Home > VansAirForceForums

-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

VAF on Twitter:

Old 06-10-2022, 03:46 PM
hk1232's Avatar
hk1232 hk1232 is offline
Join Date: Jan 2022
Location: Minneapolis, MN
Posts: 8
Default Adjusting Spar and Rib Flanges

Working on my RV-9 empennage and notice the flanges on the ribs and spars aren't at a 90. I expected this.

Was looking to build out the tool discussed in this thread:

But I notice that the tool seems to be angled to adjust over-bent flanges. Spot checking both ribs and spars I see they are all under-bent.

  1. Are mine already "square enough" and you recommend taking no action?
  2. Am I looking at the tool mentioned in the referenced thread wrong and it will in fact work with what I have?
  3. Have you built a reversible tool that corrects for both over- and under-bent flanges?
Attached Thumbnails
Click image for larger version

Name:	Flange square - IMG_8309.jpg
Views:	57
Size:	398.1 KB
ID:	26873  Click image for larger version

Name:	Flange square - IMG_8310.jpg
Views:	56
Size:	345.0 KB
ID:	26874  
Reply With Quote
Old 06-10-2022, 04:18 PM
hk1232's Avatar
hk1232 hk1232 is offline
Join Date: Jan 2022
Location: Minneapolis, MN
Posts: 8

Ok I'm looking at the tool more closely now -- this will do what I'm looking for.

Assume the hive mind opinion is that these two examples are in fact under-bent and should be adjusted to a straight 90?
Reply With Quote
Old 06-10-2022, 04:25 PM
RBR RBR is offline
Join Date: Nov 2006
Location: Brisbane, Australia
Posts: 91
Default Please do not adjust the angle of the spar!

Are we looking at the VS?

The 'angle' you are considering adjusting is designed to pickup the taper in the skin as it angles back from a skinny leading edge to a chunkier trailing edge.

If you cleco the structure together you will get a better overview. When it is all together you will get to see the geometry.

As for the ribs, the adjust & flute process will likely have moved the angle again! So re-check the angle after fluting.

Hope this helps!

Is there an EAA Chapter nearby?
VAF # 1565,
RV-8. Showplanes and Todd's canopy. Sam James cowl.
Aero Sport Power IO-375 & WWA 74RV.
First flight 30 August 2018
RV-14A slow build in progress
Reply With Quote
Old 06-10-2022, 04:56 PM
David Paule David Paule is offline
Join Date: Dec 2009
Location: Boulder, CO
Posts: 5,576

That's my tool in post #3 in that thread. It worked well whenever I had a flange like yours, regardless of which direction it needed to go. But as the previous poster wrote, some flanges aren't supposed to be at 90 deg. to the web, so check first.

Reply With Quote
Old 06-10-2022, 05:57 PM
wirejock's Avatar
wirejock wirejock is offline
Join Date: Oct 2005
Location: Estes Park, CO
Posts: 5,890
Default Flange bending

Like Dave mentioned. Make sure the flange should be adjusted. Spars usually don't need it. Ribs usually but not alwsts. Dave's tool flexes past square then the flange reflexes to 90. It works like a charm.
Larry Larson
Estes Park, CO
E-mail: wirejock at yahoo dot com
Builder Blog:
Donated 12/2022, plus a little extra.
RV-7A #73391, N511RV reserved
I cannot be, nor will I be, held responsible if you try to do the same things I do and it does not work and/or causes you loss, injury, or even death in the process.
Reply With Quote
Old 06-11-2022, 07:31 PM
Marc Bourget Marc Bourget is offline
Join Date: Apr 2009
Location: Stockton, California
Posts: 407

Consider forming the rib flange to 85-87 deg and rolling the edge of the rib flange a bit more.

I've seen where the flange will "relax" or open up when riveting and with flight load cycles, leaves a crease in the skin.

Reply With Quote

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 07:16 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.