Hate to tell you this, but the FUS-30 doubler is a second .032. Is the
tailcone done already? Sounds like it. If so, like me, you're in for a lot
of work.
Is it necessary? As you know, the consensus certainly is "yes" to avoid
tailcone cracking, although there are people who have managed without -- but
I'm not sure where they land. I decided I had to do it, and better do it
before I cut the elevator tube holes.
I used FUS-30 parts from MAM, that came with the bottom bends partially
started. It still wasn't easy to control. If you're making your own doubler
from stock, check with Ben Ransom, who made a nice wood form around which he
made the bottom center tail bends. At one point Ben had several pics of that
-- perhaps they're on the builders web site, or his own site. No doubt, he
will pop up here.
It took me two tries (different pieces), and two months of on and off work
-- the way I did it. I started by locating & drilling the tailspring bolt
hole, to set the center point. I'd recommend adding some rivets on the
bottom in line at that point too, for extra securing with clecos -- you'll
want some extra before you're done anyway -- and they'll help you hug the
bottom of the existing skin as you work your way up. Then I rolled up to the
first rivets on one side, used lots of clamps to hold it, and hole locator
pins to mark the first holes ("gently" hammered with a soft hammer from
outside the new piece to mark inside of second skin) then disassembled,
drilled those, reassembled to use pins to locate another couple of rivets,
and so on. At some point, with long bits and/or a right angle drill, which I
didn't have then, you can back drill some, but not all of the holes from the
inside. I would hate to count the number of times the new doubler(s) went on
and off and on again as I worked my way up, first one side, then the other.
A couple of those rivets decided they wanted to grow up to be 5/32. <g> But
those are symmetrically positioned -- quite artistic. <g> After matching the
existing rivets you add additional additional "X" rivet lines, etc. Though I
did that last, before final assembly, you might find it easier to control if
you do that along the way. It's nice to have help for the final
epoxy-slathered assembly.
After my ordeal had passed, someone suggested using a piece of light plastic
of some wort wrapped around the outside to mark rivet locations onto as one
complete template for the holes in the doubler. I'm not exactly sure how
that might work, but it would have to be better than the way I did it if you
can figure it out. If somebody has that procedure nailed, hopefully they'll
sound off here too.
You may have to widen your tailspring clamp, though I was able to use a
little C-clamp persuasion (per Wayne's suggestion, as I recall) to use the
existing tailspring clamp structure. If I had to do it a third time, I'd
build a new, slightly wider clamp structure. (Well, actually, I'd commit
hari kari before doing it a third time!) Hopefully you haven't mounted the
stabs yet. Your stab struts may need to be redone to a longer length. Been
there too.
The way I did it was a grueling job... no two ways about it. Wait, that's
not right, I did it two ways, actually. <g> I'm glad I have it now, but if
I'd known what it was going to take... I might not have done it. Of course,
that applies to the whole project rather often, too. <g> There are several
annotated pics on my site in the "old" gallery, in the fuselage sub-gallery,
I think.
Ron
http://n254mr.com
On Tue, Apr 21, 2009 at 1:57 PM, <schaumr@dcsol.com> wrote:
Hi All,
Just getting ready to close up the tail cone/ fin area and wanted to clear
up
one last thing before doing so. Since my kit #786 came with a 0.032"
FUS-30
wrap (I believe the old ones were 0.020"), I assumed an additional FUS-30
reinforcement was superfluous. Is this a correct assumption, or is the
group
advocating bringing this area to a bullet-stopping 0.064"? The current
FUS-
30 was a nightmare to wrangle to the right shape...I can't imagine two of
these on top of each other.
Rob
Rebel 786
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