Torque Wrench Checking

Attach the wrench to something that won't turn and pull on the handle with an accurate spring scale.

Dick

Yes, a different brand and attach it to the other wrench and turn one and the other and see if they both have readings that are similar... its like checking a tape measure... use another scale to measure it and see if it is correct.....

Will try the spring scale technique first and then another torque wrench if possible.

Yep, especially with a weightless lever arm...Course, you could put a dummy 3 foot arm on the opposite side of the pivot point. (Ducking....)

How do you know there *both* not wrong? After all, "Two wrongs don't make a right." Or, as the cuckolded guy from Hong Kong said to his wife upon seeing the baby she'd just delivered, "Honey, two Wongs don't make a white."

Jeff

Jeff Wisnia wrote: Yep, especially with a weightless lever arm...(clip)^^^^^^^^^^^^^^^ Since weightless levers, though " ideal", are hard to find, you could just include the torque due to the weight of the wrench, in your calculations. Weigh the wrench, and locate its center of gravity by balancing it.

Did you know that you can find the balance point by supporting it on the edges of your hands, and then just moving your hands together? Works. Try it.

Torque wrenches can be calibrated by larger aircraft shops. They have the necessary machines which are certified accurate, and a license to do the testing. They'll adjust the wrench if it's adjustable, and send back a chart showing indicated vs. true torque. They test the unit from 25% to 100% of its torque range. Takes some time. But this doesn't come cheap. I paid about $80 apiece for my Husky 3/8" and 1/2" drive wrenches, and another $60 each to test and set them. And aviation law in Canada requires that they be retested every two years. If you're working on airplanes, of course.

Dan

The first thing I did was ask a friend at a big aircraft shop to check mine with their equipment.They farm their wrenches out for calibration.My uses for the wrenches are not that critical.The fees asked for calibration aren't worth it for my purposes. I like the KISS principle.My arms are 3 ft.long but my pockets I keep at 40 inches.

Sure is- it's called a tool dealer. He'll send yours out for recalibration if it's a better quality wrench. A cheap beam wrench- don't bother.

-Carl

On Mon, 13 Oct 2003 16:06:48 GMT, "Leo Lichtman" wrote something ......and in reply I say!:

Careful. Only on a smooth object, or one with small enough, and totally equally spaced roughness that the movement is not obstructed more in one direction than another. Not just being picky. This is a DAMHIKT situation. Once you have found the "balance point" then make sure it balances.

****************************************************************************************** Whenever you have to prove to yourself that you are not something, you probably are.

Nick White --- HEAD:Hertz Music Please remove ns from my header address to reply via email !!

Neet trick, Leo. I take it it works (in theory) only if the coefficient of friction of the object of interest is the same along it's length, and you're ambidextrous too, so both your hands are equally calloused.

Jeff

-- Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to place the blame on."

Old Nick wrote: (clip) This is a DAMHIKT situation. Once you have found the "balance point" then make sure it balances. ^^^^^^^^^^^^^ I could not find DAMHIKT in my glossary of acronyms. So, I will just respond to the part I do understand. The method is self-checking. If the CG winds up where you expect it, the "thing" will be balanced on the edges of your hands. If for some reason the CG is not there, it will fall to the side which is heavier. That would be a dead giveaway. I suppose you could contrive to make the method fail, by, say, putting in a notch, or cleat, which would obviously prevent that hand from moving. However, of all the things I have ever tried, the friction was even enough to make it work. I think it is because any minor variation in friction is swamped out. An error produced by a difference in the coefficient of friction produces a corrective moment, so the force decreases on that side, and pretty soon things are moving the way they should again. Perhaps if the friction were consistently higher on one side of the CG, it would fail to slide properly.

On Tue, 14 Oct 2003 17:57:03 GMT, "Leo Lichtman" wrote something ......and in reply I say!:

Don't Ask Me How I Know This. (I have experienced this problem myself)

Your hands provide a high-enough "fulcrum to allow quite a large error. Balance the thing at the point you found, just to make sure. Sometimes it does not work, because without my makking a deliberate effort, there is already some obstruction.

I am sorry. I agree that the idea works well. I have had a thing where I found that I had to really balance the object, and move what I though was the centre of balnc a little.

****************************************************************************************** Whenever you have to prove to yourself that you are not something, you probably are.

Nick White --- HEAD:Hertz Music Please remove ns from my header address to reply via email !!

Here's another DAMHIKT, again using just your hand.

If you need reading glasses to see small stuff.......

If you suddenly find you left your reading glasses at home and are stuck trying to read something like a phone number you need to dial, or a reading on your mike, do this:

Wrap the thumb of one hand over the index finger and shift your thumb around until you've created a small opening near the base of your index finger. Put one eye against this hole and hold what you've got to read about an inch beyond that hole.

BINGO, you've created an instant pin hole lens without much depth of field or field of view, but it's absolutely better than nothing, especially if the illumination is good.

Try it, you'll be suprised at what it can do.

I wonder if the ancients knew about this one before whathisface invented the glass lens?

Jeff

this hole and

field of view,

Wow-it really works well!

I learned this trick daydreaming in school in the fifth grade.I had one of those Eberhard Faber erasers and was just reaming a hole through it with a newly sharpened pencil.Voila,was really surprised how good I could see through it.Didn't know I needed glasses until 2 years later.

On Wed, 15 Oct 2003 02:36:58 GMT, Jeff Wisnia wro

field of view,

A pinhole has no focal plane, and hence has great depth of field.

field of view,

Count on you to catch me on that one Don. I used the wrong term there; What I was trying to say is that the text you're trying to read has to be the "right" distance away from the pinhole for maximum efficiency. Howzatt?

Now please go check in at:

Jeff

or field of view,

was trying to say

the pinhole for

Hey, this is a precision group, Jeff! What does DAMHIKT mean, anyway?

This trick also works for reading the wattage on an illuminated ceiling-mounted lightbulb while standing on the floor. If the hole is small enough, it dims the image enough to read the label.