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  #1  
Old 09-21-2021, 11:19 AM
JeremyL JeremyL is offline
 
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Location: Maurertown,Virginia
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Default Thoughts on reinforcement plates!?? Discussion

So as I am assembling my elevators, I noticed the area behind where the elevator control horn doesn’t have a reinforcement plate. Thoughts/discussion on making some reinforcement plates and putting them here to help the load? Now I’m no engineer but it seems like that may be a decent spot for extra reinforcement to prevent future issues. All comments, thoughts welcome…
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  #2  
Old 09-21-2021, 11:21 AM
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Sam Buchanan Sam Buchanan is offline
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I'm not aware of any "issues" that have shown the need for reinforcement.
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  #3  
Old 09-21-2021, 11:52 AM
John Tierney John Tierney is online now
 
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I wouldn't add extra weight to the tail. The -7 elevator cracks noted in SB 14-02-05 were found at the rod end hinge points, not the horns.
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  #4  
Old 09-21-2021, 12:05 PM
JeremyL JeremyL is offline
 
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I haven’t seen any issues yet either. Also do you think the few extra grams/ounces would be a huge difference to the tail?
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  #5  
Old 09-21-2021, 12:10 PM
rocketman1988 rocketman1988 is offline
 
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Default Extra weight

Can’t say for sure in this case but yes, a few extra ounces/grams can have an effect. On a control surface, I would follow the plans…
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  #6  
Old 09-21-2021, 12:13 PM
David Paule David Paule is offline
 
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I weigh most things that I add to the plane in grams and try to minimize them. If you want a light airplane, we've got to pay attention to things like that.

Also, it might be helpful to talk with a real structural engineer and ask that person to show you some examples of airplane load paths. In this case, there is an ample load path built in.

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Old 09-21-2021, 12:39 PM
alpinelakespilot2000 alpinelakespilot2000 is online now
 
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Be careful. A solution in search of a (non-existent) problem often leads to (real) problem.
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  #8  
Old 09-21-2021, 01:10 PM
JeremyL JeremyL is offline
 
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Interesting points of view, and yes the load is dispersed via the long parts of the horn. Just spitballing for conversation, I’m almost certainly going to follow the plans in this area. I should have been an engineer haha
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  #9  
Old 09-21-2021, 06:35 PM
BillSchlatterer BillSchlatterer is offline
 
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Default There is a plate

The skin in a monocoupe design carries a lot of the various loads. It is effectively the plate you are considering. It would only need reinforcing if their were buckling or stress points specific to that area.

Van is an aeronautical engineer with a stellar record and there are 10,000+ flying. The thing that slows many many builders down is trying to improve a design and add "improvements" where there is no need.

If you aren't capable (and I'm not for sure ) of doing a true structural load test or have builder/designer knowledge that exceeds Vans group, you should probably work hard on building the airplane specifically to the plans. That is the quickest and safest way to get a kit in flyable form.

Just my .02 after building a couple and watching several get the "improvement" process where none were needed.

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  #10  
Old 09-21-2021, 09:32 PM
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Z-EDD Z-EDD is offline
 
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Quote:
Originally Posted by BillSchlatterer View Post
The skin in a monocoupe design carries a lot of the various loads. It is effectively the plate you are considering. It would only need reinforcing if their were buckling or stress points specific to that area.

Van is an aeronautical engineer with a stellar record and there are 10,000+ flying. The thing that slows many many builders down is trying to improve a design and add "improvements" where there is no need.

If you aren't capable (and I'm not for sure ) of doing a true structural load test or have builder/designer knowledge that exceeds Vans group, you should probably work hard on building the airplane specifically to the plans. That is the quickest and safest way to get a kit in flyable form.

Just my .02 after building a couple and watching several get the "improvement" process where none were needed.

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I think bill meant “monocoque”, and this is the key. The structure as pictured may seem flimsy, but add the skin and it becomes a rigid box, plenty strong.
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