VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics


Go Back   VAF Forums > Model Specific > RV-8/8A
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 01-08-2020, 05:59 PM
kens_cockpit's Avatar
kens_cockpit kens_cockpit is offline
 
Join Date: Jan 2005
Location: Launceston, Tasmania, Australia
Posts: 79
Default Fuel tank attachment to fuselage - large gap F863 to T405

After many years doing other things I have returned to complete my RV8 project. I will not make any jokes about the kit being Quickbuild this being the 16th year since it was delivered to my garage. My youngest daughter has no memory of a car ever being in the garage. I am back on board now.

I have attached the wings according to the instructions and drilled the rear spar attach with the appropriate amount of incidence and sweep.

I have come to match the front fuel tank angle bracket (T405) to the fuselage front spar attach angle (F863) which I previously fabricated in accordance with the plans. It is anticipated those angles will not meet precisely because the instructions call for me to bend the F863 in the following terms:

?Adjust the main web by clamping it in a bench vise and hitting with a large hammer while protecting it with a block of wood.?

But in this case there is a large gap of about 3/8 to 13/64 between the rear face of the angle attaching to the fuselage and the fuel tank support as shown in the attached photos. I don?t think I could bend the fuselage angle as fabricated to bridge that gap while maintaining a flush fit between the facing surfaces of the angles.

Solutions seem to me to be:

1. To shim the gap ? this seems to be simplest.
2. Construct another angle to attach to the fuselage with a longer flange on the fuselage side so the edge distance can be maintained. This is relatively simple although I will need to order the angle again and have it shipped to Australia at significant cost. If solution 1 was viable and no less satisfactory I would prefer to do that.
3. Attempt a complicated multi angle bend to allow for the surfaces to meet flush. I don?t think I could achieve this successfully.
4. Persist with the instructions as per the plans and settle for the tip of the F863 to meet the web of the T405. That seems to be a weak solution which could lead to concentration of forces at the intersection of pieces.

Can I please have the wisdom of this forum about this?
https://lh3.googleusercontent.com/uZ...g=w811-h608-no

https://lh3.googleusercontent.com/o3...g=w811-h608-no
__________________
Ken Stanton
RV8 QB

Wing attach
Building a plane again after building family

We inhabit a mystery. We should not pretend to know too much.
-Eugene Peterson
Reply With Quote
  #2  
Old 01-11-2020, 04:33 PM
8 Builder 8 Builder is offline
 
Join Date: Aug 2014
Location: Lowell, MA
Posts: 84
Default Gap

Hi Ken-
I completed this step a short time ago. Your pictures are not visible to me but if you have a gap that large, and you have made the F863's correctly, then I would venture a guess that something is positioned in a backward position. Let us know what you find.
__________________
Rich Snyder
Building RV-8
Superior IO-360
Garmin G3X Touch, VFR
Fixed Catto 3 blade
Reply With Quote
  #3  
Old 01-11-2020, 04:46 PM
rv8ch's Avatar
rv8ch rv8ch is offline
 
Join Date: Feb 2005
Location: LSGY
Posts: 3,145
Default something's wrong

Quote:
Originally Posted by 8 Builder View Post
...I completed this step a short time ago. Your pictures are not visible to me but if you have a gap that large, and you have made the F863's correctly, then I would venture a guess that something is positioned in a backward position. Let us know what you find.
Same here - just did this, and also can't see the pictures. My guess is that something is wrong, and/or you need to re-make those angles. Mine fit flush.
__________________
Mickey Coggins
http://rv8.ch
"Hello, world!"
Reply With Quote
  #4  
Old 01-11-2020, 06:04 PM
sjhurlbut sjhurlbut is offline
 
Join Date: Jan 2005
Posts: 832
Default Gap

I had a gap also. Hammer away. You can bend it no prob
__________________
Visit and subscribe to Stu's Aircraft Factory on

https://www.youtube.com/channel/UCGQ..._as=subscriber

Steve "Stu"
Cold Lake, Alberta
7A #70015 - C-FZQX - built - sold
7A #71629 - C-FSIS - built - sold across Atlantic
7 #70215 - C-GOJU - flying - sold
7 #70703 - C-GMIY - flying - sold
6 #60119 - C-FHBZ - built - Airventure 2016 Bronze Lindy - sold
8 #82842 - C-FSBG - Fastback - built - sold
4 #2723 - building
Reply With Quote
  #5  
Old 01-11-2020, 11:25 PM
Andy612's Avatar
Andy612 Andy612 is offline
 
Join Date: Jun 2012
Location: Whitehorse, Yukon Territory
Posts: 19
Default Gap

I suspect an RV-8's F-863 is similar to an RV-4's F-463. On my Rv-4 fuel tank rebuild I had to open up the angle on F-463 considerably to match it to T-405.

Instead of hammering, a piece of heavy steel tube and a vice were used to open the angle, like in this video: https://www.eaa.org/Videos/Hints-for.../4186755302001
__________________
Andy Muir
C-GJIP RV-4 160hp
Based at CYXY
Reply With Quote
  #6  
Old 01-12-2020, 07:25 AM
Carlos151's Avatar
Carlos151 Carlos151 is offline
 
Join Date: Jan 2008
Location: Lebanon, TN
Posts: 271
Default

Quote:
Originally Posted by kens_cockpit View Post
I have attached the wings according to the instructions and drilled the rear spar attach with the appropriate amount of incidence and sweep..
Is it possible the wing sweep is too much? That would certainly increase the distance between the fuel tank bracket and the fuselage front spar attach angle.

I also cannot see the pictures you?re trying to post. Here?s a link on how to post pictures from Google:

https://ctrlq.org/google/photos/
__________________
Karl Richcreek
RV-8
N151TK "La Otra Chica"
Flying as of August 14, 2015
TN26
Reply With Quote
  #7  
Old 03-21-2020, 05:19 AM
kens_cockpit's Avatar
kens_cockpit kens_cockpit is offline
 
Join Date: Jan 2005
Location: Launceston, Tasmania, Australia
Posts: 79
Default

Vans said I should make the F863-1. That is 3/8" wider on the flange that attaches to the fuselage so it fixed the problem. Now I just have to figure out how to backdrill from the inside of the fuselage into the F863-1. it's very tight
__________________
Ken Stanton
RV8 QB

Wing attach
Building a plane again after building family

We inhabit a mystery. We should not pretend to know too much.
-Eugene Peterson
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 03:03 PM.


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.