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 Today's Posts

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 05-25-2011, 09:32 AM
RVGator RVGator is offline
 
Join Date: Aug 2010
Location: Gainesville Florida
Posts: 25
Default VS-808PP Countersink

I am attaching the 808PP doubler to the 803PP rear spar. After counter-sinking the 808 doubler I clecoed it to the 803PP spar to check the fit. It appears the doubler is standing a few thousandths above the spar. Notice the lack of a gap between the right lightening hole and the spar and the presence of a gap on the left hole.



I'm afraid to countersink any deeper before I get some advice. The countersink is already slightly deeper than the rivet itself. I expected that since it has to accept the dimpled spar. But I don't want to go any deeper until I check with the pros.
__________________
Dave
RV-7
Started Emp 1/12/11
Finished HS 5/6/11
Finished VS 5/27/11
Reply With Quote
  #2  
Old 05-25-2011, 10:05 AM
compren compren is offline
 
Join Date: Mar 2005
Posts: 78
Default I don't have my plans with me...

If you've already countersunk to the point where your rivet is sitting in correctly, then it's probably not your countersink causing the pieces not to mate. Typically, when I run into this problem, I find a hole that I missed during the deburring process and a burr is causing the part to not sit correctly.
Reply With Quote
  #3  
Old 05-25-2011, 10:59 AM
hendrik hendrik is offline
 
Join Date: Nov 2009
Location: Heidelberg, Germany
Posts: 182
Default

Check that you haven't underdimpled.

How deep are your countersinks, i.e. how many clicks beyond "rivet is flush"? IIRC I went about eight clicks further (.008").
__________________
Hendrik
Club-Libelle: flying
RV-8: on hold (new job , new home , no workshop (yet) )
Reply With Quote
  #4  
Old 05-25-2011, 11:20 AM
RVGator RVGator is offline
 
Join Date: Aug 2010
Location: Gainesville Florida
Posts: 25
Default Countersink is the same

I guess I'm lucky, I didn't count cliks but I eneded up .008" beyond flush as well.

I've carefully inspected for burrs and bad dimples. I dimpled with a pneumatic squeezer mounted in a vice so the dimples seem very consistent. I did notice that when I clecoed only the dimpled section (just the bottom rivets that are supposed to be flush), VS808 sat flatter - still not perfect- but better. Clecoing the rest of the doubler resulted in some lifting. The doubler does have a lengthwise bow in it. Also, the edges of the doubler where they extend past the spar flange appear nicely fitted. It's just around the lower 2 lightening holes that I have the concern.
__________________
Dave
RV-7
Started Emp 1/12/11
Finished HS 5/6/11
Finished VS 5/27/11
Reply With Quote
  #5  
Old 05-25-2011, 11:32 AM
Danny7 Danny7 is offline
 
Join Date: May 2008
Location: central oregon
Posts: 1,089
Default

do you still have the problem if you fill every single hole with a cleco?
__________________
nothing special here...
Reply With Quote
  #6  
Old 05-25-2011, 11:37 AM
Ron Simpkins Ron Simpkins is offline
 
Join Date: May 2010
Location: Damascus, Oregon
Posts: 19
Default

You probably have a burr trapped between the two parts.
Reply With Quote
  #7  
Old 05-25-2011, 03:33 PM
RVGator RVGator is offline
 
Join Date: Aug 2010
Location: Gainesville Florida
Posts: 25
Default Might be the spar web

I'm stumped. In this series of photos I add clecos to the spar and doubler.




With each pair of clecos the spar web separates further from the doubler






When I remove all but the end-most clecos, all falls nicely back into place.



Will this separation happen when I rivet? Is it the result of torquing from the cleco springs? The separation doesn't occur further up the spar.
__________________
Dave
RV-7
Started Emp 1/12/11
Finished HS 5/6/11
Finished VS 5/27/11

Last edited by RVGator : 05-25-2011 at 07:49 PM. Reason: New Info
Reply With Quote
  #8  
Old 05-26-2011, 08:12 AM
RVGator RVGator is offline
 
Join Date: Aug 2010
Location: Gainesville Florida
Posts: 25
Default Countersinks too deep?

Is it possible that my countersinks are too deep?
__________________
Dave
RV-7
Started Emp 1/12/11
Finished HS 5/6/11
Finished VS 5/27/11
Reply With Quote
  #9  
Old 05-26-2011, 08:20 AM
krw5927 krw5927 is offline
 
Join Date: Aug 2010
Location: Wichita, KS
Posts: 1,958
Default

What happens if you use a spring clamp or c-clamp (or similar) to clamp the parts together in addition to the clecos? If the gap goes away with a little more clamping pressure, then clamp them back together before you rivet and pound away.

My guess is the 808PP doubler is not perfectly flat and is contacting the 803PP spar at the edges where the clecos sit. You're seeing the apex of the slightly curved doubler causing a gap at the lightening holes.

Could that be what's going on?

To verify, you could turn the doubler over on the spar (so that the surface you see in the photos is then sitting against the spar). If the gap goes away then the doubler is slightly warped (of course now the gap should be at the edges, where the clecos are. Wouldn't surprise me the way these parts are stamped out.

Last edited by krw5927 : 05-26-2011 at 09:03 AM.
Reply With Quote
  #10  
Old 05-26-2011, 09:05 AM
RVGator RVGator is offline
 
Join Date: Aug 2010
Location: Gainesville Florida
Posts: 25
Default That's what I thought...

I tried that and it all fit perfectly.

I can squeeze the parts back together. But if I have cut my countersinks a few thousandths too deep will I have a weakpoint?

Vans emailed and said they saw nothing wrong with any of the fit. Unfortunately I've been unable to get a good picture to send.
__________________
Dave
RV-7
Started Emp 1/12/11
Finished HS 5/6/11
Finished VS 5/27/11
Reply With Quote
Reply



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 06:21 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.