Monday, September 3, 2007

UCA riveting

Build hours: 157
Well, we finally get to complete assembly on some of these #!$ skins and bulkheads! Man, we've been doing this forever - isn't it done yet! Construction so far has always been hot, sometimes perplexing and once in a while just dang tiresome and frustrating. However, in the next few paragraphs, the plan comes together - who needs laser cut kits! Whoo-hoo!
The skeleton of UCA (refresher coarse for the slower readers - UCA = UltraCruiser "A") was further denuded as the last two skins, bulkheads and stringers were removed for riveting, deburring and trimming at the overlap. Additionally, the overlapping skin edge was inserted into the brake 1/8" and bent approx 3 degrees to create a tighter edge when riveted.
The skins had a lot of marking from skin oils and perspiration that was unattractive and could lead to surface corrosion on the 6061. Acetone or mineral spirits had no affect on the smudges. Some weak AlumiPrep (phosphoric acid etch normally followed by an Alodine treatment) on a sponge followed by generous rinsing was found to remove the smudges and return the aluminum to its originally bright state.
The E to F skin was wrapped and rejoined at the bottom stringer with clecoes and the top stringer was clecoed in place. E2 was riveted in followed by F and the stringers. The pieces were handled with cotton gloves during the riveting to avoid re-smudging the inside surfaces. Finally the three 1/4-28 nutplates were added at the appropriate E2 tabs.
Plan note:
F was not riveted where the tail wheel spring bracket will be and the top stringer was not riveted where the vertical stab lower rib will be added later.
Bulkhead E was put in place with a few clecoes and the stringers for the next section were riveted onto E. The D to E skin was rejoined on the bottom stringer and the top stringer was added. Bulkhead E was riveted in along with the stringers. Some denting or wrinkling as the rivets pull the skins to the bulkheads is inevitable at the change of angles on the skins.
Some more of the beam was removed (with joy!) and the D to F assembly was hung on the D bulkhead.
UCB was denuded so that we could get the original C skins back for UCA. C skins for UCB
(UCB = UltraCruiser "B" in case your still not catching on to the naming scheme) were cut from the originals. The original skins were repositioned on UCA ready to be drilled up to 1/8" holes.
At this point, there really should be a picture but I'm too pooped to walk back out to the shop!

1 comment:

  1. Southern person: What ya'll mean by UCA and UCB?

    Smart airplane builder: You choose -
    A) Unuther Cessna A or B
    B) UroCoupe A or B
    C) UltraCruiser A or B