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Thanks, Bob K. |
I answered this question from Mike Starkey in another thread on this debate:
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The nut will see absolutely no torque at all.Think about it or try it out to prove to yourself that it's true. I think this proves the correction multipler cannot be a constant. Hope that helps. -- Stephen |
90 degrees
For the love of mary, put the thing on 90 degrees and be done with it! Or calibrate your elbow... seriously. Does anybody really torque spark plugs, an 3 bolts, brake backing plates or mag attach nuts?
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I torque spark plugs every time. One stripped thread in the cylinder isn't worth it to me. Without a torque wrench, I tend to over-torque stuff, especially AN-3 stuff.
I really have to watch it!........ :o |
Sorry to do this, but . . .
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So . . . Mike's pure torque of 100 will result be resisted by an equal torque at the nut. There are no force couples involved. the distance is not relevant since there is no force couple involved. OK, all ready to pull your hair out now? Think about it . . . if you applied a pure torque to that wrench and it was not attached, what would happen - it would spin, right? So the reaction at the nut can NOT be zero and the real answer is it is equal to that applied. For the extension - use the FAA and torque wrench book formula. Why? Lets say the FAA is correct - the factor is not fixed at 0.8 . But I use the 0.8 anyway. The prop torque needs 60-70 ft-lb of torque. I usually use the middle number since i don't know which way my tool may be inaccurate. So let's use 65 ft-lb. If I use a 16.5 inch wrench ( my real number) and using the .8 factor, I will be actually 6.7% low, according to the FAA formula. What if my click wrench is 4% low? Then I am 10.7% low now, or only 58 ft-lb of real torque on the nut. That is 2 ft-lb below the low end of the range. Is that enough to worry? I don't know, so I will be using what my engineering training, experience, and the FAA formula tells me. |
It is after midnight...
I just had to see what all the huboob was about and clicked on this thread. I read every post to page 11. I said to my aching brain...let's skip to the last page and there I will find out if the length really does matter. Okay, I can sleep tonight since I have been flying behind my prop that was torqued with a 90 deg adapter. We used the same formula that is in AC43.13 in the military. I would hate to have to go back and recheck torques from 23 years ago. I am going to bed, my calibrated elbow is hurting too.
Now I figured out why Mike Starkey was recommending to a new builder "torque wrench how-to lessons" before starting his -10 emp. I was wondering what kind of crazy recommendation was that.:D |
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Found a nice online calculator
It even (correctly) takes into account the angle-off of the adapter.
http://www.cncexpo.com/TorqueAdapter.aspx Try putting an angle of 180 degrees in, see what happens. You can change the length to see the results as well. |
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-- Stephen |
Both could be right! Advanced Statics....
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In case 1, you do your best to hold the impact driver still. In doing so, you provide a reaction force that counters the wrench interaction on the nut. You get a force couple that cancels the moment, with no torque on the nut. In case 2, you do not resist the motion of the impact wrench, only its rotation. The wrench will try to orbit the nut, and in doing so, transmit the pure torque to it with no force couple. This assumes it does not orbit so fast that centrifugal force throws it off the nut though! :rolleyes: |
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