What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Thoughts on reinforcement plates!?? Discussion

JeremyL

Well Known Member
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…
 

Attachments

  • 905FB068-6DF9-49C2-8AC2-DD986883A1BC.jpg
    905FB068-6DF9-49C2-8AC2-DD986883A1BC.jpg
    306.9 KB · Views: 259
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.
 
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?
 
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…
 
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.

Dave
 
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
 
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" :rolleyes: where there is no need.

If you aren't capable (and I'm not for sure :eek: ) 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.

Awesome airplanes...:)
 
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" :rolleyes: where there is no need.

If you aren't capable (and I'm not for sure :eek: ) 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.

Awesome airplanes...:)

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.
 
This is why I asked these random questions….. I learn so much and soak it up like a sponge. Ideas like this, I don’t let slow me down. I have full faith in the design, but my brain wants the additional knowledge.
 
Back
Top