Mike,
Yes, with respect - assuming you refer to the "spanner and wrench in
straight line" method:
Conider the case when you set the torque for 25 in lbs:
- Assume that the wrench is 10 in long (distance from grip to attachment
to spanner)
- A fraction of force before the wrench clicks, the pull then is a
fraction less than 2.5 lbs (10 in x 2.5 lbs = 25 in lbs)
- Assume that the spanner also is 10 in long.
- Just before the wrench clicks, the force of 2.4999999 lbs has a lever
of 10 in (wrench) + 10 in (spanner) = 20 in on the bolt, i.e. a torque
of 20 in x 2.5 = 50 in lbs.
- Look at it this way: Just before the wrench clicks, the set-up does
not know that it is about to break. There is therefore only one stiff
piece between your pull of 2.5 lbs and the bolt, and that piece is 20 in
long. Using a torque wrench as an extension to the spanner limits your
maximum pull, you might say, in this case to 2.5 lbs so that the torque
on the bolt cannot exceed 50 in lbs - the click breaks any stronger
pull.
Best regards,
Svein
----- Original Message -----
From: DuaneFamly@aol.com
To: europa-list@matronics.com
Sent: Tuesday, September 12, 2006 6:07 PM
Subject: Re: Europa-List: prop bolts
Svein and Others,
I'm not sure I agree with this method. I don't think the torque wrench
knows how long a handle is exerting the force. I think that it will
still "click" at the setting you set it at. If the proper setting is 50
inch lbs (EU's have to do the conversion) and you set it the torque
wrench for 25 inch lbs, then the wrench is going to click when you have
25 inch lbs exerted on it. And your bolt is only torqued to 25 inch lbs,
not 50. Making the handle longer only allows you to have to exert 1/2
the pressure to get that 50 inch lbs to the torque wrench.
Am I missing something here?
Mike Duane A207A
Redding, California
XS Conventional Gear
Jabiru 3300
Sensenich R64Z N
Ground Adjustable Prop
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