    Join Date
    Dec 2002
    Posts
    2,660
    Location
    Foster, RI
    Tractor
    Mahindra 3016

    Default Re: Does HP matter?

    You guys are insufferable I know this. It takes all kinds for what we do on this earth from those crazy ladies who run day care to the men who control our debris. I appreciate everyone and their varied brain builds. For anyone to look down anyone's nose whether it be a mathematician, a quantum scientist or a chimney sweep either doing so to each other or otherwise aren't taking full advantage and benefit of the world around them. Thank you for your input. Its been a combination of pleasure and teeth pulling.
    Last edited by arrow; 12-16-2012 at 04:20 PM.

  3. #143
    New Member
    Join Date
    Nov 2012
    Posts
    22
    Location
    House Springs,Mo.
    Tractor
    Kubota M7040

    Default Re: Does HP matter?

    More is always better than never enough go for something around 10 HP more than what you think you will need in the long run you will be glad you did !!!!

  4. #144
    Platinum Member
    Join Date
    Oct 2002
    Posts
    912
    Location
    TR
    Tractor
    MH744

    Default Re: Does HP matter?

    Quote Originally Posted by SPYDERLK View Post
    ! ... Well, it occurs to me that you might be able to explain the term G^2/Hz used in random vibration. Can you do it real? It would be useful to my mind.
    larry
    Larry, you are pulling my legs into the mud I been in before (my thesis was about chaos though not statistically or stochastically, but, from deterministic and analytic point of view.)

    Let me guess, you are an engineer and in electronics, who you have worked or been working in electronic filters too. Averaging experimental or real data and to try to simplify works of filters by trying to find some simpler analitical formulas to reduce freedom dimension in chaotic signals. Raw data is mathematically in discrete group. I was in other side, searching chaotic behaviours in deterministic, analytical, continuous groups which is more strange to even high experts of physicans and applied mathematicans. Anyway, I wasn't in stochastic deeply, but, will try to interpreate G^2/Hz (but, in a language with average Joes can understand without their running their minds which are not reserved for such things.)

    G^2: Lets not talk about this much as this is a stochastic quantity which won't be easy for anyone who is totally foreigner to stochastic quantities. Lets call it Root Mean Square of a quantity which physicans called it acceleration. (mathematicans call quantities without physical meanings while physicans try to name quantities by connecting them to some real, known, things. It is not acceleration (change in velocity) actually that common know. But, physicans prefer to use acceleration for any "change of change of a quantity" even if quantity isn't length, ft.. Square root of square of a quantity is for averaging reason as wave goes up (positive) and down (negative) sides of an axis, so to find absolute values. By averaging, and hence, grouping, actually, symmetries are searched in random vibrations so to simplify/reduce the freedom dimension of chaos or seem-to-be random motions. Pressumptions there such as lapping simple periodic waves over each others many times. Finding such simple symmetries or periodic waves in random waves will reduce dimensions of freedom and degree of randomness will reduce, so that with less effort (computation or measurement), data can be analysed. Anyway, lets stay with name "a stochastic quantity" about G. (I guess, the intention here is not questioning what G is, but, its dividing by frequency, Hz.)

    Frequency, that's, Hz. that's, "cycle per second." It is a quantity in the same group with RPM as both are 1/time.

    G, a stochastic quantity, per "cycle per time" is called somethings like "power" in stochastic field and you are asking this because it is confusing people as it is not "per time", but, "per cycle/time." As I said, it is due to Physicans who like to use "known" physical quantity names for somethings new quantites per somethings. In wave field, people prefer to use things per cycles such as energy per cycle, etc or even "per cycle per time" which is frequency so to simplify/reduce their dependent variables, so, to play with less number of equations.

    Ok, this is becoming an advanced topic for average Joes who are probably asking even what the wave is. (not belittleing anyone here, but, this question is like doing an advanced math) Who can explain what the wave is to a man who has lived in a cave or a small village for his whole life, without attending even elementary school? This seem-to-be easy question is actually a hard question even for high educated people. Since this is public, what I was trying to do in my posts above is to try to tell things in such a language that everybody in public can understand. (I'd like to explain what the wave, periodic wave, random wave, etc by using a simple wheel on a road, but, anyway, not here now as we are really going off-topic.)

  5. #145
    Veteran Member Jerry/MT's Avatar
    Join Date
    Feb 2008
    Posts
    1,989
    Location
    Western Montana
    Tractor
    New Holland TD95D, Ford 4610 & Ferguson TO-30

    Default Re: Does HP matter?

    Quote Originally Posted by nomad View Post
    Larry, you are pulling my legs into the mud I been in before (my thesis was about chaos though not statistically or stochastically, but, from deterministic and analytic point of view.)

    Let me guess, you are an engineer and in electronics, who you have worked or been working in electronic filters too. Averaging experimental or real data and to try to simplify works of filters by trying to find some simpler analitical formulas to reduce freedom dimension in chaotic signals. Raw data is mathematically in discrete group. I was in other side, searching chaotic behaviours in deterministic, analytical, continuous groups which is more strange to even high experts of physicans and applied mathematicans. Anyway, I wasn't in stochastic deeply, but, will try to interpreate G^2/Hz (but, in a language with average Joes can understand without their running their minds which are not reserved for such things.)

    G^2: Lets not talk about this much as this is a stochastic quantity which won't be easy for anyone who is totally foreigner to stochastic quantities. Lets call it Root Mean Square of a quantity which physicans called it acceleration. (mathematicans call quantities without physical meanings while physicans try to name quantities by connecting them to some real, known, things. It is not acceleration (change in velocity) actually that common know. But, physicans prefer to use acceleration for any "change of change of a quantity" even if quantity isn't length, ft.. Square root of square of a quantity is for averaging reason as wave goes up (positive) and down (negative) sides of an axis, so to find absolute values. By averaging, and hence, grouping, actually, symmetries are searched in random vibrations so to simplify/reduce the freedom dimension of chaos or seem-to-be random motions. Pressumptions there such as lapping simple periodic waves over each others many times. Finding such simple symmetries or periodic waves in random waves will reduce dimensions of freedom and degree of randomness will reduce, so that with less effort (computation or measurement), data can be analysed. Anyway, lets stay with name "a stochastic quantity" about G. (I guess, the intention here is not questioning what G is, but, its dividing by frequency, Hz.)

    Frequency, that's, Hz. that's, "cycle per second." It is a quantity in the same group with RPM as both are 1/time.


    G, a stochastic quantity, per "cycle per time" is called somethings like "power" in stochastic field and you are asking this because it is confusing people as it is not "per time", but, "per cycle/time." As I said, it is due to Physicans who like to use "known" physical quantity names for somethings new quantites per somethings. In wave field, people prefer to use things per cycles such as energy per cycle, etc or even "per cycle per time" which is frequency so to simplify/reduce their dependent variables, so, to play with less number of equations.

    Ok, this is becoming an advanced topic for average Joes who are probably asking even what the wave is. (not belittleing anyone here, but, this question is like doing an advanced math) Who can explain what the wave is to a man who has lived in a cave or a small village for his whole life, without attending even elementary school? This seem-to-be easy question is actually a hard question even for high educated people. Since this is public, what I was trying to do in my posts above is to try to tell things in such a language that everybody in public can understand. (I'd like to explain what the wave, periodic wave, random wave, etc by using a simple wheel on a road, but, anyway, not here now as we are really going off-topic.)


    Power spectral density (PSD) analyzers generallly express the ordinate as Energy/hz with frequency as the absissa, as i recalll (but my recollection is to good! grin).

  6. #146
    Platinum Member
    Join Date
    Oct 2002
    Posts
    912
    Location
    TR
    Tractor
    MH744

    Default Re: Does HP matter?

    Returning back to original topic "does hp matters really",

    HP you are given (in specs section of catalogue) usually is about the engine, not the pto.
    Whether it is car or tractor or whatever, there is the gear chain system (gearbox) between engine and work-maker end (tyres or pto.). Gearbox decides how much of HP will be converted to Torque and how much to Speed. In cars, most of HP is converted to Speed while mostly to Torque in work-maker vehicles like tractors. (remember HP is a multiplication of Torque and Speed. So, HP is constant for an engine while its torque and speed can be changed by gear systems.) If Torques of 2 vehicles with different HPs are SAME, then, bigger HP vehicle will do the same work faster, but, won't be able to do heavier work, that's it.
    Last edited by nomad; 12-19-2012 at 08:04 AM.

  7. #147
    Super Member LD1's Avatar
    Join Date
    Apr 2008
    Posts
    9,988
    Location
    Central Ohio
    Tractor
    Kubota l3400

    Default Re: Does HP matter?

    Quote Originally Posted by nomad View Post
    If Torques of 2 vehicles with different HPs are SAME, then, bigger HP vehicle will do the same work faster, but, won't be able to do heavier work, that's it.
    That is exactally what I have been preaching all along.
    ".........there is only one way to find out."
    "Ok, hold my beer and watch this.........."


    Ford 5500 Backhoe
    Kubota L3400GST W/LA463 FEL
    2005 Dodge 3500 4x4 Diesel
    8N Rebuilt and restored
    Bushhog 306
    3 Homemade wood hauling trailers
    Dolmar 6400 84cc ported
    Sachs-Dolmar 120SI Ported
    (4) Sachs-Dolmar 116SI Ported
    Dolmar PS540
    Sachs-Dolmar 115i
    Sachs-Dolmar 117
    Sachs-Dolmar 112

  8. #148
    R.I.P.
    Join Date
    Dec 2008
    Posts
    5,883
    Location
    North Carolina
    Tractor
    Kubota BX2200

    Default Re: Does HP matter?

    Quote Originally Posted by LD1 View Post
    That is exactally what I have been preaching all along.
    If we are talking about torque and HP available at the wheel, I agree. If we are talking at the engine, I must know the gearing available. If the gearing is identical, I agree so long as "won't be able to do heavier work" means "won't be able to do heavier work than the other vehicle."
    Which is bigger?: a) $100 per month since the Big Bang or b) the US National Debt.

  9. #149
    Platinum Member
    Join Date
    Oct 2002
    Posts
    912
    Location
    TR
    Tractor
    MH744

    Default Re: Does HP matter?

    I got an email asking this (I believe there are some other people too who are asking same things.)

    Someone wrote:
    ".... If Torques of 2 vehicles with different HPs are SAME, then, bigger HP vehicle will do the same work faster, but, won't be able to do heavier work, that's it.

    Torques are same in given portion. HPs are different in given portion. The Bigger HP vehicle doing the work faster is implied by the HP being larger with same torque. But how is it known this vehicle cannot do heavier work? It was given equal torque and higher power..."

    ---------

    Maybe, because of my English (my 2nd language) - maybe, because of technical issues (2nd language of people foreigner to technical terms) - people might be confused about my sentence above and may say "how comes! bigger power must do heavier work! and Nomad, you are wrong.."

    Let me make it clear.

    HP is power of engine. You divide it to portions: Torque work and Speed work. Remember again Power = Torque x Speed...

    Torque does the work at pto, that's, a portion of engine power is used at pto as torque is to make the work there at pto. So, through gears in gearbox, lets say 90% of engine power is used at pto, 5% is used to carry the weight of tractor and 5% is reserved for Speed of tractor. (figures i say here are just arbitrary.)

    Lets say we have 2 tractors: one has 100 hp engine and the other has 110 hp engine.. But, with SAME torques at their pto's.. (this was the question in original post.) Lets say 90 hp of each of these tractors are reserved for their pto torques. Then, tractor with 100 hp engine will use 10 hp for speed while tractor with 110 hp can use 20 hp for speed - and this means, 110 hp tractor can run faster while doing the same MAXIMUM amount of work at its pto.. Pto torque is given as rated or maximum pto torque. So, since their torques, peak / rated / maximum torques, are same, even higher HP engine tractor won't make heavier work - but, tractor movement will be faster. However, if you change gearbox of higher hp tractor, then, of course, you can have bigger torque at bigger hp tractor, but, then its faster speed will reduce.

    This is most important formula for the relation between power and torque:

    Power (HP) = Torque (lf.ft) x Speed (Rpm) x Some Constant

    (forget about this "some constant", not so important, changes depending on the units (second, hour, etc) you use..) Play with this formula, by keeping torque as constant or speed as constant, etc. my words in paragraph above will be clear then.

  10. #150
    Platinum Member
    Join Date
    Oct 2002
    Posts
    912
    Location
    TR
    Tractor
    MH744

    Default Re: Does HP matter?

    Quote Originally Posted by EE_Bota View Post
    If we are talking about torque and HP available at the wheel, I agree. If we are talking at the engine, I must know the gearing available. If the gearing is identical, I agree so long as "won't be able to do heavier work" means "won't be able to do heavier work than the other vehicle."
    Powers, HPs, in question are engine powers. Torques (same) mentioned here in first post is PTO torques. Therefore, gearing is NOT identical, gear ratios are different, hence, torques of different HPs are same at ptos. So, output power hp at pto is same since both pto have same rpm, 540, and torques are same, though their engine hps are different.

Page 15 of 17 FirstFirst ... 5121314151617 LastLast

Similar Threads

  1. Will 5 hp more matter ?
    By castiman in forum John Deere Buying/Pricing
    Replies: 21
    Last Post: 02-19-2011, 12:31 PM
  2. It was only a matter of time
    By Diamondpilot in forum Trailers & Transportation
    Replies: 41
    Last Post: 08-04-2008, 05:12 AM
  3. Does size matter?
    By EastTractor in forum Owning/Operating
    Replies: 6
    Last Post: 06-05-2007, 05:33 PM
  4. Does size really matter?
    By Zoombah in forum Attachments
    Replies: 32
    Last Post: 06-11-2006, 11:16 PM
  5. It was only a matter of time.
    By Hillbilly in forum Related Topics
    Replies: 12
    Last Post: 12-05-2001, 04:53 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2014 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.