Friday, July 18, 2014

Baggage Bulkhead Modification Work Continues

Forgot to mention in the last post that the F-1206G-R rib that the newly made angle will attach to has a slight skew from vertical. When over at Steffon’s fabrication shop bending the angle, I remembered that the baggage rib has a slight angle but did not remember which way it went so I purposely under bent the angle in the brake. As it turns out it actually needed to be bent slightly past 90 degrees … so quite a bit of time was spent putzing around tweaking the angle with seeming tools and a mallet to get it in the ball park. So builders inclined to do this mod should bend the angle to a little past 90 degrees.

After the angle was in the ball park it was then positioned onto the F-1206G-R baggage rib and drilled in place. The rivet holes really can’t be evenly spaced because there is a large flanged lightening hole and a tooling hole on the F-1206G-R baggage rib that infringe on the minimum edge clearances suggested for rivets … plus I did not want to drill into the flange the lightening hole has ridge around it. Long story short, care needs to be exercised when drilling the four rivet holes into the F-1206G-R baggage rib. Pilot holes were drilled into the angle and then it was clamped onto the F-1206G-R baggage rib and match drilled.
Drilling small pilot holes into the modification angle that will be used to match drill into the F-1206G-R baggage rib.
With the new modification angle clamped in position, the angle was match drilled into the F-1206G-R baggage rib.
New modification angle drilled and held in position on the F-1206G-R baggage rib with Clecos. The aforementioned flanges around the lightening holes can be clearly seen here

The F-1206E baggage floor was cut 3/8" towards the right side of the airplane from the center line of the existing mounting holes for the F-1206G-R baggage rib. Caution: Measure and make cut marks from the centerline of ALL THREE screw holes then draw a straight cut line connecting the three marks. The holes in my F-1206E have a small offset from front to rear … so measuring from the centerline of each hole and drawing a line will keep the cut parallel to the edge of the existing baggage rib. The idea here is to make the cut directly over the point where the new angle meets the F-1206G-R baggage rib.

Because the cut will get close to the existing mounting hole on the aft flange of what will become the left half of the F-1206E baggage floor, a small 5/16" offset was marked to the right side of the aircraft. Next the back edge or flange of the F-1206E was cut through on the band saw. Then the small offset line (approximately 3/8" long) was  scored using a Stanley razor blade knife to weaken the aluminum. Next the band saw was used to make the long cut up to the scored area. A slight amount of light bending caused the aluminum to separate at the score line.  After the F-1206E baggage floor was cut in two and deburred, the small piece that will reside under the fuel tank was set in place and screwed in position so it could be match drilled into the new mounting angle.
Drilling pilot holes through the F-1206E into the new angle for the three mounting holes. Looking closely at the left panel one can see the offset mentioned above.
Final drilling the three mounting holes to #19.

After the mounting holes for the right half of the F-1206E baggage floor were drilled, the #19 holes were dimpled for #8 flush screws ... plus holes were drilled and dimpled for K1100-8 nutplates. An additional nutplate was installed just to the right of the offset to offer support for the edge of the right F-1206E near the offset cut.
Using the pneumatic squeezer to install the new K1000-8 nutplate in the F-1207B bulkhead which will support the right half of the F-1206E baggage floor and the yet to be cut portion of the corrugated baggage bulkhead cover.
Dimpling the three new #19 mounting holes in the right half of the F-1206E for #8 screws.

After all the cutting drilling and dimpling the newly created left and right F-1206E baggage floors fit nicely. Next work session will focus on the baggage bulkhead cutout.
The newly separated left and right F-1206E baggage floors fit nicely together. My finger is pointing to the newly installed nutplate/mounting hole … the offset mentioned above can be clearly seen to the right of my finger after expanding the photo to full size.