ugly post formatting! [was: my take on torque]

[auditude at cox.net]

What's up with that non-wrapped post?  How do I change that?  I'm using webmail, and I don't know of any options for that.  There is a line width option, but it is for display, not composition.

I hit enter after each of the lines below.  Maybe it'll be easier to read, not that it's fun to do.  Or, maybe it'll have those stupid "=" signs throughout.

Ken

auditude at cox.net wrote:

While half-following the thread on torque and all the 
answers offered, at one point I forgot what the question 
was.  But I think the question is how much torque is 
actually applied to the crank bolt when following the manual 
using the recommended tools and technique.

I'm not familiar with the math involved in calculating the 
resultant torque at the bolt using the tool, which probably 
has a known length.  But is the math formula being disputed? 
 Is there more than one being offered?

To me it seems intuitive to think that any torque wrench of 
any length is intended to produce the same torque at the 
bolt when used as intended.

I do believe the factory tool is a torque multiplier, as 
well as a way to get to the bolt without pulling too much off the front of the car.

I don't know enough about this stuff to be able to say 
whether putting a pipe or extension on the handle end of a 
torque wrench will affect it's accuracy.  I am temped to say 
that it will, since I believe you are not supposed to touch 
the wrench anywhere but the handle.  If I put my hand in the 
middle of the torque wrench opposite the direction of force, 
for example if I was pulling up on the handle, I imagine the 
hand in the middle of the wrench would reduce the amount of 
"handle" force getting to the bolt.

I believe the above is only relevant because were are 
talking about improperly using the torque wrench.  I think 
the discussion about torque wrench length is totally 
pointless.  If you use a 2 foot torque wrench properly or 
use a 2 mile torque wrench properly, the resulting torque at 
the bolt is the same.

So in summary, I think the torque applied by any correctly 
used torque wrench is measured at the socket.  So the 
question becomes, what is the torque at the bolt when the 
stupid factory tool is used?

I'm sure I don't understand the rest of it (and maybe the 
part above!), because there has got to be something more for 
there to be such a long thread.  I suspect adding length 
from the socket end of the torque wrench is not the same as 
adding length to the torque wrench itself.  (by that I mean 
using a longer torque wrench, which wouldn't change the 
applied torque, but would require less force on the handle 
end, and more distance)

It's possible that a simple formula for extending the lever 
could be used to calculate torque.  But, my hunch is that 
since the "click" occurs in "the middle" of the combined 
torque wrench/factory tool, instead of near the bolt, there 
there is another factor to consider.

The one analogy about the four corners of the torque wrench, 
pushing in four directions, seems to make a little sense.  I 
don't know what happens with the "extra" three directions of 
force, but the only direction that the torque wrench can go 
is the direction the crank bolt is turning.  So, the torque 
wrench is pushing the factory tool clockwise with a certain 
amount of force.  If that force is multiplied by the factory 
tool due to its length, then it should be calculable.

Hmmm.  So if the "click" point of the torque wrench is not 
at the same point as the center of the bolt being tightened 
(it's in between that point and the handle), then at that 
point it is not measuring the "twist" that's occuring at the 
bolt, but the force applied in a single direction at the 
click point.

So, by using the factory tool you are moving the click point 
further away from the axis of the bolt than it already is.

My conclusion is that the formula for calculating the effect 
of lever length on torque should be applicable to this 
problem.  In other words, adding length to either side of 
the click point should have the same effect, since it is 
measuring force in a single direction, and not the "twist" 
dimension (directly).

Make sense?  Or just more talking out of asses? :P

I also believe that getting it as tight as possible with 
whatever you can manage is probably fine as long as you have 
some grunt.

Cheers,

Ken