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Correct Term for Unbalanced Rotational Force?


Jim Katen

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I'm having a hard time coming up with a correct term.

Let's say you have a wing nut. When you turn it, you exert (mostly) even forces on each wing.

Now suppose that one of the wings has broken off. When you turn it, you now exert a lateral force in addition to a rotational one.

What's the term for this unbalanced force? I thought of eccentric, but it seems like there's a better one out there.

- Jim Katen, Oregon

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I'm having a hard time coming up with a correct term.

Let's say you have a wing nut. When you turn it, you exert (mostly) even forces on each wing.

Now suppose that one of the wings has broken off. When you turn it, you now exert a lateral force in addition to a rotational one.

What's the term for this unbalanced force? I thought of eccentric, but it seems like there's a better one out there.

- Jim Katen, Oregon

It's a torque either way. With an unbroken wing nut, the torque is generated by twin symmetrical force vectors or twin mechanical moments. With one wing broken, the torque is generated by a single force vector and friction force.

At least that's what I think.

Marc

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Now suppose that one of the wings has broken off. When you turn it, you now exert a lateral force in addition to a rotational one.

What's the term for this unbalanced force? I thought of eccentric, but it seems like there's a better one out there.

I wouldn't call it eccentric, since to me that conotes how it moves about center, and my grandmother would have no idea what I was talking about. If I had a situation where force had been applied evenly in rotation, I would tell my grandma that the force is now applied unevenly, which will cause a problem, i.e. vibration, out of roundness, etc.

Chris, Oregon

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Let's say you have a wing nut. When you turn it, you exert (mostly) even forces on each wing.

Now suppose that one of the wings has broken off. When you turn it, you now exert a lateral force in addition to a rotational one.

Isn't that effectively what happens when you apply a torque wrench (actually any single handled wrench) to a nut? The unmoving bolt creates the pivot point and forces the lateral movement of the wrench to become rotational...but there's still an uneven force being applied.

So I'm going to go with "off-centered torque".

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The wingnut is broken, replace it.

I'm suprised I have to explain this.

Good answer. But it's not the answer to the question I asked.

This has almost nothing to do with home inspections by the way.

It's just a pure question with no application. A long series of sychronized events got me to thinking about it and wondering what word would describe it.

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Couple is a vector quantity where you have a moment arm and an applied force.

It is sometimes described as torque, but it's a little different, I think.

It could be applied along with eccentric, but only mechanical engineers would know what you're talking about.

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The force is single moment. The resulting momentary flex and twist, which will vary with the material, is the result of torsion. Does a torsion bar on vehicle cover pretty well all of the foces you're dealing with?

(I noticed after posting that Kevin had already mentioned "torsional", but discounted it. Actually, torsion, by definition, does seem to best describe all of the forces and variables, though. Since the axis is not fixed, the torsion will be momentary and tough to calculate.)

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