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
  #261  
Old 02-18-2012, 10:08 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
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.
Steve, my apologies for the brusque tone. The page you posted earlier, with the example and the calculator helps a lot to clarify what is going on here.

Thanks, Bob K.
__________________
Bob Kuykendall
HP-24 kit sailplane
EAA Technical Counselor
Reply With Quote
  #262  
Old 02-18-2012, 10:19 AM
WAM120RV WAM120RV is offline
 
Join Date: Dec 2006
Location: Coventry. England
Posts: 614
Default Here is another one

Bob

To be fair I was being a little naughty, in an attempt to lighten the tone. I was not actually expecting an answer, so no offense taken

Here is a better calculator which allows you to work out the torque setting when the crows foot is at different angles. The interesting point is that when it is at 90 degrees, you set the actual torque required on the nut.

http://www.cncexpo.com/TorqueAdapter.aspx

Perhaps I am getting lazy, although I could understand the maths if I dug into it, I don't need to.......... the web is fantastic!
__________________
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
  #263  
Old 02-18-2012, 11:22 AM
CMW CMW is offline
 
Join Date: Mar 2007
Location: Livermore, CA
Posts: 167
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.
Steve - Bob,

Please watch this video. It shows that for a clicker wrench you should not use it by grasping it in the middle. It will alter the setting required.

http://www.youtube.com/watch?v=_1LZk...Ru2bTi566Hn1Lf
__________________
Chris
RV-8 Wings
Reply With Quote
  #264  
Old 02-18-2012, 11:39 AM
L.Adamson's Avatar
L.Adamson L.Adamson is offline
 
Join Date: Apr 2005
Location: KSLC
Posts: 4,021
Default

Quote:
Originally Posted by CMW View Post
Steve - Bob,

Please watch this video. It shows that for a clicker wrench you should not use it by grasping it in the middle. It will alter the setting required.

http://www.youtube.com/watch?v=_1LZk...Ru2bTi566Hn1Lf
After reviewing this video several times on a big screen, I can see that the movement of the arm, of "dial" torque wrench............is much more, when the click wrench is grasped at half it's length. It would seem, that this could effect the measurement we're looking for. Just an observation, as I have no facts.
Reply With Quote
  #265  
Old 02-18-2012, 11:42 AM
WAM120RV WAM120RV is offline
 
Join Date: Dec 2006
Location: Coventry. England
Posts: 614
Default Thanks

Chris

Thanks for posting this. In a previous life I served an engineering apprenticeship and would never hold the clicker or beam wrench in the middle. I hope what I said does not give anyone the idea that it OK to do this. As the video shows holding the wrench in the middle increases the force applied on the nut.

Your video should show the folly of this. Actually, we used to use a type of crows foot to tighten cylinder heads which put the drive directly over the bolt being tightened, so no correction factor was required for varying length torque wrenches.

All this discussion reminds me of a TV show many years ago called Tomorrows World. The topic was tightening nuts and bolts and the elastic limit of bolts. From memory ( which is getting a bit dodgy), the best way of ensuring the bolt was tightened to its maximum without exceeding the elastic limit was a very accurate measurement of the bolt length/stretch. The second best was a skilled craftsmans hands, and they showed that some people were almost as accurate by feel. The torque wrench came in third.

The tendency for the mere mortals is to over tighten, so a torque wrench is essential.
__________________
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)

Last edited by WAM120RV : 02-18-2012 at 11:47 AM. Reason: More info
Reply With Quote
  #266  
Old 02-18-2012, 02:22 PM
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 CMW View Post
Steve - Bob,

Please watch this video. It shows that for a clicker wrench you should not use it by grasping it in the middle. It will alter the setting required.

http://www.youtube.com/watch?v=_1LZk...Ru2bTi566Hn1Lf
Thanks, Chris. That is not the result I would have expected. It doesn't sway my conviction regarding the "0.8 correction factor," but it does seem to support the idea that you should only apply force at the handle of a torque wrench.

Thanks again, Bob K.
__________________
Bob Kuykendall
HP-24 kit sailplane
EAA Technical Counselor
Reply With Quote
  #267  
Old 02-18-2012, 02:38 PM
444TX 444TX is offline
 
Join Date: Dec 2005
Posts: 155
Default Well

After research it seems all is not as simple as first thought. The common calculations using torque wrench arm length in calculations appear to be correct and my simple math and Allan's .8 conversion are incorrect.

There was the exact same scenario questioned on the physics forum. http://www.physicsforums.com/showthr...=432352&page=2

Allan's explanation/video should be very interesting.

George
Reply With Quote
  #268  
Old 02-18-2012, 02:44 PM
WAM120RV WAM120RV is offline
 
Join Date: Dec 2006
Location: Coventry. England
Posts: 614
Default Correction factor

George

Allan is correct that for a 1 foot torque wrench with a 3 inch crows foot the correction factor is .8 if held in line.
__________________
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
  #269  
Old 02-18-2012, 02:59 PM
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
George

Allan is correct that for a 1 foot torque wrench with a 3 inch crows foot the correction factor is .8 if held in line.
Yes, Allan is correct for that one specific case of the 12" torque wrench. He is incorrect for all other lengths. It similar to the broken clock being right twice a day.

Thanks, Bob K.
__________________
Bob Kuykendall
HP-24 kit sailplane
EAA Technical Counselor
Reply With Quote
  #270  
Old 02-18-2012, 05:32 PM
sstellarv10 sstellarv10 is offline
 
Join Date: Feb 2009
Location: Southbridge,MA
Posts: 193
Default

Wow Allan, you couldn't have asked for any better advertising than this thread has created.
__________________
Steve Stella
#40654 Finishing
N521RV reserved
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.