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 04-28-2016, 05:45 AM
tsw94r tsw94r is offline
 
Join Date: Apr 2016
Location: Monroe, Ga
Posts: 8
Default Elevator Trailing Edge Bend

Hello All,

I'm ready to make the final bend on the elevators. The instructions tell you to follow the profile on the plans, but I can't find the profile to save my life.

I understand how to make the bend, just not what the trailing edge should look like when I'm done.

Tom
Reply With Quote
  #2  
Old 04-28-2016, 07:35 AM
wjb's Avatar
wjb wjb is offline
 
Join Date: Nov 2012
Location: Half Moon Bay, CA
Posts: 734
Default

The closest thing I found was Dwg 4 zone G-10, which shows a end view of the elevator.

The skin needs to be bent down so both sides touch the spar. I followed the suggestions in the aileron section to make the surface up to the final bend as flat as I could .. use a straight edge from leading edge to trailing edge and check for a concave or convex profile and adjust to make surfaces a flat as you can.

Also, before bending, double check your stiffeners to be sure they won't interfere with each other or the opposite surface when the skin is in its final shape.

Go slow, too. IIMC, it took quite a few pressings to get it just right. Overall, its not a hard op.
__________________
Bill Bencze
N430WB (reserved) RV-7 #74152, tip-up. Engine is in the house!
Log at: http://rv7.wbencze.com
Defeating gravity one rivet at a time
VAF 2018 donation happily made
Reply With Quote
  #3  
Old 04-28-2016, 10:03 AM
tsw94r tsw94r is offline
 
Join Date: Apr 2016
Location: Monroe, Ga
Posts: 8
Default Elevator Trailing Edge Bend

Thanks Bill,

I appreciate the tips. It sounds like there really isn't a profile to go by at least in the plans.
__________________
Tom Wormsley
Slow Build RV-7, 3rd build, Emp 80%, Wings kit in shop
D73
Reply With Quote
  #4  
Old 04-28-2016, 10:12 AM
wirejock's Avatar
wirejock wirejock is offline
 
Join Date: Oct 2005
Location: Estes Park, CO
Posts: 2,903
Default Bend

Quote:
Originally Posted by tsw94r View Post
Thanks Bill,

I appreciate the tips. It sounds like there really isn't a profile to go by at least in the plans.
There's some info in Chapter 5. Vans is pretty specific about getting a straight, flat surface up to the bend. I believe the radius is also called out. I used a dowell inside the bend then fine tuned the final bend without it.
__________________
Larry Larson
Estes Park, CO
http://wirejockrv7a.blogspot.com
wirejock at yahoo dot com
Donated 12/01/2017. Plus a little extra.
RV-7A #73391, N511RV reserved (1,800+ hours)
HS SB, empennage, tanks, wings, fuse, working finishing kit
Disclaimer
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
  #5  
Old 04-28-2016, 10:59 AM
tsw94r tsw94r is offline
 
Join Date: Apr 2016
Location: Monroe, Ga
Posts: 8
Default

Hi Larry,

I have read and reread the manual and plans, but can't find any reference regarding the radius of the bend. Section 5 does a good job of explaining how to make the bend, but the manual refers you to the plans for the bend profile.

I haven't started the bend yet, but I'm surprised that you would have the room for a dowel or did you just use it initially to keep the radius from getting too small?
__________________
Tom Wormsley
Slow Build RV-7, 3rd build, Emp 80%, Wings kit in shop
D73
Reply With Quote
  #6  
Old 04-28-2016, 01:11 PM
bret's Avatar
bret bret is offline
 
Join Date: Feb 2010
Location: Gardnerville Nv.
Posts: 2,763
Default

I used an 1/8" welding rod.
__________________
7A Slider, EFII Angle 360, CS, SJ.
2018 gladly supported
Reply With Quote
  #7  
Old 04-28-2016, 01:12 PM
bret's Avatar
bret bret is offline
 
Join Date: Feb 2010
Location: Gardnerville Nv.
Posts: 2,763
Default

or was it 1/16" have to go back and look at my log
__________________
7A Slider, EFII Angle 360, CS, SJ.
2018 gladly supported
Reply With Quote
  #8  
Old 04-28-2016, 02:53 PM
wirejock's Avatar
wirejock wirejock is offline
 
Join Date: Oct 2005
Location: Estes Park, CO
Posts: 2,903
Default Doh!

Quote:
Originally Posted by tsw94r View Post
Hi Larry,

I have read and reread the manual and plans, but can't find any reference regarding the radius of the bend. Section 5 does a good job of explaining how to make the bend, but the manual refers you to the plans for the bend profile.

I haven't started the bend yet, but I'm surprised that you would have the room for a dowel or did you just use it initially to keep the radius from getting too small?
I knew you would call me out!
Sorry, I can't find it. Maybe it was a VAF tip, but according to my log, I used a 3/16" dowel.
I used a strip of Gorilla tape to keep it from slipping out. After the initial squeeze, it was removed to allow the skins to bend past the final dimension. They reflex so you actually end up bending slightly more than the final angle. The biggest problem is the reflex on the bending jig. Even 2x6 will bend in the middle. I used at least 5 huge door hinges on mine.
__________________
Larry Larson
Estes Park, CO
http://wirejockrv7a.blogspot.com
wirejock at yahoo dot com
Donated 12/01/2017. Plus a little extra.
RV-7A #73391, N511RV reserved (1,800+ hours)
HS SB, empennage, tanks, wings, fuse, working finishing kit
Disclaimer
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
  #9  
Old 04-28-2016, 06:10 PM
hayabusa hayabusa is offline
 
Join Date: Feb 2011
Location: Brisbane, Australia
Posts: 37
Default

Now is good time for some forward thinking. Check this thread and anything else you can find on the subject of elevator misalignment or twist.
http://www.vansairforce.com/communit...ad.php?t=96921
Any amount of twist in the elevators will not necessarily become apparent to you if you simply follow the plans. What you will end up with is the elevators in trail as per the balance horn positions relative to the stab, you`ll drill the steel control horns off to the control rod as per the manual, but the inboard trailing edges of the elevators will be off quite a bit and it won`t even be mentioned in the plans.
You need to devise a jigging method to ensure the left and right elevators are a matched pair.
The twist can start being built in from the bend in the trailing edge if it is slightly off.
Reply With Quote
  #10  
Old 04-28-2016, 06:22 PM
wirejock's Avatar
wirejock wirejock is offline
 
Join Date: Oct 2005
Location: Estes Park, CO
Posts: 2,903
Default Jig

Quote:
Originally Posted by hayabusa View Post
Now is good time for some forward thinking. Check this thread and anything else you can find on the subject of elevator misalignment or twist.
http://www.vansairforce.com/communit...ad.php?t=96921
Any amount of twist in the elevators will not necessarily become apparent to you if you simply follow the plans. What you will end up with is the elevators in trail as per the balance horn positions relative to the stab, you`ll drill the steel control horns off to the control rod as per the manual, but the inboard trailing edges of the elevators will be off quite a bit and it won`t even be mentioned in the plans.
You need to devise a jigging method to ensure the left and right elevators are a matched pair.
The twist can start being built in from the bend in the trailing edge if it is slightly off.
Good point. I made a jig.
Hopefully they're straight. Guess I'll find out eventually.
Two pieces of melamine.
2 each 12"x 24"
1 each 6" x 36"
4 each studs 1/2 wood thread, 1/2 sheet metal thread
4 each wing nuts matching the sheet metal thread
Trace the end rib on one end piece aligned with the center line and more than 6" away from one end.
Clamp the two together.
Cut the "V"
Drill two holes evenly spaced along the 6" line.
Disassemble.
Place the three pieces on the bench.
Match drill the 6" brace through the ends.
Screw the four studs in the holes in the 6" brace.
Slide the uprights over the studs and install a wing nut on each.
One jig done.
Assemble the elevator in the jig.
Hang two plumb bobs from each end.
Shim the bottom of the jig till the bobs are perfect and it's square and straight.
__________________
Larry Larson
Estes Park, CO
http://wirejockrv7a.blogspot.com
wirejock at yahoo dot com
Donated 12/01/2017. Plus a little extra.
RV-7A #73391, N511RV reserved (1,800+ hours)
HS SB, empennage, tanks, wings, fuse, working finishing kit
Disclaimer
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.

Last edited by wirejock : 04-28-2016 at 06:25 PM.
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 07:48 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.