Torque Amp

[MinnesotaDave]

After some pondering, here is where I'm at. (my thoughts are for a torque wrench that is free to move normally)

The goal as the bolt/nut reaches desired torque is to create the same static system that would normally occur without the socket extension.

The hand on the torque wrench head is just to counter the sideways force that would tip the wrench out of the crows foot.

Ideally, this would allow a person to continue to swing the entire system around the central pivot (nut/bolt).

If a person balances these forces, only a minor error should occur.

However, if a person ratchets the torque wrench so the the crows foot comes out of parallel with the centerline of the wrench, then actual applied torque will change.

[William McCormick]

After some pondering, here is where I'm at. (my thoughts are for a torque wrench that is free to move normally)

The goal as the bolt/nut reaches desired torque is to create the same static system that would normally occur without the socket extension.

The hand on the torque wrench head is just to counter the sideways force that would tip the wrench out of the crows foot.

Ideally, this would allow a person to continue to swing the entire system around the central pivot (nut/bolt).

If a person balances these forces, only a minor error should occur.

However, if a person ratchets the torque wrench so the the crows foot comes out of parallel with the centerline of the wrench, then actual applied torque will change.

I was trying that formula on other scenarios and it seems to work. I noted that the error is not always the torque when I tried it on other length crow's feet and different length bars and torques but the formula checks out, I almost cannot wait to prove it when my wrenches come. I also ordered a hanging scale to check out the wrenches and the formula.


Sincerely,

William McCormick

[William McCormick]

After some pondering, here is where I'm at. (my thoughts are for a torque wrench that is free to move normally)

The goal as the bolt/nut reaches desired torque is to create the same static system that would normally occur without the socket extension.

The hand on the torque wrench head is just to counter the sideways force that would tip the wrench out of the crows foot.

Ideally, this would allow a person to continue to swing the entire system around the central pivot (nut/bolt).

If a person balances these forces, only a minor error should occur.

However, if a person ratchets the torque wrench so the the crows foot comes out of parallel with the centerline of the wrench, then actual applied torque will change.

I believe that rotational shaft torque is shaft torque. Once you add the typical socket extension between the crow's foot and any wrench, you are only dealing with rotational torque. And I am sure that if you use torque alone to create 556 foot-pounds of force on the bolt we wish to tighten with a crow's foot, you would need 556 foot-pounds to do it. So the original poster's situation needs the torque wrench to be inline and parallel with the crow's foot to gain lever force. The problem with the formulas from engineering sites is that they only calculate the lever force, they make no consideration or provision for the torque that is created by the torque wrench that is being loaded and applying torque as well as lever force. It is interesting I would have probably never come across that ratio if the 132 was not also the error. Because in other formulas the torque does not work out to be the error. But the formula does self-check itself, assuming that the torque created during the lever loading has to be counted in addition to the lever force created by your hand.

Sincerely,

William McCormick

[William McCormick]

Here is the same thing but instead of 132 that we have been throwing around I used the actual number which is 132.380952380952381 now everything balances out.

If you take 556 and add 132.380952380952381 to it you get 688.380952380952381 my proposed actual torque on the bolt. if you then divide 556 by 688.380952380952381 you get 0.8076923076923077 that is the ratio I claim the formula is off by. Now if you take 556 divided by 5.25 you get 105.9047619047619048 the amount of tangential force in pounds you need on a single lever 5.25 feet long. If you take 105.9047619047619048 pounds and multiply it by 0.8076923076923077 you get 85.538461538461538 pounds of force needed from your hand on the 1.25-foot long torque wrench attached inline and parallel to the 4-foot long crow's foot. If you then multiply 85.538461538461538 by 1.25 you get 106.9230769230769231 foot-pounds of torque reading on the torque wrench and applied to the crow's foot.

To check that you multiply 85.538461538461538 times 5.25 and you get 449.076923076923075 pounds of pure lever force. Then you add 449.076923076923075 plus 106.9230769230769231 and you get 556 foot-pounds of torque applied to the bolt.

But again I will check this out easily with the two wrenches I have coming. I think they get here Thursday.

I did it with another scenario and because there is a lot going on it is a bit mind-boggling but it does seem to work. But the formula from the engineering sites say if you have a 12" crow's foot and a two-foot torque wrench and you want to achieve 100 foot-pounds of force that you need 66.66666666666666666 pounds of torque on the torque wrench indicator. They take the 100 ft. lbs. desired and divide it by the overall length of the torque wrench 2 feet long plus the crow's foot 1 feet and come up with 33.3333333333333 pounds of tangential force on the torque wrench handle. Then they multiply the force on the handle of the torque wrench by the length of the torque wrench handle and come up with 66.66666666666666 pounds of torque needed to achieve 33.333333333333333 pounds of tangential force on the torque wrench. The problem of course is they are calculating purely the lever force so they end up with 166.66666666666666 ft. lbs. of torque on the bolt not 100 ft. lbs. Because a crows foot is a one-to-one torque device. If you supply it with 100 pounds of rotational force it will deliver 100 foot-pounds of torque.

So my formula just takes the 100/166.66666666666666666 and converts it to a ratio of 0.6 it then multiplies 33.3333333333333333 by 0.6 and comes up with 20 pounds of tangential force needed on the torque wrench handle. If you multiply twenty by the length of the two-foot torque wrench you get 40 pounds of torque needed on the torque wrench indicator. The twenty pounds of hand force on the torque wrench delivers 60 ft pounds of torque through the lever action of the three-foot lever and when you add the 40 pounds of torque being applied by the torque wrench to the crow's foot you get 100-foot pounds of torque to the edited: Bolt.


Sincerely,

William McCormick

[William McCormick]

I think what I meant to say about the 132 foot-pound error is that if I had not done so much calculating on that original formula with the 132 as a value I would not have recognized what was happening. Because there are several ratios present in that formula. In one way the engineering formula is always wrong by the amount of torque they calculate in my opinion. But the ratio of change of torque is different from scenario to scenario.

Sincerely,

William McCormick

[William McCormick]

We used to do this stuff in school until you wanted to hang up in the back of the class. But one teacher kept at it for a while and one day we were kind of sure that the formula lacked the torque value. But the bell rang and that was the end of it. This was like sixth grade or something though, I had never used a crow's foot with a socket extension to see the zanny movement. As soon as I saw it I knew something was up there. But life is so zanny you put off stuff like this.

Sincerley,

William McCormick

[MinnesotaDave]

You're rambling too much to track what you want to prove or disprove.

Just a personal opinion, being brief and concise is very helpful to this type of dialogue.

[William McCormick]

You're rambling too much to track what you want to prove or disprove.

Just a personal opinion, being brief and concise is very helpful to this type of dialogue.

Fishing for input, sharing some observations. I do not have terminology for things yet nor do I have them in a proper perspective so I am practicing talking about it to try to develop better communication it is a tricky subject to relay information about. As soon as I post something I see the error in the way I said something, even though I read it like ninety times. Also, not everyone is following along in a 123 manner so I am trying to include a complete picture that can lead to errors. Just waiting on the wrenches but the more I look at it the more I believe I can find enough generally understood information about it to prove it without the torque wrenches. But the torque wrenches will determine it for me.

Do you concur that the crow's foot takes pure torque and transfers that torque to the bolt? And if so would you also not have to concur that the formula used in the engineering calculators is not calculating that torque force.

Sincerely,

William McCormick

[William McCormick]

After some pondering, here is where I'm at. (my thoughts are for a torque wrench that is free to move normally)

The goal as the bolt/nut reaches desired torque is to create the same static system that would normally occur without the socket extension.

The hand on the torque wrench head is just to counter the sideways force that would tip the wrench out of the crows foot.

Ideally, this would allow a person to continue to swing the entire system around the central pivot (nut/bolt).

If a person balances these forces, only a minor error should occur.

However, if a person ratchets the torque wrench so the the crows foot comes out of parallel with the centerline of the wrench, then actual applied torque will change.

I think you said it there Dave. The hand on the torque wrench that is powering a socket extension that is driving the crow's foot, is taking away the lever force that would be present if the torque wrench was inline and parallel to the crow's foot. And if we measure the torque applied with the socket extension limiting the forces to rotational forces we will find it is a one-to-one ratio of torque input to torque output. We need the lever force to reach those levels of torque to the bolt because we do not have a torque wrench that can deliver 556 foot-pounds of torque handy. But as we build lever force we also create rotational torque on the crow's foot that would cause us to reach the 556 ft. lbs of torque applied to the bolt before we get to the projected force needed by the lever force alone projected by the engineer's formula and calculator.

Sincerely,

William McCormick

[William McCormick]

When I do mini splits I use two rubber isolation bushings one below and one above the mounting brackets of the ceiling cassets. I reach up through a rather small cutout and tighten and adjust the nuts on the 3/8" mounting rods using a crow's foot that is on a 12" socket extension bar, that I turn from below the ceiling with a ratchet wrench. To do one or two ceiling cassets it can take an hour or more just to set them properly many I have seen were not set well. So I get to see this a lot. The motion is so weird, you just need to maintain torque and the nut turns, you do not actually turn the ratchet wrench it is just darned weird to see and the ratchet can be in any position and the difficulty to turn the nuts is the same because it is just rotational force being applied.

Sincerely,

William McCormick

[William McCormick]

removed poorly formated post

[William McCormick]

I shortened it up a little.

What can you do with that Dave. I don't speak fancy math.

Sincerely,

William McCormick

[MinnesotaDave]

I shortened it up a little.

What can you do with that Dave. I don't speak fancy math.

Sincerely,

William McCormick

That largely depends on why you have written them.

The handwritten proof I provided shows that the original formula is valid for the common system.

I wrote up a little math based on the formulas you provided, I'll think on them a bit before posting.

[William McCormick]

That largely depends on why you have written them.

The handwritten proof I provided shows that the original formula is valid for the common system.

I wrote up a little math based on the formulas you provided, I'll think on them a bit before posting.

As I mentioned the commonly used formula is not including the rotational torque generated by the break in the two objects that a single lever does not have. The boxed formula only measures it as a single object lever creating a single lever torque and then gives you the torque setting on the wrench to give you what the torque wrench would have to read in order to create the force on the torque wrench handle. The actual torque created will be whatever the lever force will create plus the error of the rotational torque not accounted for. The rotational torque is transferred through the crow's foot as one to one rotational force. We can easily check the boxed formula and find that it is not allowing for any rotational torque.

I just wanted to know if you could shorten up those formulae I created. My wrenches should come today and my scale. But I am pretty sure about this one. A single lever only gives you one point of torque creation. A two-piece shaft creates the same lever force which is converted to tangential force at the connection of the torque wrench and crows's-foot. The torque that was created much like winding a clock is converted to pure rotational force at the joint and is a one to one force that will be above and beyond the lever force, giving an incorrect reading.

Sincerely,

William McCormick

[MinnesotaDave]

Did some moving around for you.

Got rid of "Over Torque" because I don't like it.




btw, Lc is the length of the crows foot.



An example with numbers would seem to indicate your original assumptions are not accurate.

[William McCormick]

Did some moving around for you.

Got rid of "Over Torque" because I don't like it.




btw, Lc is the length of the crows foot.



An example with numbers would seem to indicate your original assumptions are not accurate.

Genius Dave! Together there is nothing we couldn't do.

Sincerely,

William McCormick

[William McCormick]

Genius Dave! Together there is nothing we couldn't do.

Sincerely,

William McCormick

You have to remember the boxed common formula is only calculating a single one piece lever, the amount of force needed on the handle or the break point between torque wrench and crow's foot, and then reverse engineering to get the torque reading on the torque wrench needed to create that force, but never adding in the rotational ft. lbs. created at the joint, before reaching the force necessary on the torque wrench handle. So you will be snapping some bolts unless you use a socket extension and the exact torque setting that you wish applied to the bolt. Or our new formula in an inline setup.

Sincerely,

William McCormick

[MinnesotaDave]

You have to remember the boxed common formula is only calculating a single one piece lever, the amount of force needed on the handle or the break point between torque wrench and crow's foot, and then reverse engineering to get the torque reading on the torque wrench needed to create that force, but never adding in the rotational ft. lbs. created at the joint, before reaching the force necessary on the torque wrench handle. So you will be snapping some bolts unless you use a socket extension and the exact torque setting that you wish applied to the bolt. Or our new formula in an inline setup.

Sincerely,

William McCormick

The "new formula" is not any good.

After running through it to make the equivalent functions, using numbers in the example shows it doesn't work.

I highly doubt that there will be so much error (wasted energy) that 325 ft.lbs., minus the error, is actually valid.

[William McCormick]

The "new formula" is not any good.

After running through it to make the equivalent functions, using numbers in the example shows it doesn't work.

I highly doubt that there will be so much error (wasted energy) that 325 ft.lbs., minus the error, is actually valid.

I ran the numbers through our new formula and something did not come out right I think. But I am still checking.

Then I ran them through this thing and it seems ok but it does not look organized pretty or easy.



The numbers you put through our new formula, I put through the old formula and it came out and checked out.

I multiplied 150 by (18/21) and got 128.571428571428571 what the standard formula outputs for torque. I then multiplied 128.571428571428571 by (150 / (150 + 128.571428571428571)) which equals 69.230769230769231 the TS or torque wrench setting.

To check" if you take 69.230769230769231 and divide it by 1.5 the torque wrench length you get 46.153846153846154 pounds of tangential force on the torque handle, if you multiply that by the length of the whole lever 1.75 feet you get 80.769230769230769 pounds of foot torque created to the nut, then if you add that to 69.230769230769231 the TS or Torque Wrench Setting you get 150




Sincerely,

William McCormick

[William McCormick]

The new wrenches are here the new wrenches are here! And the new scale is here!




I didn't expect them till tomorrow.

Sincerely,

William McCormick

[William McCormick]

Did some moving around for you.

Got rid of "Over Torque" because I don't like it.




btw, Lc is the length of the crows foot.



An example with numbers would seem to indicate your original assumptions are not accurate.

Dave this part of your formula works well and it looks neat and easy.

(TD X LW) / (LT + LW) = TS

That is a beautiful thing there.

And it works out for the numbers I tried.

Sincerely,

William McCormick

[William McCormick]

Dave this part of your formula works well and it looks neat and easy.

(TD X LW) / (LT + LW) = TS

That is a beautiful thing there.

And it works out for the numbers I tried.

Sincerely,

William McCormick

I am going to use those formulas, to test against them in the real world and see how they stand up to reality.

Here is how I checked your formula, it is the same way I checked out my cumbersome formula.

For a one-foot crow's foot, and a two-foot torque wrench scenario that wishes to achieve 100-foot pounds of torque on a bolt. Both formulae spit out 40 pounds of torque, which means there are 20 pounds of tangential force on the wrench handle to achieve that. 20 times the overall length of the torque wrench and crow's foot is 3, 3 times 20 achieves 60 ft. pounds of lever force on the bolt. Then there are the additional 40 pounds of rotational force calculated by the formula that gives us 100-foot pounds of torque on the bolt combined. These are the tests I plan to do with both wrenches and the scale.

The standard formula says that we need 66.66666666666666666666 foot-pounds of torque at the wrench to achieve 100 foot-pounds on the bolt, divided by two gives us 33.333333333333333333333 pounds of tangential force on the handle of the torque wrench. 33.333333333333333333333 times 3 equals 100 pounds f lever force calculated at the bolt. But we have an extra 66.66666666666666666666 of accumulated torque in the head of the torque wrench on top of the 100 pounds of lever force which should yield 166.666666666666666 ft. pounds of torque to the bolt.

I want to get a large two handle tap handle and add rotational force to the torque wrench head as well just to demonstrate the rotational force's involvement at a rotating joint in a lever.

Sincerely,

William McCormick

[William McCormick]

I think there is something with the checking that goes off the rails but the formula is amazing.



Sincerely,


William McCormick

[MinnesotaDave]

I am going to use those formulas, to test against them in the real world and see how they stand up to reality.

Here is how I checked your formula, it is the same way I checked out my cumbersome formula.

For a one-foot crow's foot, and a two-foot torque wrench scenario that wishes to achieve 100-foot pounds of torque on a bolt. Both formulae spit out 40 pounds of torque, which means there are 20 pounds of tangential force on the wrench handle to achieve that. 20 times the overall length of the torque wrench and crow's foot is 3, 3 times 20 achieves 60 ft. pounds of lever force on the bolt. Then there are the additional 40 pounds of rotational force calculated by the formula that gives us 100-foot pounds of torque on the bolt combined. These are the tests I plan to do with both wrenches and the scale.

The standard formula says that we need 66.66666666666666666666 foot-pounds of torque at the wrench to achieve 100 foot-pounds on the bolt, divided by two gives us 33.333333333333333333333 pounds of tangential force on the handle of the torque wrench. 33.333333333333333333333 times 3 equals 100 pounds f lever force calculated at the bolt. But we have an extra 66.66666666666666666666 of accumulated torque in the head of the torque wrench on top of the 100 pounds of lever force which should yield 166.666666666666666 ft. pounds of torque to the bolt.

I want to get a large two handle tap handle and add rotational force to the torque wrench head as well just to demonstrate the rotational force's involvement at a rotating joint in a lever.

Sincerely,

William McCormick

I still say that "the new formula" is incorrect.

If the crows foot is clipped directly to the torque wrench, it is being turned by rotational force.
Just so happens both swing in an arc together that is easy to see.

When the crows foot is on the end of a socket extention, it is still being turned by the same force.

Your other hand just balances the torque wrench head. Which should result in a negligible error.

I could be wrong, but I'm going with it

If I'm wrong, then the original time tested formula should include the disclaimer that the longer the socket extension, the less accurate the result. Then that can be tested and a correction for error determined, and an error calculation included.

I would find all of that quite interesting.

[William McCormick]

I think there is something with the checking that goes off the rails but the formula is amazing.



Sincerely,


William McCormick

I know what happened there Dave, your wife came into the room and whispered Y over X on the square mattress, haha.

Sincerely,

William McCormick