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One of the "other" ones

Posted: Tue Jun 21, 2005 10:34 pm
by cjensen
Well I just got back from Oshkosh. I flew up there with a friend of mine who is building a Sonex. He is also writing a book on the Monnett family, and the company. Pretty neat stuff. I got a full tour of the facility, met John and Jeremy Monnett, and visted the museum again.

I have to say, though, that I am not a fan of the Sonex. Sleek airplane, but they are completely pop riveted together, exept the main spar. They say it's very strong, and I have seen the demo videos, but I just can't help but think how much stronger our RV's are using solid rivets.

Anyway, it's REALLY bare at OSH, but they are working hard preparing it for us! I CAN'T WAIT!!!!!!!!!! :)

Posted: Wed Jun 22, 2005 12:53 am
by Snap
im just wondering...if you got one and used flush rivets, what would the difference be in speed I wonder?

Couldn't be that hard.

C'mon, someone do it. chop chop!! :lol: :lol:

Use of pop rivets

Posted: Wed Jun 22, 2005 6:57 am
by jimrobinette
I have heard, but not confirmed, that the Murphy Moose is all pop rivets, or at least some form of blind rivets. Would be nice for building, but with the Moose, I don't think you are really concerned about speed!

Posted: Wed Jun 22, 2005 8:03 am
by Spike
I am not sure that I agree that an airplane assembled with "pop" rivets is all that much weaker than those assembled with solid rivets soley on that fact.

Most rivets are shear loaded correct? If so, in order for the difference between the shear strength of the rivet types to be a factor then everything else has to stand up first. That is to say that the metal does not fail around the rivets (ie correct edge distance, yadda yadda yadda) and that the structure itself is designed such that the rivets are the first things to go. I don't know if this would hold up for most designs that are done accordingly.

If you put "pop" rivets in an RV it very well may be weaker, but then it wasn't designed for them. But a design, such as the Sonex, that was intended to be assembled using them very well might be just as safe or strong. I definately would not count such an airplane as weaker or less safe soley on that fact.

-- Spike

Posted: Wed Jun 22, 2005 8:54 am
by cjensen
I agree, spike. It's probably more of a mental thing for me-I like solid rivets better. They just sound and look stronger. The demo videos that I've seen, one factory and one customer, show the airplane pulling 4-5 G's in loops and rolls, etc...So, I know they are strong in their design, and the contruction is pretty robust, I just can't get my mind around using some type of blind rivet for complete construction. Just an opinion, and it doesn't really matter since I'm not building a Sonex, but an RV!!! :mrgreen:

The trip was worth while just meeting John Monnett and getting a factory tour from him!! 8)

Posted: Wed Jun 22, 2005 4:37 pm
by jim_geo
UGHHH. It posted and I wasn't ready to post.

Posted: Wed Jun 22, 2005 4:42 pm
by jim_geo
I agree with you spike. However, at my last annual on the ol 152 the very first thing the A&P squawked was the carb heat mounting bracket that had been attached at some point in time with pop rivets to the hot air box. What was happening was simple wear and they (two of them) were wearing threw and almost ready to break. The bracket itself of course was pretty loose. Had one or both of the rivets actually broken the rivet parts could have been sucked up into the carb and run threw the engine. I guess we all can take away from my posting what we will but for me I'd rather use a solid rivet at least for the areas that I can get one bucked.

Posted: Wed Jun 22, 2005 5:56 pm
by Spike
Hmmm, interesting. I guess not seeing what the problem was the question I ask is that if this was a problem that would have not occured with solid rivets? And if that is the case, do we know that pop rivets were called for from the factory?

-- John

Posted: Wed Jun 22, 2005 8:23 pm
by svanarts
Don't forget that "pop" rivets come in different flavors. Cherry Max rivets are just as strong if not stronger than a regular aluminum rivet. The standard pop rivet that most A&P's hate are much weaker. A lot of times both types of rivet get lumped into the same "weak" category. I've watched a Murphy Rebel going together and there is NO WAY most of those rivets could be driven. The entire structure was engineered to be held together by pulled rivets. I believe the Sonex is the same. Way more rivets than our birds.