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Mistakes I Made! This is where I'm going to expose all my mistakes. I'm doing this so
that hopefully someone else can learn by my (bad) example rather than
learning by making mistakes themselves. Actually, what this will
really do is just allow you to make up your own, unique, mistakes!
Mis-Drilled the HS-610/HS-614 |
October 7, 2001 |
If you look on page 3PP of the plans for the empennage you'll see
the detail for the forward spar showing where the HS-610/HS-614
attaches to the HS-602s. The drilling pattern is shown on the
drawing, and at four stations there is a big oval which says
"Drill in Assembly with Fuselage".
What that means is "DON'T DRILL IT NOW, DUMMY". I, of course,
did drill it early. Fortunately I drilled it only with a #30 drill
and these holes are NOT for rivets, but will later be assembled
with bolts. Therefore, I can clamp and align with the fuselage
and THEN drill them out to the actual size when the time comes.
Whew! I'm not totally screwed on this one! :)
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Drilled Ribs to Forward HS Spar |
October 28, 2001 |
I am still working on getting the hang of aligning the ribs when
I drill. I was drilling through one of the
HS-608 ribs and I got the holes WAY too close to the web. This
resulted in me having
to order a replacement. My first replacement part! (I knew it had
to happen eventually!)
Update ... it wasn't my last. I continued to have problems with
alignment on the HS, and kept not being happy with it, and finally
ended up replacing more parts until I was happy. I chalk
this up to the HS being my "construction classroom" and,
in that light, it was cheap training. Ribs for the HS really are
quite inexpensive. :)
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Cut Stiffeners Wrong |
May 18, 2002 |
Ok, this was just plain stupid. The rudder stiffeners need to be
tapered, and they are pre-marked to show just how the tapers should
be cut. This should be a no-brainer, but the first pair I did were
arranged such that the mark in the middle of the stiffener which
indicates the ending point of the taper really was about right in
the middle.
I didn't cross-check with other stiffeners before I marked, and cut,
these two. When I went to do the next two (Marilyn was doing the
marking of these next ones .... while I trimmed on the bandsaw) I
saw that they were marked in the opposite direction! I wasn't SURE
this was wrong, but it certainly seemed wrong, and the only smart
thing I did during this whole affair was to stop immediately
and make sure we were doing the right thing.
We weren't. :) Just remember ... "If it looks wrong, it probably
is wrong." That kind of thinking saved me in this case.
I "stole" some stiffener material (not pre-cut, but just
simple aluminum angle) from the elevator stiffener stock and fabricated
replacements. It was very easy to do, and I used the messed-up stiffeners
as a drill guide. Piece of cake. All I need to do now is make sure I
still have enough stiffener stock for the elevators, and order another
length if I don't.
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Mis-Drilled Skin! |
August 16, 2002 |
I started on finishing the drilling of the stiffeners to the skin, and
made a tragic mistake. I grabbed the wrong stiffener, not realizing, and
drilled it to the wrong position. The mistake was severe enough (and when
combined with the other mis-drilling above) I decided to replace the
skin. Damn.
Aside from the obvious not-paying-close-enough-attention stupidity in
evidence here, I think there is a critical issue at play which caused
these mistakes. Complacency. I built the right elevator with NO problems
at all ... and in doing so became complacent in building the left. A
(somewhat expensive) lesson learned. On the up-side, I'll get to start
fresh on the left elevator and do it right, and will at the same
time re-work the stiffeners to correct a rivet hole spacing issue that
I was unhappy with.
Still, it sucks to make a mistake and screw up parts. Truly sucks.
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Mis-Drilled Tiedown Bar |
March 2, 2003 |
We got moving too quickly and mis-drilled the tiedown bar. We drilled before
we measured to the outboard edge of the spar to insure that the edge of the
tiedown bar was parallel with the spar end. This caused us to mis-drill the
lower holes by about 1/8 of an inch! Stupid, but there you have it. Measure
twice, drill once ... should be the motto. The trick is sticking to it and
never cutting and/or drilling too soon!
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