VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics


Go Back   VAF Forums > Model Specific > RV-7/7A
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 06-07-2010, 05:01 PM
LettersFromFlyoverCountry's Avatar
LettersFromFlyoverCountry LettersFromFlyoverCountry is offline
 
Join Date: Jan 2005
Location: St. Paul, MN.
Posts: 4,792
Default 7A wing bolt orientation

The only drawing I can find in the plans regarding wing bolts is for a 7, not an "A" model. Obviously on the taildragger, having all bolts oriented from front to back is certainly not a problem. But with the gear weldments, some of the bottom bolts must be oriented back to front, right?

Also, I'm torquing the rear spar attach bolt and looking up the proper torque to use. Is this bolt a fine thread or course thread bolt and how does one distinguish the two?
__________________
Bob Collins
St. Paul, MN.
Blog: Letters From Flyover Country
RV-12iS Powerplant kit
N612EF Builder log (EAA Builder log)

Last edited by LettersFromFlyoverCountry : 06-07-2010 at 05:58 PM.
Reply With Quote
  #2  
Old 06-07-2010, 07:07 PM
terrykohler terrykohler is offline
 
Join Date: Jan 2005
Posts: 1,009
Default Check out the Fastener Section at Your Local Hardware

U.S. fasteners are specified in "threads per inch". The fine thread versions are the ones with greater Thread Per Inch count. IIRC, there are no coarse threaded fasteners used anywhere in the airframe. Regarding bolts facing fore or aft, the orientation should be to allow the most accessible tightening of the nut. Never tighten the bolt, as you'll get an unreliable torque/clamp results due to the added friction.
Terry, CFI
RV-9A N323TP
Reply With Quote
  #3  
Old 06-07-2010, 07:19 PM
apkp777's Avatar
apkp777 apkp777 is offline
 
Join Date: Oct 2008
Location: Schaumburg, IL
Posts: 2,053
Default

Bob,

I had to put some heads forward and some aft. It was not possible to torque the nuts all facing the same direction.
__________________
Tony Phillips
N524AP, RV 9 (tail wheel)
Reply With Quote
  #4  
Old 06-07-2010, 08:51 PM
jimski9's Avatar
jimski9 jimski9 is offline
 
Join Date: Apr 2006
Location: Tauranga, New Zealand
Posts: 27
Wink

Bob

DWG11 shows all the bolt heads aft. Washers under the nuts for the top bolts and washers under the bolt heads for the lower ones. Be careful inserting the lower outer big bolts. If they go in too far before you get the nut started you will have a problem trying to back them out again. Don't ask me how I know

Jim Talbot
New Zealand
RV7A
Flying!
Reply With Quote
  #5  
Old 06-07-2010, 11:35 PM
Flying Scotsman Flying Scotsman is offline
 
Join Date: Nov 2005
Posts: 1,256
Default

Quote:
Originally Posted by terrykohler View Post
U.S. fasteners are specified in "threads per inch". The fine thread versions are the ones with greater Thread Per Inch count. IIRC, there are no coarse threaded fasteners used anywhere in the airframe.
Correction...on the -7A, the socket head cap screws that go through the gear leg at the wheel to hold the brake flange, etc., take a 1/4-20 nut. The shank of the screw is 5/16, the threads are 1/4-20. Torque to 1/4-20 specs, not 5/16. Ask me how I know this.

This is the only place I found on the airframe with coarse threads...
__________________
Steve "Flying Scotsman"
Santa Clarita, CA
PP-ASEL, ASES, Instrument Airplane

RV-7A N660WS flying!
#8,000
Reply With Quote
  #6  
Old 06-08-2010, 07:45 AM
LettersFromFlyoverCountry's Avatar
LettersFromFlyoverCountry LettersFromFlyoverCountry is offline
 
Join Date: Jan 2005
Location: St. Paul, MN.
Posts: 4,792
Default

Quote:
Originally Posted by jimski9 View Post
Bob

DWG11 shows all the bolt heads aft. Washers under the nuts for the top bolts and washers under the bolt heads for the lower ones. Be careful inserting the lower outer big bolts. If they go in too far before you get the nut started you will have a problem trying to back them out again. Don't ask me how I know
But I don't believe Drawing 11 is referencing an "A", it's referencing a tail dragger without the landing gear weldments.
__________________
Bob Collins
St. Paul, MN.
Blog: Letters From Flyover Country
RV-12iS Powerplant kit
N612EF Builder log (EAA Builder log)
Reply With Quote
  #7  
Old 06-08-2010, 07:53 AM
rzbill's Avatar
rzbill rzbill is offline
 
Join Date: Nov 2005
Location: Asheville, NC
Posts: 2,692
Default AN hardware is fine as frog hair

Hey Bob,
It is my understanding and experience that all common AN bolt hardware would be classified as "fine" threads or "UNF".

I know there are exceptions such as engine fasteners and #8 and smaller screws but for AN3 bolts and above, I think they are all fine thread.
__________________
Bill Pendergrass
ME/AE '82
RV-7A: Flying since April 15, 2012. 850 hrs
YIO-360-M1B, mags, CS, GRT EX and WS H1s & A/P, Navworx
Unpainted, polished....kinda'... Eyeballin' vinyl really hard.
Yeah. The boss got a Silhouette Cameo 4 Xmas 2019.

Last edited by rzbill : 06-08-2010 at 07:57 AM. Reason: screw note
Reply With Quote
  #8  
Old 06-08-2010, 08:50 AM
Jim Percy Jim Percy is offline
 
Join Date: Mar 2005
Posts: 179
Default

Pretty sure DWG 11 applies to the "A" models as well. In fact, I don't see any reason to have the washers under the lower bolt heads on a tail dragger.

Quote:
Originally Posted by jimski9 View Post
Be careful inserting the lower outer big bolts. If they go in too far before you get the nut started you will have a problem trying to back them out again. Don't ask me how I know
This is good adivce!
__________________
Jim Percy
SoCal
FFI Wingman
RV-7A, XP-O-360
Reply With Quote
  #9  
Old 06-08-2010, 03:04 PM
LettersFromFlyoverCountry's Avatar
LettersFromFlyoverCountry LettersFromFlyoverCountry is offline
 
Join Date: Jan 2005
Location: St. Paul, MN.
Posts: 4,792
Default

Final ruling from Van's -- the orientation of the bolt doesn't matter. Whatever makes it easiest to torque the nut.
__________________
Bob Collins
St. Paul, MN.
Blog: Letters From Flyover Country
RV-12iS Powerplant kit
N612EF Builder log (EAA Builder log)
Reply With Quote
  #10  
Old 06-08-2010, 08:48 PM
GAHco's Avatar
GAHco GAHco is offline
 
Join Date: Dec 2006
Location: Paso Robles, CA
Posts: 1,177
Talking Think about it / A little more info!

Quote:
Originally Posted by Bob Collins View Post
Final ruling from Van's -- the orientation of the bolt doesn't matter. Whatever makes it easiest to torque the nut.
Thanks Bob,
Vans is correct (no surprise)

When a representative sample of these bolts are destructively tested after manufacture, they are supposed to break at or above a certain tension. The only acceptable failure point is the root of the threads close to the transition area where the unthreaded shank and the threads meet.
That is the tensile test.

The shear test applies the the full cylindrical portion of the unthreaded shank, depending on the fastener it may be cut in two with a special shear jig or put in a special jig to just proof load the shank.

The bottom line is a bolt will be just as strong either way it is installed.

If a nut and bolt combination would fail due to installation direction of the bolt there would be due to a serious mismatch of fastener to structure.
__________________
Get em in the Sky!
Tom Brink Pres.
GENUINE AIRCRAFT HARDWARE Company
www.gen-aircraft-hardware.com

www.gen-aircraft-hardware.com/site_tips.asp


28th Anniversary of GAHco March, 2012
Thanks for being part of our success
Dues Paid November 2012
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 05:36 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.