HS-405 to HS-702 Flange Edge Distance

aeropunk · #1 01-01-2010, 08:22 AM

It looks like this has come up before, but I guess I just need to be reassured since I'm new at this.

While drilling the inboard (non-prepunched) section of the HS-702 front spar flange to the HS-801PP skin, I came upon a problem with the last hole, which goes through the 801, then the 702, then the top of the HS-405 flange. As you can see from the photos below, there isn't sufficient minimum edge distance on the 405 flange.

Per the plans, I pushed the 702 tightly against the front flange of the 405, and even drew a centerline on the 702 to make sure those distances were acceptable. But since the position of that top hole is set by the 801PP skin and the pre-formed 405, I don't think there's any way NOT to end up with this.

It looks like RVG8tor contacted Van's about this very problem and they said it was okay, since the "HS-405 rib flange has been slightly short ever since the first kit RV-4." I'm tempted to call myself unless the consensus from you guys is, "build on."

Thanks!

Mel · #2 01-01-2010, 08:54 AM

Build-on!...(Added words to make this stupid system work)

Mel · #3 01-01-2010, 10:19 AM

Whenever given the option between dimpling and machine countersinking, always dimple. Dimpling will almost always give a slightly stronger and more consistent joint.

mackd · #4 01-01-2010, 12:42 PM

I'm not sure there's ever been an RV built without this problem... Don't worry about it!

aeropunk · #5 01-01-2010, 01:22 PM

Thanks for the input, guys. I'm moving on ...

Mel · #6 01-01-2010, 02:22 PM

Quote:

Originally Posted by mackd

I'm not sure there's ever been an RV built without this problem...

Oh, there's been Lots of them. You seem to forget, when we built, we didn't get any holes. We put them where we wanted them.

DaAV8R · #7 01-01-2010, 10:56 PM

Quote:

Originally Posted by oceanbird

Hope you don?t mind if I steal this thread, sorry, but
I was never sure about what to do with that particular rivet,
and others that also go through 3 parts. What is the best way
to go?

a- Dimple all three parts.

b- Machine countersink the skin and leave the rest alone.

c- Machine countersink one of the underlying parts(rib?) and dimple
the others.

Thanks in advance for the advice.

oceanbird

I have been wondering about this also. I have been dimpling the top skin and countersinking the second ply and nothing in the third. Any comments from the more experienced builders?

Thanks

magiccarpet · #8 10-15-2013, 03:20 AM

Thank you for having posted your experience and comments on that issue,
I have just arrived there and figured, that my MED on the HS-405 (to HS-702) will be very minimum, if not sligthly too short.
I suppose I don't have to worry much about it and can start drilling

WingsOnWheels · #9 10-15-2013, 06:41 AM

Quote:

Originally Posted by DaAV8R

I have been wondering about this also. I have been dimpling the top skin and countersinking the second ply and nothing in the third. Any comments from the more experienced builders?

Thanks

In most cases, If the part is 0.040 or less, dimple it. Greater than 0.040 then countersink. If you have multiple layers, none greater than 0.040 then dimple them all unless the plans call out something different. If you have a stackup with multiple layers and one is too thick the dimple, countersink that thick layer and dimple eveything on top.