[N546RV]

OK, so I did some searching on this, and I've found a lot of information on edge distance issues when drilling HS-405 to HS-701 and HS-810/814.

That, however, is not what I'm asking about. Thanks to lots of reading beforehand, I had no trouble making those holes and keeping proper edge distance. I was not, however, so fortunate when drilling HS-405 to the skins.

On both of stabs, top and bottom of the ribs, I have the same problem: the forwardmost hole is a touch under MED. Edge distance on all the holes is about the same, maybe a touch shy of 5/32 from center, which works out to 1.67D.

What gets me is that I don't see any way for this to not have happened. Obviously I'm using prepunched holes in the skin for drill guides, and the position of the rib isn't exactly variable; the only way to move it forward and thus increase edge distance would be for it to not be clamped to the rear spar channel.

Anyways, the advice I see concerning MED issues in the front flange amounts to "build on"...does that apply here as well? I figure worst case, I could drop another rivet to shore things up, and it would be pretty nonobvious.

Thoughts?

 

[larrynew]

When measuring for edge distance or rivet quality, I use the Mil Spec (Military Specification) document that Van's provides on his website:

http://www.vansaircraft.com/public/Specs.htm

There are different edge distances for different holes and rivets. For example, the edge distance for a non-flush rivet, plain hole, 1/8 rivet is .219 but for a flush rivet, countersunk hole, 1/8 rivet it's .281. Quite a difference from the "rule of thumb" .250 (2 times diameter).

 

[SilverEagle2]

According to my math...1.67D is spot on the Min ED for a dimpled CS 3/32 rivet of 0.156" per the document link above.

It is common to have occur at this location.

Build on. (Van's told me the same when I asked about my HS-405)

 

[N546RV]

According to my math...1.67D is spot on the Min ED for a dimpled CS 3/32 rivet of 0.156" per the document link above.

It is common to have occur at this location.

Build on. (Van's told me the same when I asked about my HS-405)

Agreed. My measurements, and Larry's info, indeed point conclusively to "build on!"

Thanks for the info, Larry. I should get familiar with this data; clearly there's a lot more to know than just "two diameters."

 

[Flyin'Bryan]

Same problem -same answer

I called Vans to discuss it with them at the time that I ran into this issue. Build on was the answer. Glad to see you are pushing through all the hard parts.

 

[aeropunk]

As you mentioned, there's simply no way NOT to end up with this. It's been a known issue for awhile.

http://www.vansairforce.com/community/showthread.php?p=391788

 

[N546RV]

As you mentioned, there's simply no way NOT to end up with this. It's been a known issue for awhile.

http://www.vansairforce.com/community/showthread.php?p=391788

What's amusing to me is that I looked at that exact thread before starting this one. Problem was that, until this moment, I'd been misinterpreting the pictures and thought it was showing a hole in the front flange of HS-405. Of course, now I look at it and realize that it contains the exact guidance I was looking for...

 

[xblueh2o]

I am right at this point this afternoon.
I have everything clamped in place but not yet drilled and it looks like I will have roughly the same dimensions after drilling. Came home to do a little work, have lunch and research this issue. Glad to know it is known and it is a build on.