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Old 03-18-2005, 05:02 AM   #31
windsonian
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WORK is done when a force (or torque) moves an object through a distance (ie Fxd)
TORQUE is a twisting force applied by a linear force acting at a distance (radius) from the pivot point (ie Fxd)

So the equations, and hence the units (lb-ft or whatever you want to use), look the same too - eventhough the two distances being multiplied are different.

Basic example showing differences:
Torque a nut with a 0.5m long socket wrench (long I know, but easier for calcs)
Apply 10 Newtons (approx 2.25lb I think) of force at the end of the wrench to tighten the nut.
With this much force, the nut travels 1 revolution before stopping (more force would tighten it more, but we're stopping at 10N)

The TORQUE applied to the nut is 10N x 0.5m = 5Nm (approx 3.7lb-ft I think)

To rotate one revolution, the end of the socket wrench has travelled 2 x pi x r = 2 x pi x 0.5 = 3.14m (approx 10.5 ft I think)

Therefore, the WORK done to move the force through this distance is 10N x 3.14m = 31.4 Nm (approx 23.2 lb-ft I think)

So change your lb.ft to ft.lb or whatever if you want .... but as you can see, even though the units are similar, WORK and TORQUE are not the same.
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Old 03-18-2005, 04:31 PM   #32
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Quote:
Originally Posted by vwhobo
Thank you. When torquing a bolt you are only doing work until the bolt stops, i.e. when the torque wrench clicks. At that point you are only applying force. It is the potential for work, hence the terminology lb-ft. Remember "TORQUE is defined as a FORCE around a given point, applied at a RADIUS from that point. Have you got it now?


Well, at that point you're finished. It's out of the topic. What happens after you've finished torquing a bolt is out of the scope of our discussion. What you're saying would be true if you say, had a bolt torqued to 100 ft-lb, took your trusty torque wrench and applied 20 ft-lb of torque. Well, you just applied 20 lb-ft of torque because you didnt move the torque wrench.


From that link you gave...
"WORK is defined as a FORCE operating through a DISTANCE"

When you torque a bolt, you are doing work. That is the ft-lb. I do see your point and it is a valid one. It brings gray to the matter. All the more reason to believe what tbaxleyjr said in (I think) another thread. BUT, since my torque wrenches and all my books give torque figures in foot-pounds, that's how I'm going to refer to it.
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Old 03-18-2005, 04:34 PM   #33
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Quote:
Originally Posted by windsonian
So change your lb.ft to ft.lb or whatever if you want .... but as you can see, even though the units are similar, WORK and TORQUE are not the same.


How can you say work and torque are not the same (which is correct) and then say lb-ft and ft-lb are "similar"? Like I said before... work is the ft-lb and torque is the lb-ft. Therefor, lb-ft and ft-lb are just as different as work and torque is.
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Old 03-18-2005, 04:37 PM   #34
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Did Anyone Ever Answer The Guy's Question??? I Thuoght This Forum Was To Help Each Other
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Old 03-18-2005, 10:43 PM   #35
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Originally Posted by DONHUD
Did Anyone Ever Answer The Guy's Question??? I Thuoght This Forum Was To Help Each Other
bet thats the end
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Old 03-19-2005, 12:23 AM   #36
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Originally Posted by DONHUD
Did Anyone Ever Answer The Guy's Question??? I Thuoght This Forum Was To Help Each Other


I believe I did.
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Old 03-19-2005, 05:44 AM   #37
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wow all this.

i really do not care for proper spellig punktuation etc.this is not a spelling or english test.HOWEVER ,IT IS FT/LB.torque is a rotational force.work can be a linear measurement.or non linear for that matter,such as torque produced by an accelerating engine.the energy that remains AFTER THE TORQUE IS APPLIED,IS ACTUALLY KINETIC ENERGY.AS FAR AS CHECKING THE BOLTS ON AN AIRCRAFT,good point ,all pre flight checks say check the engine oil,etc under the cowl.did you know that the only people allowed to service their own aircraft,other than an AME are owners,if they have built their own airplane.
speaking of if we ever helped that poor kid out,if he puts the manufacturer,and displacement of the engine,i or any of us can look it up,and he CAN USE A TORQUE WRENCH AND TORQUE IT IN THE SEQUENCE,USING THE EVER SO POPULAR FOOT/LBS. speaking of what is a foot lb? is it the energy required to move one pound 1 foot in one second,or 1 minute? does torque change at say 50000 feet? we can get into that too.hey if you torque something to 100 ft pounds,and then heat it up yo 350c
does the torque energy ,stored as kinetic (in a spring say) change?.
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Old 03-19-2005, 07:38 AM   #38
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Old 03-19-2005, 05:27 PM   #39
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Quote:
Originally Posted by DodgeRida67
Well, at that point you're finished. It's out of the topic. What happens after you've finished torquing a bolt is out of the scope of our discussion. What you're saying would be true if you say, had a bolt torqued to 100 ft-lb, took your trusty torque wrench and applied 20 ft-lb of torque. Well, you just applied 20 lb-ft of torque because you didnt move the torque wrench.


From that link you gave...
"WORK is defined as a FORCE operating through a DISTANCE"

When you torque a bolt, you are doing work. That is the ft-lb. I do see your point and it is a valid one. It brings gray to the matter. All the more reason to believe what tbaxleyjr said in (I think) another thread. BUT, since my torque wrenches and all my books give torque figures in foot-pounds, that's how I'm going to refer to it.
No, but you're getting there. Let me make this just as simple for you as I possibly can using an imaginary engine.

You are assembling the imaginary engine and are to the point of installing the head that is attached by bolts that torque to 50 lb-ft with no intermediate steps. You drop on the head and then drop in the bolts. Let's say for simplicity that the head bolts are 1/2"-20 in size and the bolt head flange is standing 2" above the head surface when you first catch a thread, in other words they thread into the block 2" or 40 threads. With me so far?

Of course because you're a meticulous engine builder the threads in both the block and on the bolts are in perfect condition and properly lubricated. For the first 20 or so threads (1") you simply spin them in with with your fingers. At this time you are doing work, not much, but work non the less. At this point the friction of the threading action (formally know as run-in torque) makes you reach for your speed handle to keep threading them in. For the next 18 or so turns (slightly less than 1") you are still doing work, even more than before. Notice that as long as the bolts are turning you are in fact doing work. Remember, "Work is force operating through a distance".

Now you have the bolts turned in and making contact with the head, good and snug. Time for the final torque. You pull your trusty torque wrench (just wrench from now on for typing ease) out of it's padded case, check the calibration date, look to make sure when it was last stored it was adjusted to the lowest setting, set it to 50 lb-ft and then do 5 to 8 test pulls to ensure the internal mechanism is properly seated before being used on a critical fastener. If you're not doing these things EVERY TIME don't pretend to tell me how to use a wrench and also be aware that skipping these steps makes using said wrench eye candy, but still better than not using one at all. And just as a side note I notice you displayed a Craftsman wrench earlier. They're not a bad tool but are notoriously inaccurate due to poor packaging, rough handling and improper use and maintenance (see above). Back to the engine.

Time to torque the first bolt (I'll only explain it once as the process is the same for all of them). You have the wrench set to 50 lb-ft. You have the appropriate socket and extension attached. You place it on the bolt and begin to move. Even though the wrench is adjusted to 50 lb-ft you are not doing that much work but rather somewhat less. How do I know that? Because if you had reached 50 lb-ft the wrench would have clicked. You turn the wrench 90 degrees and it still pulls easily. You go for another 90 degrees and while you feel it snugging down the bolt it's still fairly easy... and still somewhat less than 50 lb-ft. You go for another 90 degrees and it's starting to tighten up. One more turn should do it. You go for one more 90 and it's almost there. 46... 47... 48... 49... All this time the wrench and the fastener are moving. As long as they are moving you are doing work "Work is force operating through a distance". Finally the moment you've been waiting for, CLICK. You have now reached 50 lb-ft. Are you still turning the wrench? You shouldn't be. Is the fastener still moving? Hope not. Why? Because you are applying a force of 50 lb-ft but what you are not doing is any work... You are only applying force.

I really don't understand why this concept is so hard to comprehend. It's quite simple really and painfully obvious to boot. More importantly I can only think of one other way to explain it. I honestly hope that you will try to open your mind, see the light and learn. If you can't do that at your age I can just imagine how closed minded you'll be at my age. Have a nice day.


.



Final note. I don't really care if you like me. I certainly don't care if you call me an asshole. But I don't appreciate you spewing in various posts that I never do anything to help anyone on this forum. If you're honest about it you know I provide at least as much useful help as anyone else and far more than most. And like it or not YOU'VE continually benefitted from my knowledge, experience and help as well.
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Last edited by vwhobo : 03-19-2005 at 05:34 PM.
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Old 03-19-2005, 05:27 PM   #40
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Quote:
Originally Posted by DONHUD
Did Anyone Ever Answer The Guy's Question??? I Thuoght This Forum Was To Help Each Other
Why don't YOU answer his question?
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Thanks for the pic, jedimario.

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Old 03-19-2005, 05:54 PM   #41
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Quote:
Originally Posted by the lobster
i really do not care for proper spellig punktuation etc.this is not a spelling or english test.HOWEVER ,IT IS FT/LB.torque is a rotational force.work can be a linear measurement.or non linear for that matter,such as torque produced by an accelerating engine.the energy that remains AFTER THE TORQUE IS APPLIED,IS ACTUALLY KINETIC ENERGY.AS FAR AS CHECKING THE BOLTS ON AN AIRCRAFT,good point ,all pre flight checks say check the engine oil,etc under the cowl.did you know that the only people allowed to service their own aircraft,other than an AME are owners,if they have built their own airplane.
speaking of if we ever helped that poor kid out,if he puts the manufacturer,and displacement of the engine,i or any of us can look it up,and he CAN USE A TORQUE WRENCH AND TORQUE IT IN THE SEQUENCE,USING THE EVER SO POPULAR FOOT/LBS. speaking of what is a foot lb? is it the energy required to move one pound 1 foot in one second,or 1 minute? does torque change at say 50000 feet? we can get into that too.hey if you torque something to 100 ft pounds,and then heat it up yo 350c
does the torque energy ,stored as kinetic (in a spring say) change?.
You sir are a verifiable waste of oxygen... and bandwidth. Everyone makes the occasional and understandable misspelling, what you do is pure laziness or stupidity. Maybe both.

Since you asked, yes, I know do who can and cannot work on aircraft. I have a ticket that says I can... or didn't your read that part of the post. Maybe you just don't know what an A&P certified mechanic is because the only aircraft you've ever flown came out of a Cracker Jacks box.

Finally... let's look at the second sentence (if you want to call it that) of your post. I have read that, or something very close to it, on this forum perhaps a thousand times. Every single time it ends up being some twelve year old trying to pass himself off as a racing driver, millionaire, international playboy and now a pilot. If I'm correct, and I think I'm close, that would back-up my idea in the second paragraph. Think about it, I have.
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Old 03-19-2005, 06:39 PM   #42
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Quote:
Originally Posted by vwhobo
Why don't YOU answer his question?
HIS QUESTION WAS IF THERE WAS A WEB SITE FOR THE SPECS. I KNOW OF NONE, BUT WOULD BE INTERESTED IF ONE EXISTS. I HAS BEEN FUN READING YOUR EXPLAINATIONS, BUT REALLY DID NOT HELP WITH THE GUY'S QUESTION. MY HEAD IS SPINNING FROM ALL THIS INFO, GUESS I WOULD TELL THE GUY TO GO TO PARTS STORE AND ASK TO LOOK IT UP IN A MANUAL, THEY HAVE ALWAYS BEEN HELPFUL TO ME IN THIS WAY.
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Old 03-19-2005, 07:48 PM   #43
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Quote:
Originally Posted by DONHUD
HIS QUESTION WAS IF THERE WAS A WEB SITE FOR THE SPECS. I KNOW OF NONE, BUT WOULD BE INTERESTED IF ONE EXISTS. I HAS BEEN FUN READING YOUR EXPLAINATIONS, BUT REALLY DID NOT HELP WITH THE GUY'S QUESTION. MY HEAD IS SPINNING FROM ALL THIS INFO, GUESS I WOULD TELL THE GUY TO GO TO PARTS STORE AND ASK TO LOOK IT UP IN A MANUAL, THEY HAVE ALWAYS BEEN HELPFUL TO ME IN THIS WAY.
I don't know what is making my head hurt worse right now, the concussion I gave myself this morning or the fact that you are yelling at me for no apparent reason. Find the "Caps Lock" button on your keyboard and USE IT!

I am fully aware of what the original question that started out this thread is/was. As you are also apparently aware, why did it take you TWO posts to acknowledge his question and then not answer it? You are the pot calling the kettle black, bitching about nobody else doing what you didn't do either.

Why haven't I attempted to answer his question? Because it's obvious he didn't take the time to read this;

http://www.car-forums.com/talk/showthread.php?t=2200

If he did read it he certainly didn't bother to follow the extremely simple instructions. On the other hand I just looked at your short history of posts on this forum and you don't seem to get it either. The more you're willing to help yourself, the more we're able to help you.

In summary, if you want it done better than go ahead and do it better. Just don't whine because someone else didn't do it for you. And that parts stores are there to SELL manuals, not let cheap bastards read them for free. That's what libraries are for.
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Old 03-20-2005, 01:52 AM   #44
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Quote:
Originally Posted by vwhobo
No, but you're getting there. Let me make this just as simple for you as I possibly can using an imaginary engine.

You are assembling the imaginary engine and are to the point of installing the head that is attached by bolts that torque to 50 lb-ft with no intermediate steps. You drop on the head and then drop in the bolts. Let's say for simplicity that the head bolts are 1/2"-20 in size and the bolt head flange is standing 2" above the head surface when you first catch a thread, in other words they thread into the block 2" or 40 threads. With me so far?

Of course because you're a meticulous engine builder the threads in both the block and on the bolts are in perfect condition and properly lubricated. For the first 20 or so threads (1") you simply spin them in with with your fingers. At this time you are doing work, not much, but work non the less. At this point the friction of the threading action (formally know as run-in torque) makes you reach for your speed handle to keep threading them in. For the next 18 or so turns (slightly less than 1") you are still doing work, even more than before. Notice that as long as the bolts are turning you are in fact doing work. Remember, "Work is force operating through a distance".

Now you have the bolts turned in and making contact with the head, good and snug. Time for the final torque. You pull your trusty torque wrench (just wrench from now on for typing ease) out of it's padded case, check the calibration date, look to make sure when it was last stored it was adjusted to the lowest setting, set it to 50 lb-ft and then do 5 to 8 test pulls to ensure the internal mechanism is properly seated before being used on a critical fastener. If you're not doing these things EVERY TIME don't pretend to tell me how to use a wrench and also be aware that skipping these steps makes using said wrench eye candy, but still better than not using one at all. And just as a side note I notice you displayed a Craftsman wrench earlier. They're not a bad tool but are notoriously inaccurate due to poor packaging, rough handling and improper use and maintenance (see above). Back to the engine.

Time to torque the first bolt (I'll only explain it once as the process is the same for all of them). You have the wrench set to 50 lb-ft. You have the appropriate socket and extension attached. You place it on the bolt and begin to move. Even though the wrench is adjusted to 50 lb-ft you are not doing that much work but rather somewhat less. How do I know that? Because if you had reached 50 lb-ft the wrench would have clicked. You turn the wrench 90 degrees and it still pulls easily. You go for another 90 degrees and while you feel it snugging down the bolt it's still fairly easy... and still somewhat less than 50 lb-ft. You go for another 90 degrees and it's starting to tighten up. One more turn should do it. You go for one more 90 and it's almost there. 46... 47... 48... 49... All this time the wrench and the fastener are moving. As long as they are moving you are doing work "Work is force operating through a distance". Finally the moment you've been waiting for, CLICK. You have now reached 50 lb-ft. Are you still turning the wrench? You shouldn't be. Is the fastener still moving? Hope not. Why? Because you are applying a force of 50 lb-ft but what you are not doing is any work... You are only applying force.

I really don't understand why this concept is so hard to comprehend. It's quite simple really and painfully obvious to boot. More importantly I can only think of one other way to explain it. I honestly hope that you will try to open your mind, see the light and learn. If you can't do that at your age I can just imagine how closed minded you'll be at my age. Have a nice day.


.



Final note. I don't really care if you like me. I certainly don't care if you call me an asshole. But I don't appreciate you spewing in various posts that I never do anything to help anyone on this forum. If you're honest about it you know I provide at least as much useful help as anyone else and far more than most. And like it or not YOU'VE continually benefitted from my knowledge, experience and help as well.


I knew that was your thoughts on it... I addressed that in my last post. BUT, while that is a good point, like I said before, since I've always seen torque figures given in ft-lbs it's just how I'm going to refer to it.


On your final note, never said I didn't like you. I like the way you operate but... some of the things you do I don't like. Yes, of course you help people around here. Yes, I have benefitted from you.
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Old 03-20-2005, 05:16 AM   #45
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well well

I love listening to all you people rave about how smart you are and how much you all know.

vwhobo, just let them torque their valve covers in a scale of feet per every one pounds. It will be fun, i love buying decent cars cheap because some nit-wit royally ****ed it up.

And on a last note, did you say "Since you asked, yes, I know do who can and cannot work on aircraft. I have a ticket that says I can... or didn't your read that part of the post.", (which is perhaps one of the most f*c*ed up sentences on this entire forum) on purpose, as some sort of ironical joke? Or are you really that hypocritical?

As for this dude's question, look it up for christ's sake, do you see what you started hear? It's like the friggen war in Iraq.
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