|
-
POSTING RULES

-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|

04-14-2014, 06:58 AM
|
|
|
|
Join Date: Jan 2005
Location: Ontario, Canada
Posts: 1,544
|
|
elevator trim tab cutout bends
The left elevator skins have a close out tab that needs to be bent, one down the other up, to form a lapped joint. The plans call for the use of a piece of wood sandwiching the skin to a work bench. Then using another piece of wood to bend it down. I am sure this works but I present a simple alternative that is accurate and repeatable. I made a simple "brake" using some scrap angle.
I cut the short angle the same length as the tab to be bent. The "bed" angle, the angle that the tab bends around has the sharp edge filed off to give a nice radius. On the picture you can see how the bed angle has a round radius. I left the plastic on to limit any marking of the material during the process. Mark both sheets with a line as documented in the plans. Put a line on top and bottom of both sheets and then lay the sheets together to varify that the lines are in the exact same locations. Mark on the sheets which tab bends bends up. On the first sheet, the one with the predrilled hole, clamp the " bed" angle so that the line is just visible.The top and bottom fixed angles are clamped to the line with the bed angle back just enough to take into account the thickness of the material to be bend. Then simply bend the tab to 90 degrees. Hand pressure was all that is needed. Of course you should practise on some scraps before trying the real bend!
For the bend on the next sheet simple move the bed angle back 1/32" from the line and make the bend. This allows for the overlap of the tabs. 1/32" is real close to .032 and I just used a scrap of material between the line and the bed to get the proper distance. The result is a perfect lap joint

__________________
Tom Martin RV1 pilot 4.6hours!
CPL & IFR rated
EVO F1 Rocket 1000 hours,
2010 SARL Rocket 100 race, average speed of 238.6 knots/274.6mph
RV4, RV7, RV10, two HRIIs and five F1 Rockets
RV14 Tail dragger
Fairlea Field
St.Thomas, Ontario Canada, CYQS
fairleafield@gmail.com
|

04-14-2014, 11:01 AM
|
|
|
|
Join Date: Apr 2010
Location: Chicago, IL
Posts: 356
|
|
Tom,
That is a nice little brake.
I must confess however that having built my Sonex with only the 'hit it with a hammer on the edge of a table method' that is how I did these bends. Practice on all the Sonex little bends led to a very nice job for me.
For people with less confidence in my method yours looks nice and simple.
|

04-14-2014, 12:05 PM
|
|
|
|
Join Date: Dec 2006
Location: New Orleans, LA
Posts: 474
|
|
Elevator Trim Tabs
Hey Tom,
Wish you would have posted that last Friday. Saturday I bent the tabs and today called Van's to ask if I needed to replace the skins. The bend went too far back into the skin and it adds stress to the skin by the relief areas. The suggestion from Van's was, it's no big deal, just use a small file and take the stress out of the area. Hope that works, although it won't look nearly as nice as yours. Still can't figure out how to get smaller pictures posted here. I'm using TinyPic to upload them like they suggest.

__________________
Stoney
First RV-14 Flight 04/17/2016
Serial #140087, N214SW - Sold
|

04-14-2014, 12:47 PM
|
 |
|
|
Join Date: Jan 2008
Location: Granbury, TX
Posts: 543
|
|
Maybe it sounds like whining, but I really wish Vans would get rid of bending tabs altogether and supply small end ribs....
Even if they cost $15 or more each, I'd be money ahead in all the screwed up trim tab skins I've had to reorder while building my 7A and 10.
__________________
Jason Tremble
RV-7A (Flying and Sold)
RV-10 in process (@#$$%# Cabin Top & Doors)
Paid for 2020
|

04-14-2014, 07:44 PM
|
|
|
|
Join Date: Jan 2005
Location: Cincinnati, OH
Posts: 1,558
|
|
.....or you could just make your own little end rib out of aluminum (.016), blue foam and glass cloth(easiest), or balsa wood - covered with a layer of glass (second easiest). I've done the aluminum one and the foam/glass, and both have held up for a long time. No cracks or other issues. If you're picky about minutia, the glass method (either one) looks a little better - no lines or breaks in the paint as if it's a solid piece. Total time fabricating this part (not the aluminum one) is no more than 20 minutes - including sanding after epoxy cure. Works fine - lasts a long time....
__________________
SH
RV6/2001 built/sold 2005
RV8 Fastback/2008 built/sold 2015
RV4/bought 2016/sold/2017
RV8/2018 built/Sold(sadly)
RV4/bought 2019 Flying
Cincinnati, OH/KHAO
JAN2020
|

04-15-2014, 04:53 AM
|
 |
|
|
Join Date: Apr 2012
Location: Tampa, FL
Posts: 310
|
|
Quote:
Originally Posted by jswareiv
Still can't figure out how to get smaller pictures posted here. I'm using TinyPic to upload them like they suggest.
|
They give you the option to resize the pic, choose the Message Board size of 640x480.
__________________
Tom B
Tampa, FL
EAA - Tampa Exec Airport
|

04-15-2014, 08:00 AM
|
|
|
|
Join Date: Dec 2006
Location: New Orleans, LA
Posts: 474
|
|
Quote:
Originally Posted by propsync
They give you the option to resize the pic, choose the Message Board size of 640x480.
|
Thanks Tom, will do.
__________________
Stoney
First RV-14 Flight 04/17/2016
Serial #140087, N214SW - Sold
|

04-15-2014, 04:55 PM
|
|
|
|
Join Date: Jan 2005
Location: Ontario, Canada
Posts: 1,544
|
|
Stoney
I had a look at the pictures you posted. As others have suggested you could just make a rib to replace these tabs. Before doing that I might suggest a possible save.
Take a piece of angle and firmly clamp it to your back riveting plate. Place your skin on the back riveting plate with the tab up against this angle. Now take another piece of angle and place it on the sheet up against the tab. Make sure to round off and smooth the sharp corner of the angle. This will leave you with a sandwich, two angles with your tab between them.
Take a piece of hard wood, brick chisel, etc and place it on the inside of the angle.
This is the fun part, take a hammer and firmly strike the inside of the angle. This has the effect of pushing the two angles, and your tab together. Have a look and see if the tab angle has a better shape, if not whack it again.
You might just be able to save this tab. If not then make a rib and move on.
__________________
Tom Martin RV1 pilot 4.6hours!
CPL & IFR rated
EVO F1 Rocket 1000 hours,
2010 SARL Rocket 100 race, average speed of 238.6 knots/274.6mph
RV4, RV7, RV10, two HRIIs and five F1 Rockets
RV14 Tail dragger
Fairlea Field
St.Thomas, Ontario Canada, CYQS
fairleafield@gmail.com
|

03-29-2015, 08:52 AM
|
|
|
|
Join Date: Oct 2014
Location: Sebastian Fl X26
Posts: 81
|
|
Tom,
I made the mini-brake as you suggested ($9 for parts...) and it worked perfectly.
Thanks for posting helpful suggestions,
Dennis
__________________
Dennis Callaghan (X26)
- RV14 sn:140193 - first flight 12/19/2019
- 2000+ hours on my RV6! Sold (so sad...)
- donation 12/30/2019 * 2
|

09-17-2017, 10:16 AM
|
|
|
|
Join Date: Sep 2015
Location: Marion, IN
Posts: 231
|
|
I used Tom's technique to do my elevator close-outs and I am very pleased with the results. For what it's worth, I made a video of the process. Hope it helps!
https://youtu.be/-iZ3BpSMhn8
untitled_001.jpg by Ray Dosh, on Flickr
__________________
Ray Dosh
LJ45 driver
RV-14 QB #140212
Tail feathers finished
Tail cone in progress
2020 DUES PAID
Marion, IN MZZ
|
| Thread Tools |
Search this Thread |
|
|
|
| Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 01:53 AM.
|