spaceflightmeow
Active Member
Preparing to dimple my wing ribs, I decided to test whether I could tell the difference when tank dies were used to dimple the substructure.
I drilled two test sheets, drilled #40, dimpled with DRDT2, and backriveted AD3-3.5. Top piece is .032" (such as inboard wing skins), bottom is .025" (main ribs).
Top test piece: standard dimple die top, tank die bottom (Cleaveland die, 0.007" deeper than flush).
Bottom test piece: standard dimple die top and bottom
In the top piece, there is no visible gap between the skins between the two rivets. In the bottom piece, there is a slight gap. Conclusion: tank dies for substructure produce tighter nesting dimples. I'll be using these for dimpling substructure.
Van's manual section 5.5 says to machine countersink 0.007" deeper than flush to accept a dimpled skin. So it would make sense that you would want to dimple the substructure 0.007" deeper as well.
EDIT: Looking at this again, I underdimpled slightly.
I drilled two test sheets, drilled #40, dimpled with DRDT2, and backriveted AD3-3.5. Top piece is .032" (such as inboard wing skins), bottom is .025" (main ribs).
Top test piece: standard dimple die top, tank die bottom (Cleaveland die, 0.007" deeper than flush).
Bottom test piece: standard dimple die top and bottom
![cKWeYid.jpg](/proxy.php?image=http%3A%2F%2Fi.imgur.com%2FcKWeYid.jpg&hash=30e760ace31ab7a4590ffd4229de3254)
In the top piece, there is no visible gap between the skins between the two rivets. In the bottom piece, there is a slight gap. Conclusion: tank dies for substructure produce tighter nesting dimples. I'll be using these for dimpling substructure.
Van's manual section 5.5 says to machine countersink 0.007" deeper than flush to accept a dimpled skin. So it would make sense that you would want to dimple the substructure 0.007" deeper as well.
EDIT: Looking at this again, I underdimpled slightly.
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