>From my jet engine mechanic days in the Air Force I offer the following. You
>don't need to use the torque wrench in the computation as it is already
>calibrated for its length. If you add any extension to the end of the torque
>wrench you have to adjust for the additional arm length. Our tech orders had
>a formula to use which took into account the length of the extension including
>a crowfoot. However, if the crowfoot was used at 90 degrees to the torque
>wrench no adjustment was required. The calculation involved the angle and
>length of the extension, not the diameter. Most of the time using a
>crowsfoot, especially for small torques there was very little difference of
>the torque wrench setting. Since most specs are within a range, the
>calculated setting was still in the specified range. You still had to do all
>of the calculations just to make sure.
Pete
-----Original Message-----
From: Triumphs <triumphs-bounces at autox.team.net> On Behalf Of TERRY SMITH
Sent: Saturday, August 11, 2018 8:56 AM
To: Sujit Roy <triumphstag at gmail.com>; Randall <tr3driver at ca.rr.com>;
triumphs at autox.team.net
Subject: Re: [TR] torque wrench question
LOL! I'm just glad you science guys are out there!
> On August 11, 2018 at 5:51 AM Randall <tr3driver at ca.rr.com> wrote:
>
>
> > Uhm, that would be why English majors subscribe to this list....
> >
>
> Perhaps an example would help?
>
> Let's say you want to torque your nut to 50 ftlb, your torque wrench
> measures 26" overall and your crowfoot extension is 4" overall.
>
> First we need the effective length of the torque wrench. On mine, the
> business end is about 1" diameter, while the hand grip extends about 2"
> beyond the center of my hand. So we subtract half of the head
> diameter
> (0.5") and the 2" for the hand grip to get 23.5" effective length.
>
> Now the effective length of the torque wrench plus crowfoot extension.
> Assuming both ends of the crowfoot are around 1" diameter, it would
> extend the center by about 3", or 26.5" overall.
>
> Divide those two numbers to get the ratio. 23.5/26.5 = .89 (rounded
> to 2
> digits)
>
> Multiply the desired torque by the ratio. 50 * .89 = 44.5 ftlb. Round
> that to two digits, and set your wrench to 45 ftlb.
>
> Hmm, well, perhaps not. Reminds me of an old David Crosby line: "You
> see just below the surface of the mud, there's more mud here."
>
> -- Randall
>
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