NEW! Ultimate C/S Prop Wrench Anti Splat Aero

[WAM120RV]

Allan

The best compliment I can give you is to ask whether you are really Dilbert in this cartoon. http://www.youtube.com/watch?v=FlJsPa6UwcM

I love your intuitive answers to 'our' problems.

[380mxc]

L is a variable for handle length
Bottom line if you use .8 and your handle is longer than 12 inches your bolts will be under torqued.

http://gizmodo.com/5881485/pilot-sav...ched-in-flight

Safety First

Tim

[gstone]

L is not substituted for the length of your torque wrench. .8 was determined bu the length of the extension being 3 inches and it multiplying the torque by .25 (becasue it is one fourth of the length of a foot lb) thereby needing a reduction at the setting of whatever torque wrench to .8 of the desired torque product. The torque applied to the extension to get 100 lbs of torque will be 80 lbs set on ANY wrench no matter the length of said wrench.

[erich weaver]

Just when I had hopes this was reaching a resolution...

Its not like primer wars or the nose dragger/tail dragger arguments. One side is just plain wrong here.

Bob K's drawings and explanations seemed simple and straightforward. Can Allan or others in the "0.8 is a constant" camp explain succinctly where they are in error? Simply insisting that 0.8 is a constant as proven through 7th grade math isnt very convincing. There are some experienced, smart folks that made it through 7th grade and well beyond that say otherwise, and they have some convincing documentation that appears to back them up. I have yet to see ANY published documentation that makes the case for using a constant multiplier for a torque wrench extension of a given size regardless of the length of the torque wrench. Staying open minded however...

Somebody kidnap Dan Horton and refuse to release him until he takes a stand on this

erich

[mike newall]

Steve,

Brilliant........

Sent to all the mechanics I know

[PerfTech]

Originally Posted by WAM120RV

Allan

The best compliment I can give you is to ask whether you are really Dilbert in this cartoon. http://www.youtube.com/watch?v=FlJsPa6UwcM

I love your intuitive answers to 'our' problems.

Thank you Steve for the compliment! I am beginning to feel like him (Delbert). This thread is actually beginning to scare me. The lack of understanding I am witnessing here could potentially have costly or dire consequences impacting safety. I am somewhat in disbelief!

[Bob Kuykendall]

Originally Posted by PerfTech

...
Now forget all you think you know about this and listen. Pretend for a moment you have no idea what a torque wrench is and have never seen one. The .8 multiplier is a constant that applies to our prop wrench and does not change. Our 3" tool is simply a torque multiplier period, nothing else. If you use this tool on your bolts, it and it alone boosts the power of what ever devise you use to tighten the bolts by a factor of plus 20%. That requires you to set your tool, be it your weight lifter mother in-law or a heavy rock on a rope to EXACTLY 80% of the desired value. THIS IS A FACT AND WILL NOT CHANGE under any circumstances. This is 7th grade math, not rocket science. If you are looking for 70ft.lb. on your bolts 70 X .8= 56ft.lb. setting on what ever you use to pull with.
... Now I need to search out a formula to re-calculate the 3.1416 number in pie as it will no longer hold true because I am using a longer pencil to do the math.

I'm sorry, but all the color, exclamation points, and emoticons in the world aren't going to make you right. Go back to your statics textbook and study the chapters on moments and rigid bodies. As I have shown, they are the basis for the simple applications of physics behind the formulas for torque wrench correction embodied in AC43.13.

Edit Add: Really, I encourage you to find a real mechanical engineer and have them explain this to you. Trust me, it will be better for you and for your ability to develop and promote your products.

Thanks, Bob K.

[Birkelbach]

Originally Posted by PerfTech

Bob has it exactly!!!!!!!!!
Now forget all you think you know about this and listen. Pretend for a moment you have no idea what a torque wrench is and have never seen one. The .8 multiplier is a constant that applies to our prop wrench and does not change. Our 3" tool is simply a torque multiplier period, nothing else. <<SNIP>>

If I forget all that I know about this then I guess I could be convinced that you are correct, but you are NOT correct. Your little device is NOT a torque multiplier. It is a lever. A lever is a FORCE MULTIPLIER. The math has been done here to the extent that I don't know why we are still arguing about it but let me try my hand.

Say I have a 2' long torque wrench. I grip the wrench on it's handle and apply 100 ft-lbs of torque to it. That'll be 50 lbs of force at the handle. Now I add your extension, and apply that same 50 lbs of force (the wrench will still read 100 ft-lbs because it has no way of knowing about the extension). Now I am applying 50 lbs of force at a distance of 2.25 ft. That is 112.5 ft-lbs. That is a multiplier of 0.8889 and 0.8889 is not equal to 0.8.

Guys seriously. This is not complicated. These are prop bolts that we are talking about. Let's get it right.

[L.Adamson]

Originally Posted by Bob Kuykendall

I'm sorry, but all the color, exclamation points, and emoticons in the world aren't going to make you right. Go back to your statics textbook and study the chapters on moments and rigid bodies. As I have shown, they are the basis for the simple applications of physics behind the formulas for torque wrench correction embodied in AC43.13.

I'd still like to see definate proof, beyond all doubt...........that the spring release mechanism of a "click" torque wrench, has to comply with the same physics that apply to a beam torque wrench. While the tables presented so far, make perfect sense for a "beam", how do they really relate to a compressed spring?

L.Adamson

[ccsmith51]

if this is all a very clever marketing plan to keep the wrench at the top of the new posts lists for days on end...