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Old 11-29-2021, 10:31 AM
Ralph Inkster Ralph Inkster is offline
 
Join Date: Feb 2008
Location: Calgary, Alberta
Posts: 1,793
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Good point Mike. You must have seen this issue (too) many times to prompt you to post it to this forum!


Quote:
Originally Posted by RV7A Flyer View Post
From the Construction Manual, in the section on building the ailerons:
Quote:
The bent skins must be straight up to the radius and the radius must be between 3/32” to 1/8”. Match the degree of bend to the full size end view drawings. The upper and lower skin should just touch the spar when placed in position.
It should be noted to not make the TE bend any tighter than the radius measurements above. Minimum sheet metal bend radius allowances assure that stress cracking does not develop in the bend. I came across one elevator that had been over bent & cracked in some places, and had to re-skin the unit.

The manual describes a bending fixture to use during construction. I found this good for the initial bend of the TE, but later after riveting, to finish off with a hand seamer as Mike described. Specifically a vice grip style hand seamer that can be adjusted to gradually pinch in the TE radius to a consistent radius. The other trick I use with the vice grip hand seamer is to lay a towel folded 3 layers thick inside the jaw to protect the seamer from making pinch marks at the ends of the jaw all along the TE.
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Ralph
built a few RVs, rebuilt a few more, hot rodded more, & maintained/updated a big bunch more

Last edited by Ralph Inkster : 11-29-2021 at 10:33 AM.
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