Tail tips tips

[Bryan Cotton]

Here is a view of the Waiex tip in place. Easy to transfer holes when they are on top!

[Bryan Cotton]

I did notice that the trailing edge of the tip sticks past the ruddervator. I think I will trim the edge that goes against the rib. Because of the sweep of the leading edge that will move the tip forward.

[Rynoth]

Bryan, looks good! I did mine awhile ago, and trimmed off that little 1/4" strip that sticks out aft of the skin. I finished my ruddervators last night and upon installation realized that the little strip is actually to fill the small gap outboard of the end of the piano hinge. Oops. Aesthetic detail that makes it all my own!

[Bryan Cotton]

Ryan (or anybody),
I could trim the 1/4" off the back, or I can make the tip shorter, i.e. less span. That will pull the trailing edge in because of the taper of the leading edge. Anybody have thoughts on which way is better? The only downside of trimming like you did is you have to glue it back together. The downside of my proposed method is a lot more cutting.

[Bryan Cotton]

So much for paralysis by analysis - I figured out the tips need to be 11/16" shorter to make up the 1/4" in the trailing edge. I marked it up and cut it out. Pictures show the shortness and change in length.

[Darick]

On a related matter, does the fiberglass tend to crack at the rivets due to the small localized stress due the rivet? Has anyone used something like a washer to spread out the pressure of the rivets on the tip rib?
Darick

[Bryan Cotton]

Darick,
I have seen a lot of glass riveted to sheetmetal and no worries about cracking.

[Darick]

Ok. Thanks.

[Rynoth]

On a related matter, does the fiberglass tend to crack at the rivets due to the small localized stress due the rivet? Has anyone used something like a washer to spread out the pressure of the rivets on the tip rib?
Darick

Without directly answering your question, I wanted to pass on some fiberglass riveting information I received from Kerry at Sonex.

Me: "The plans call for normal CCP-42 rivets to attach fiberglass wingtips, I'm worried that this might be too much concentrated pressure on the fiberglass holes on the shop end of the rivet, any issues/suggestions for this?"

Kerry: "You can use aluminum rivets on the wingtips, as they are non-structural, but not on the tail tips. "

Me: "Any issues/concerns on using small aluminum washers under the rivet heads when the fiberglass is the outer layer? "

Kerry: "No washers are needed under any rivets for the fiberglass. The parts can be installed as shown in the plans."

Me: "Is there a particular type or brand of fiberglass filler you recommend to use with the fiberglass in the kits?"

Kerry: "Any off-the-shelf fiberglass repair kit can be used on our fiberglass parts."


I'd like to note in this that the only concession he made versus the plans is using aluminum rivets on the main wing tips (aluminum rivets being weaker and subjecting the fiberglass to less pressure, if you're worried about that sort of thing.) The tail tips, on the other hand, are structural and subjected to airflow and need to have the normal ccp-42 rivets as called for in the plans.

[Bryan Cotton]

I have set solid rivets in fiberglass too. I think this is harder on it than pops. I did my buddy's RV7 wingtips when I was stuck in Florida once.