VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics

  #41  
Old 03-02-2015, 07:10 AM
GLPalinkas's Avatar
GLPalinkas GLPalinkas is offline
 
Join Date: Jan 2005
Location: Venice, Fl
Posts: 1,020
Default

Quote:
Originally Posted by BillL View Post
Gary, that looks good, but the only issue might be hydroforming the skin around the spar. You should look and see. It might be hard enough not to do that. Let us know if you see creases along the spar.

Load transfer is the most difficult issue in jacking a plane, getting loads to the heavy parts.
Bill, I'll check with the RV-8 owner and see but I would think the line guys or FBO wouldn't use it if damage occurs (then again, hmmmm)
__________________
Gary Palinkas - Gman.... VAF #161
Venice, Fl
RV-6 "Sassy" Flying 400 hrs since Oct 2011
Lycoming 0-360 A1A, FP Sensenich Prop
SARL #19 .... Van's Calendar March 2015
Although exempt several ways, =VAF= Dues paid to support this awesome site/family
Reply With Quote
  #42  
Old 03-02-2015, 07:23 AM
rwwende rwwende is offline
 
Join Date: Feb 2010
Location: Ankeny, IA
Posts: 55
Default

Quote:
Originally Posted by kkmarshall View Post
I know there are many methods & opinions but I jack one side at a time by using a 1ft 2by12 well padded under the main spar just inboard of the gear leg. Steady as a rock. I am not the builder but he gave me that advice & it works well. YMMV
Keith
Keith, I do the same. Works very well.
Reply With Quote
  #43  
Old 03-02-2015, 07:40 AM
Snowflake's Avatar
Snowflake Snowflake is offline
 
Join Date: Oct 2009
Location: Victoria, BC, Canada
Posts: 3,932
Default

Another suggestion for Jack's new call sign could be "Punch". That's almost a nice clean hole.

This reminds me of the time one of the people was working in the rafters of the hangar at our local airport, and accidentally knocked a 2x4 free... It fell straight down and went through the wing of an Emeraude. By blind luck it hit dead center between two ribs and between the front and rear spar, damaging no structure... Just the fabric top and bottom. Still, you get the same sick feeling when you see a 2x4 standing *through* a wing as you do seeing the hole in the bottom of yours.
__________________
Rob Prior
1996 RV-6 "Tweety" C-FRBP (formerly N196RV)
Reply With Quote
  #44  
Old 03-02-2015, 07:54 AM
Ron RV8's Avatar
Ron RV8 Ron RV8 is offline
 
Join Date: Nov 2010
Location: Okanagan Valley BC, Canada
Posts: 483
Default

Quote:
Originally Posted by scrollF4 View Post
Ron,
What did you use to countersink the hole at the top of the jack piston?
You're pushing my synapses here...

I think I drilled up to about 1/2" then used a die grinder, but I could also have used the drill press to drill larger...

I really don't think the precision matters much, as long as you have a hollow to retain the bolt head...
__________________
Ron Townson
Okanagan Valley BC, Canada
RV-8 Completed Dec 2013

Membership renewed Sept 8, 2019
Reply With Quote
  #45  
Old 03-02-2015, 08:14 AM
douglassmt douglassmt is offline
 
Join Date: Nov 2008
Location: Missoula, MT
Posts: 714
Default

Quote:
Originally Posted by Jackm View Post
We learn from others mistakes...at least I hope I do. In my case I must be number one to do this and I admit to being a Idiot ( I am so glad Bryan Douglass hasn't seen this cause he would confirm) but it can be prevented by coming up with a much more fail safe solution. Therefore our solution is this and I feel confident we will only fix one wing in my lifetime
https://www.dropbox.com/s/ninxmc4hb4...51050.jpg?dl=0
Wow, Jack, that really sucks. Thanks for posting as I'm getting ready to do this for my third annual. I'll look over my design and modify accordingly. I have always lifted one side at a time and tried to be very gentle when it's up in the air. No matter, it still bears looking over the jacking method. I'm not sure that from now on I won't use BOTH the wing tied-down point and a second jack under the spar box on that side as a back up - to steady the plane and to spread the load.

As for you being an idiot, I don't think so. I saw no mention of liquid plumber - unless you're holding back
__________________
Bryan Douglass
=VAF= 2020 dues paid
RV-10 N242BD
Reply With Quote
  #46  
Old 03-02-2015, 08:54 AM
rvbuilder2002's Avatar
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 9,035
Default

Quote:
Originally Posted by Jackm View Post
In my case I obviously was too aggressive and a idiot...but I will say it is recipe for outcome like ours.
My opinion is that your situation happened because of the type of interface you were using on the top of the jack.

As long as the jacking pin is short and it interfaces to something on the jack that can't move (cone shaped recess, etc.) the risk of the pin breaking and/or it slipping off is very low. As already mentioned in numerous posts so far, the critical factor is the pin must be short so that the bending load on the pin/bolt is low.

Based on the photo of your failed "cap", I have a strong feeling that it was actually forcing a bending load on the bolt since your pin was essentially restrained at both ends (threaded into the cap and the wing tie down) there was no unrestrained pivot point. This put a concentrated bend load on the bolt.
__________________
Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.

Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
Reply With Quote
  #47  
Old 03-02-2015, 12:40 PM
JDanno JDanno is offline
 
Join Date: Apr 2008
Location: Tennessee
Posts: 440
Default

Quote:
Originally Posted by kkmarshall View Post
I know there are many methods & opinions but I jack one side at a time by using a 1ft 2by12 well padded under the main spar just inboard of the gear leg. Steady as a rock. I am not the builder but he gave me that advice & it works well. YMMV
Keith
That method works very well. We have been using it on several RV-10s for the last three years.
Reply With Quote
  #48  
Old 03-02-2015, 03:18 PM
alpinelakespilot2000 alpinelakespilot2000 is offline
 
Join Date: Jan 2005
Posts: 3,646
Default

I've been using the wing jack but like it increasingly less, whether with a bolt in the tie down or a cap in the tiedown. Either way the wing rotates a bit as it's jacked up so the jack will never stay totally centered under the tie down, leaving one with some potential for catastrophic failure.

As an alternative, and one that's much more universally available if you find yourself stranded someday is shown in post#15 of this thread: http://www.vansairforce.com/communit...jacking&page=2. Gary Sobek's version here: http://www.vansairforce.com/communit...ad.php?t=68449
Apparently Van's even used to sell the ubolt and bracket version but it looks like a stainless hose clamp works too. Light for sure, plus it can be done with the universally available automotive scissor jack. Perhaps even more important, if anything slips here there's only a matter of a couple inch drop with likely nothing damaged in the process. Downsides???
__________________
Steve M.
Ellensburg WA
RV-9 Flying, 0-320, Catto

Donation reminder: Jan. 2021

Last edited by alpinelakespilot2000 : 03-02-2015 at 03:38 PM.
Reply With Quote
  #49  
Old 03-02-2015, 03:54 PM
Bavafa Bavafa is offline
 
Join Date: Oct 2007
Location: Sacramento, CA
Posts: 3,351
Default

Quote:
Originally Posted by alpinelakespilot2000 View Post
As an alternative, and one that's much more universally available if you find yourself stranded someday is shown in post#15 of this thread: http://www.vansairforce.com/communit...jacking&page=2. Gary Sobek's version here: http://www.vansairforce.com/communit...ad.php?t=68449
Apparently Van's even used to sell the ubolt and bracket version but it looks like a stainless hose clamp works too. Light for sure, plus it can be done with the universally available automotive scissor jack. Perhaps even more important, if anything slips here there's only a matter of a couple inch drop with likely nothing damaged in the process. Downsides???
This is exactly how I lift up my RV and I believe it is a much easier and safer way.
__________________
Mehrdad
N825SM RV7A - IO360M1B - SOLD
N825MS RV14A - IO390 - Flying
Dues paid
Reply With Quote
  #50  
Old 03-02-2015, 03:56 PM
sblack sblack is offline
 
Join Date: Dec 2009
Location: Montreal
Posts: 1,456
Default

Don't feel too bad. I have seen several large commercial airplanes that have come off jacks and punctured wings - jacking done by professional mechanics with the right jacks but something got missed. We're all just hooman beans.

My wings are not closed out yet so you can bet I will be reading through this thread in great detail to see what I can do right now to make future work easier. Thank you all for sharing.
__________________
Scott Black
Old school simple VFR RV 4, O-320, wood prop, MGL iEfis Lite
VAF dues 2020
Instagram @sblack2154
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 12:53 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.