VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > The Never Ending Debate Section > Tools
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #251  
Old 02-17-2012, 06:28 PM
CMW CMW is offline
 
Join Date: Mar 2007
Location: Livermore, CA
Posts: 167
Default

Quote:
Sorry, but I don't agree with that. Get a one-foot ruler out and have a look at it; does that look like the length of the sort of torque wrench you'd use on 7/16" nuts? Remember, we are talking about a wrench specifically designed for propeller nuts.
Bob, you're probably right. I just based that statement on the fact that my 100lbs-ft clicker wrench happens to have a 12 inch effective length. My old beam style wrench is 17" (weird).

Mike,

Quote:
There is no way I can hold that much if it were a simple lever.
I don't know, you look pretty stout.
__________________
Chris
RV-8 Wings
Reply With Quote
  #252  
Old 02-17-2012, 07:46 PM
Captain Avgas Captain Avgas is offline
 
Join Date: Oct 2005
Location: Melbourne, Australia
Posts: 1,868
Default

Quote:
Originally Posted by LifeofReiley View Post
JMHO... this Gentleman, Allan has PAID for advertisement space on VAF. He has posted a Classified Ad, not a discussion thread. At what point do stop beating on Allan for his PAID advertising? If you like his products, buy them. If you have a question about them, call him. If I remember correctly folks getting BANNED for beating up PAID adverisers here on VAF...
Well, in the words of Doug Reeves himself, VansAirforce is "a place for people building and flying RV kitplanes to socialize, network, get inspiration and receive help from others". My best guess is that the current discussion falls firmly into the latter "helping each other" category. There are obviously many educated people on this forum who firmly believe that Allan is providing incorrect, and potentially unsafe, information and they subsequently feel an obligation to point out that fact to others. And in my opinion they would be morally bankrupt if they did not do so.
__________________
You’re only as good as your last landing
Bob Barrow
RV7A

Last edited by Captain Avgas : 02-18-2012 at 01:17 AM.
Reply With Quote
  #253  
Old 02-17-2012, 11:17 PM
444TX 444TX is offline
 
Join Date: Dec 2005
Posts: 155
Default Wow

I can not wait to see Allan's video example. He is completely correct and knows it. For many it will be very educational

The biggest problem is the poor formula for torque extensions. Allan's example in post #22 is no exeption.

When converting, 12 inches is always used with ft/lb and 1 inch is always used with in/lb for "L" in the equation. This applies to all types of torque wrenches when using the indicated reading on the wrench.

If the handle length is used the amount of neccessary force applied to the handle is calculated and would have to converted back to ft/lb's.

George
RV8
Reply With Quote
  #254  
Old 02-18-2012, 07:12 AM
WAM120RV WAM120RV is offline
 
Join Date: Dec 2006
Location: Coventry. England
Posts: 614
Default Spanner in the works

So, I have 2 foot long torque wrench but instead of pulling it at the handle, I decide to pull it in the middle 1 foot down its length.......will this alter the setting required.

It seems to me that a lot of intelligent people are getting themselves tied in knots trying to understand whats going on here.

For Allans extension spanner to provide 100lbs/ft at the nut, it requires a certain pressure applied at the attachment point to the torque wrench. The amount of pressure will not change no matter how long the torque wrench is. What will vary is the amount of pressure applied by the operator to the torque wrench handle, and the amount of stroke required.

Think about your joy sticks and the effect of varying their length. The loads on the control surfaces dont change, but the load you have to apply to the stick does vary, and the amount you have to move it.

Your mileage and stick length may vary
__________________
http://www.aerobuilder.blogspot.com


Steve Arnold
England

In completion stage of Loehle P5151
Built and now Flying G.BVLR Vans RV4
Rebuilt G.BDBD Tailwind
Rebuilt G BVTN Kitfox
Built G CDCD RV9A with WAM120
Riveted wings on Glastar G.LEZZ Now (G. SKUA)
Reply With Quote
  #255  
Old 02-18-2012, 07:16 AM
380mxc's Avatar
380mxc 380mxc is offline
 
Join Date: Oct 2010
Location: Pa...
Posts: 47
Default Ac 43.13-1B

Can someone show me how the formula in AC43.13-B figure 7-2 for the torque wrench adapter is wrong.

It dissagrees with using .8 as a constant.

My torque wench manufacturer says the handle length is 22.57 inches and my extension is 3".

If the formula from AC43 is used, 70.61lbs shoud be my setting on the wrench
If the .8 constant is used, 64lbs should be my setting on the wrench.

Thanks for your help
Tim
Reply With Quote
  #256  
Old 02-18-2012, 07:55 AM
fehdxl fehdxl is offline
 
Join Date: Mar 2005
Location: Bellevue, NE
Posts: 686
Default

Quote:
Originally Posted by 380mxc View Post
Can someone show me how the formula in AC43.13-B figure 7-2 for the torque wrench adapter is wrong.
Nope. AC43.13-B is correct. Y=(T*L)/(L+E)

-Jim
Reply With Quote
  #257  
Old 02-18-2012, 08:51 AM
WAM120RV WAM120RV is offline
 
Join Date: Dec 2006
Location: Coventry. England
Posts: 614
Default Try this link

http://www.freeinfostuff.com/TorqueE...eExtension.htm
__________________
http://www.aerobuilder.blogspot.com


Steve Arnold
England

In completion stage of Loehle P5151
Built and now Flying G.BVLR Vans RV4
Rebuilt G.BDBD Tailwind
Rebuilt G BVTN Kitfox
Built G CDCD RV9A with WAM120
Riveted wings on Glastar G.LEZZ Now (G. SKUA)
Reply With Quote
  #258  
Old 02-18-2012, 09:37 AM
Bob Kuykendall's Avatar
Bob Kuykendall Bob Kuykendall is offline
 
Join Date: Sep 2006
Location: Douglas Flat, CA
Posts: 589
Default

Quote:
Originally Posted by WAM120RV View Post
So, I have 2 foot long torque wrench but instead of pulling it at the handle, I decide to pull it in the middle 1 foot down its length.......will this alter the setting required...
It depends on the type of torque wrench being used. For a clicker or dial indicator type, the indicator or click will be accurate, since the measurement is entirely internal to the wrench. However, you will have to apply twice the force at the 1-foot mark as you would at the handle to achieve the same torque at the nut.

Edit add: It turns out I might be wrong about part of this. A video linked from a later post seems to demonstrate that applying force to the middle of a torque wrench will disrupt its accuracy. However, it does not sway my conviction about the invalidity of the "0.8 correction factor."

For a beam-style wrench, the indication will not be accurate if you apply force at any place except at the handle. The accuracy of the indication scale near the handle depends on the beam being loaded in simple bending by a force applied at the center of the handle. Most such wrenches have a rocking pivot built into the handle that ensures that the force is applied to the beam only at the correct point.

Quote:
Originally Posted by WAM120RV View Post
It seems to me that a lot of intelligent people are getting themselves tied in knots trying to understand whats going on here...
It seems to me that a lot of people are putting a lot of effort into clarifying what is going on because it is a safety of flight issue with potentially deadly consequences.

Quote:
Originally Posted by WAM120RV View Post
...For Allans extension spanner to provide 100lbs/ft at the nut, it requires a certain pressure applied at the attachment point to the torque wrench...
Statements like that tend to be the places where this discussion goes off the rails. We are not talking about pressure here, we are talking about forces and torques. Those three things are very different and have very specific meanings. We have to keep our terms straight in order to discuss this intelligently.

A force is, well, a force, aplied at a point. Forces are measured in units like pounds or Newtons. A pressure is a force applied over an area. The air in your tires applies a pressure something like 30 lbs per square inch to the inner surface of the tire.

A torque is the result of a force applied at some distance from an axis that causes bending or rotation. Torques are measured in in-lbs, ft-lbs, Newton-meters, and things like that. An inch-pound is the torque that results from a force of one pound applied at a distance of one inch from the axis. A Newton-meter is a force of one newton (there are nominally 9.8 newtons per kilogram) applied at a distance of one meter from the axis.

You might ask, if the Metric system is decimal, why are there 9.8 Newtons per kilogram, and not ten? It's because the Newton is a measurement of force that is independent of the 9.8 meter-per-second^2 acceleration of gravity. But that might be the start of a discussion for a different day.

Thanks, Bob K.
__________________
Bob Kuykendall
HP-24 kit sailplane
EAA Technical Counselor

Last edited by Bob Kuykendall : 02-18-2012 at 02:30 PM.
Reply With Quote
  #259  
Old 02-18-2012, 09:43 AM
Bob Kuykendall's Avatar
Bob Kuykendall Bob Kuykendall is offline
 
Join Date: Sep 2006
Location: Douglas Flat, CA
Posts: 589
Talking

Quote:
Originally Posted by WAM120RV View Post
Nice, thanks for posting that! It is a good description of what is going on, and the calculator makes it easy to test different combinations of wrench length, extension length, and torque value.

Thanks, Bob K.
__________________
Bob Kuykendall
HP-24 kit sailplane
EAA Technical Counselor
Reply With Quote
  #260  
Old 02-18-2012, 09:59 AM
WAM120RV WAM120RV is offline
 
Join Date: Dec 2006
Location: Coventry. England
Posts: 614
Default Totally Agree

Bob

I totally agree about the potential dire consequences, and forgive my poor choice of words, should have said force.

I think the point I was trying to make is that there are a lot of opinions and calculations going on here which I suspect would cause more confusion. Also trying to put a light side on the thread.

Bottom line is if you search the web there is usually a calculator set up to do the mathematics for you.
__________________
http://www.aerobuilder.blogspot.com


Steve Arnold
England

In completion stage of Loehle P5151
Built and now Flying G.BVLR Vans RV4
Rebuilt G.BDBD Tailwind
Rebuilt G BVTN Kitfox
Built G CDCD RV9A with WAM120
Riveted wings on Glastar G.LEZZ Now (G. SKUA)
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 02:16 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.