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We mark the position of the new aileron ribs (that will support the mass balance arm)...
Note that the 13 mm. block under the outboard end of the aileron shown above is for the built-in aileron twist.
We lift up the skin and insert the ribs, and drill them into position (through the pilot holes):
Steve lays out the balance arm (square tube) between the ribs...
...and drills it into position.
Now, Roger marks the position of the balance arm where it will go through the aileron skin:
and drills through the skin and trims the opening to fit the square tube as marked.
We then insert the assembly into the aileron:
The two new aileron ribs bolt together sandwiching the balance arm:
We rivet the aileron ribs in place and re-rivet the top aileron skin:
We use mild steel plates as the weights for the needed balance:
We clean them up and deburr them:
...and bolt them to the end of the balance arm:
The balance aileron assembly (outside of the wing):
With the balanced aileron assembly complete, we drill and cut out the opening in the rear channel of the wing where the mass balance arm will pass through (here we use a nibbler to cut out the opening):
We then position the aileron to the wing (we slide the balance arm through the above opening with the steel balance weights removed):
A view of the inside of the outboard (left) wing where the balance arm enters through the rear channel opening:
View from the side (end of the left wing):
Here Caleb checks the angle and verifies that the aileron balances with the correct amount of counterbalance on the balance arm:
View from the side (end of the right wing):
The balance weights on our mail room scale: 1 lb. and 3.8 oz. (560 grams). This was the required balance amount for the right aileron.
To obtain a perfect balance, the number of installed steel plates can be adjusted, as well as their size...
The installed balance arm with the balance weight (primed).
We also added the "skin protection plates" as prescribed by the LAA Balanced Aileron drawing.
The top "skin protection plate" over the balance weights: