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Balance Control Surfaces

edclee

Well Known Member
Patron
I am making a new rudder and elevator for my 9A and since I did not make the aircraft originally, I have no experience with the balancing procedure. I see nothing in the plans regarding this other than simply mount the provided balance weight and go with it.

When I built my two Sonexes the plans were specific about balancing the surfaces and I did. From my experience over the years, balance needed to be checked even after painting. I did some research of past posts on this and consensus is that it is not necessary. Greg Hughes even responded to one post saying that it was not necessary just mount the weight per plans and Bob's Your Uncle. Right now I have the rudder hanging horizontally from the Hiem Joints and it is definitely heavier by a bunch at the trailing edge.

Can anyone provide more light on this subject? Any Aeronautical Design Engineers out there? :confused:
 
I am making a new rudder and elevator for my 9A and since I did not make the aircraft originally, I have no experience with the balancing procedure. I see nothing in the plans regarding this other than simply mount the provided balance weight and go with it.

SNIP.

This is exactly what you want to do. Years ago Van’s educated me on my question about there not be enough weight. I was told, in clear terms, static balance is not the objective.

Stay with the plans.

Carl
 
This is exactly what you want to do. Years ago Van’s educated me on my question about there not be enough weight. I was told, in clear terms, static balance is not the objective.

Stay with the plans.

Carl

Thanks for the response. I had come to that conclusion...I just wanted to be sure.
Ed
 
Greg Hughes even responded to one post saying that it was not necessary just mount the weight per plans and Bob's Your Uncle.

SPECIFICALLY FOR THE RUDDER: Using the weight as provided in the kit ensures proper margin against flutter. Installing the weight per plans and as-provided, without modifying it, is the correct way to address this.

The elevators need to be balanced.
 
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Greg
Not challenging anything…..just asking a question. On my 14 the right elevator was balanced neutral using the supplied weight cut to the dimensions in the plans. The left elevator with the pitch trim servo installed was aft heavy. I added about 200 grams of lead to the horn to get it to balance the same as the other side. Did this add “extra goodness” or was it unnecessary?
 
Using the weight as provided in the kit ensures proper margin against flutter. Installing the weight per plans and as-provided, without modifying it, is the correct way to address this.

Huh?!

Are you just talking about the rudder or also the elevators? It appears from the wording of the original post that the need (or lack thereof) to balance the elevators is also in play here.

Ken Scott specifically told me not only to balance the elevators, but to do so individually, drill as much weight out of the lead weight as necessary to get each one to line up with the horizontal stabilizer when the a/c was in level attitude.
 
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Huh?!

It's important to clarify whether we are simply talking about the rudder or also the elevators. It appears from the original post that the need to balance the elevators are also in play here.

Ken Scott specifically told me not only to balance the elevators, but to do so individually, drill as much weight out of the lead weight as necessary to get each one to line up with the horizontal stabilizer when the a/c was in level attitude.

Sorry - my comment was specifically related to the rudder. Elevators need to be balanced. I will edit to reflect that.
 
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Curious

SPECIFICALLY FOR THE RUDDER: Using the weight as provided in the kit ensures proper margin against flutter. Installing the weight per plans and as-provided, without modifying it, is the correct way to address this.

The elevators need to be balanced.

Just an academic question, why is not the rudder fully mass balanced too? I thought it theoretically should have more nose weight so that the rudder's CG is forward of the hinge line.
 
Also following this. I have a cosmetic issue on the right elevator lower trailing edge skin near the closeout tab. Vans support said I could use filler to fix the problem before paint as long as it didn't exceed the values in the attached table.

How do you accurately measure trailing edge heavy in in-lbs? Should RV-10 elevators be slightly tail heavy, neutral, or nose heavy, and if so by how much?
 

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Also following this. I have a cosmetic issue on the right elevator lower trailing edge skin near the closeout tab. Vans support said I could use filler to fix the problem before paint as long as it didn't exceed the values in the attached table.

How do you accurately measure trailing edge heavy in in-lbs? Should RV-10 elevators be slightly tail heavy, neutral, or nose heavy, and if so by how much?

An easy way to assess the in-lbs of the elevator trailing edge is to put a digital scale under a point along the trailing edge to hold the elevator neutral. Note the weight in lbs. Measure the perpendicular distance between the weighing point and the hinge line, in inches. Multiply the weight (lbs) by the measured inches, this gives you the in-lbs value.

Sorry I don't know the answer to the second question but would assume it should be neutral or slightly tail heavy (within the tabled limits), but not nose heavy.
 
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Also following this. I have a cosmetic issue on the right elevator lower trailing edge skin near the closeout tab. Vans support said I could use filler to fix the problem before paint as long as it didn't exceed the values in the attached table.

How do you accurately measure trailing edge heavy in in-lbs? Should RV-10 elevators be slightly tail heavy, neutral, or nose heavy, and if so by how much?

Is the attached table for the Rv-10 only? Is anyone aware of published specs for the -14?
 
Is the attached table for the Rv-10 only? Is anyone aware of published specs for the -14?

Vans pointed me to the PDF called "RV-10 Manual - Main.pdf." The table was on page 2. Maybe something similar exists for the -14.
 
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