The afternoon was spent creating crater after crater along both flanges of each rear wing spar and during a break ended up watching a guy breaking the sound barrier during a freefall after he jumped out of a pod from 128,050 feet at the edge of outer space. Fortunately, the guy’s parachute opened and he landed safely … and here I am worrying about making perfect dimples in the RV-12’s rear wing spars.
In an effort to save my hand from holding the
heavy pneumatic squeezer while making a bazillion dimples, I was able to work
out a way to rest the squeezer on the workbench and make the dimples without
holding the heavy squeezer. Unfortunately, the flanges on the spars are not 90
degrees (if memory serves me they were 85 degrees) so it required placing wedges
under the spar to get the angle of the spar to match up with the dimple die at
90 degrees. Once again a piece of metal bent to 90 degrees was attached to the
squeezer yoke gave me a visual indication that the squeezer was being held perpendicular
to the spar before setting the dimple into the metal.
Using the pneumatic squeezer to dimple the rear
spars with 120 degree dimple dies necessary for flush pop rivets. Wedges under
the spar adjusted the angle of the spar to match the squeezer and the 90 degree
guide clamped on the squeezer’s yoke aided in keeping the squeezer perpendicular
to the rivet holes (paper towel used to eliminate reflections for the camera).
Both rear spars dimpled and ready for primer.
After completing the dimpling of both rear spars,
they are now awaiting priming before assembly begins, so decided it was time to
move on and address the RV-12's wing ribs. There are a pile of ribs and they will all need
to be straightened by fluting because most all of them are quite bowed which will
need to be addressed ... I see hours of fluting on the horizon.
The bow in the ribs can easily be seen here …
there are lots of ribs to straighten, well over 50 so I’ll be busy for a while.
A finger easily fits under most of the ribs.