bill ftw
Yes
No
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05-09-2011
bill ftw
05-09-2011
Even if you have a 100% perfect fitting extension you are still going to lose torque. The extension will still twist and cause loss of torque due to length.
05-09-2011
Please read my previous post. Twistin an extension does not result in a loss of torque. It only results in a greater turn required to compensate for the twist. The reason why an impact behaves differently is because it is an impact. That creates a scenario many times more difficult to calculate. I stand by the science that I KNOW is true, you do not lose torque due to extensions.Originally Posted by stealthee
05-09-2011
You have to pull more to make up for the twist, so yes that is a loss of torque.
A better way to word it is, you have to apply MORE torque to make up for the twist. If you aren't losing torque then you would not have to apply more.
05-09-2011
Maybe if you think of it this way. Hold a spring in your hands. Try to push harder with one hand than the other. What happens? You end up moving your hands in the direction of the weaker push. In order to keep a spring in place, you must push equally hard with both hands. similarly, you must twist a rod equally on both sides in opposite directions to maintain a net force of zero, as you do when you are tightening the bolt to a set torque.
05-09-2011
Maybe if you think of it this way. Hold a spring in your hands. Try to push harder with one hand than the other. What happens? You end up moving your hands in the direction of the weaker push. In order to keep a spring in place, you must push equally hard with both hands. similarly, you must twist a rod equally on both sides in opposite directions to maintain a net force of zero, as you do when you are tightening the bolt to a set torque.
05-09-2011
Cast your votes ppl... It sounds like it's gonna be a significant split.
05-09-2011
10 people should take mechanics of materials for mechanical engineering lol
05-10-2011
Ok guys.. guess what I did?
I researched this further. That's right. Tossed my opinion and biases aside and cracked some ... ok I googled.
ZR1 from a scientific standpoint appears to be correct. I looked up some torque wrench manuals etc and while I was sure I had read it in one that the torque changes, they all stated only if you add length to the torque wrench, not if you added extensions. (length making the wrench longer in total length).
Torque away guys.
BTW, this should prove that while someone like me is confident and sounds right...you should always research and question things.I do.
05-10-2011
The reservation to the extension thing is a weevil wobble. I believe those things do mess with your torque, for the same reason you don't see very sharply angled ones in a drive shaft.
05-10-2011
I did find the wobble mention. Since I will not acknowledge them as actual extensions, only as thirds...aka rejected extensions. I don't bother to consider them viable.
05-10-2011
Hahaha fair enough. We did have to use one one time while swapping out the intake/exhaust manifold on an I6 jeep. The rear bolt is virtually impossible to get to.I did find the wobble mention. Since I will not acknowledge them as actual extensions, only as thirds...aka rejected extensions. I don't bother to consider them viable.
05-10-2011
This is such an easy question and is answered in any physics 101 class in college.
You don't lose torque because of extensions distance. The reason why you wont appear to input as much torque is because of the angle on the bolt or because of the slop in between the extensions.
05-10-2011
reading some of your posts, my mind= blown.
05-10-2011
The extra "give" you get from the extensions not being a direct fit will not matter once you turn the extension. Because at that point, the extensions are touching and no "give" is allowed anymore. So essentially. It's like having one long extension, regardless of how many there are.
05-11-2011
I didn't have to do a physics class for my Business degree. Last physics was high school..and yea, even college was a few years ago.
05-11-2011
Just came across this thread.
As explained by others, torque is not lost through any length of extension.
What is happening, is that the creation of slop in the extensions makes it more difficult to apply the torque.....without stripping the head of the bolt.
When using a long extension, I torque the ratchet with one hand and hold the ratchet/extension junction with the other hand. The perceived sense of stripping the bolt head contributes to the difficulty in tightening the bolt.
Imagine you welded a socket to a bolt, then solidly welded a bunch of extensions to the socket and a ratchet. Nobody would sense a loss of torque. You would get a crapload of deflection (bending), but you wouldn't lose torque.
In summary, its fair to say extensions reduce effectiveness felt by the user, but they do not affect torque.
Oh, and impact effectiveness is also reduced when using extensions, because of slop in the system. Say the impact is applied for 1/8 of a rotation. If you wiggle the extensions and notice 1/8 rotation of slop....well obviously very little energy is being transmitted to the bolt.
05-12-2011
Ok... off with my sheep's clothing now that it seems we've gotten to the bottom of the issue. I must admit, this was not a "real" concern of mine (hence the poll) but something I was interested in getting a consensus on.
I started this thread while I was working last Saturday with a friend of mine who happens to be a 30-year mechanic. He was going to put some lug nuts on and nonchalantly said, "Darn, I'm gonna have to use an extension - oh well, I'll just crank up the torque by 10 ft-lbs or so." (on the torque wrench). I started to tell him that it's not like that but it was clear he wasn't convinced so I backed off (he's a 30-year mechanic for goodness sake!)
Most of the main points were already covered by previous posts, so I'll just clarify. In addition to creating slop, extensions DO flex themselves, even with no slop in the connections. However, this flex in no way affects the torque felt by the bolt. You must expend additional energy to carry the torque through the angle, and that is why we perceive that we are applying more torque, when in fact we are simply working harder (work = torque x angle traveled). Clear as mud? Haha
Now, for the impact wrench, things are much more complicated physically. The extension is no longer relatively motionless, and the mechanism for tightening the bolt is entirely different. The extension can be modeled as a mass-spring-damper system, just like a coilover strut. When we roll over a pothole in our car, the force exerted on the wheel is of enormous magnitude and a very short duration. However, the force felt by the chasis and the driver is spread out over a much longer time, and has a much smaller magnitude. The same thing happens when you use an extension with an impact wrench.
This also sheds some light on how torque sticks work. Just as you can design a suspension to be as stiff or soft as you like, you can choose extensions that will be as stiff or soft as you like. Both affect the magnitude of the force (or torque) applied at the end.
Hope this explanation helps!
05-12-2011
^^^ Good summary
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