quattro Digest, Vol 6, Issue 17

[Larry C Leung]

At the risk of restarting this old thread, if the 
crows foot extends the length of the handle to
point of torque application, then it WILL affect
the torque reading. If, as Charles Penning suggests,
you turn the crow's foot 90 degrees to the wrench
axis, the slight increase in distance (along the theoretical
hypotenuse) is soooooo slight as to render any difference
pretty much moot. Now, the shorter the wrench handle,
the greater the percentile difference, no matter which
way the crow's foot is attached to the head. 

Remember the torque formula, assuming applied force
is done perpendicular to the wrench handle is

F x D = Torque, where F is the applied force, and

                D is the distance from the applied force
                point to the object being torqued.

If D changes (and F doesn't), torque is changed,
parallel axis or not. 

LL - NY





> Date: Tue, 6 Apr 2004 09:39:22 -0500
> From: "Flanner, Chris" <cflanner at aosmith.com>
> Subject: Torqueing knock sensor/crow's foot
> To: <quattro at audifans.com>
> Message-ID:
>         <BF5CF60FC3A2344988D6DFBDEFB2AC43033618 at whqex01.aosmith.org>
> Content-Type: text/plain;        charset="us-ascii"
> 
> Here's how I see it . . .
>  
> Changes in the location of the crow's foot relative to the socket
> connection of the torque wrench (I'll call it the "head") has no 
> effect
> on the reading as long as the head and the crow's foot apply torque 
> in a
> parallel axis.  No matter where the torque is applied by the crow's 
> foot
> (or socket or whatever) the equal and opposite torque is seen at 
> any
> desired point in any parallel axis including the torque wrench's 
> head
> where it is converted to an indication.  Only the force on the 
> torque
> wrench handle and the equal and opposite reaction force at the 
> fastener
> change when the position of the crow's foot changes.  This, of 
> course,
> ignores the effect of friction on torque readings but that's another
> issue.
>  
> Am I wrong?
> 
>