[rebel-builders] Tail fairings 818R
Posted: Sun Feb 19, 2012 8:06 pm
In metal, IMHO the tail fairings can be some of the most complex
pieces to form on the whole plane. Of course, if the front of the fin
is offset to the left per the manual, the top fairings are different
on each side. I think I made 7 before getting them right -- days worth
of work. :-( If I were doing it again, I'd probably build them in
fiberglass, which would be a lot easier, though heavier.
If you haven't already, first make a template with poster board to get
the right size of the pieces and the position of the angles and
curves. To form the metal, I then tried to copy the technique Si Smith
showed me at OSH a few years ago -- using a brake to make a bunch of
finely spaced mini-bends, where the rear end point of all the bend
lines is essentially constant, and the bend lines fan out, perhaps
1/8" apart at the front edge to create the curved radius around the
fuse on the front edge. (Because of the way the two attachment angles
sort of fade out to a single 90 deg. bend at the rear, I couldn't
figure any way to do this with a roller.) The template tells you where
to start and stop making these "rounding" bends, of course. You end up
with a very flat section at the rear with the right angle bend, and
the forward rounded edge with the upper and horizontal flanges, which
were bent last. Most of the screws did not end up going into stab or
fin rib or other flanges -- just into one layer of metal skin -- but
some do grab onto double thickness of metal underneath. I used a few
Click Bond #6 mini-nutplates under the top fairings to hold the small
forward wrap around pieces. Be careful where you put the holes for
screws. One of mine ended up precisely on top of the left stab forward
attach bracket, and even a skimpy 3/8" sheet metal screw is a little
too long in that one hole. I used #6 sheet metal screws -- mostly
because I suspect they'll eventually wear and I may have to upsize to
#8 down the road.
It's easier to show and tell than to write, but you can see pictures
of mine by searching for "tail fairings" (no quotes) on
http://n254mr.com Looks like I never got a picture of the completed
job with the small rubber channel on a couple of leading edges, but
I'll take one and post it later today. If you'd like another photo
from a different angle than what you find, let me know and I'll try to
snap it for you.
Ron
N254MR
On Sat, Oct 9, 2010 at 2:33 AM, <mikeh@dcsol.com> wrote:
[quote]Hi all,
pieces to form on the whole plane. Of course, if the front of the fin
is offset to the left per the manual, the top fairings are different
on each side. I think I made 7 before getting them right -- days worth
of work. :-( If I were doing it again, I'd probably build them in
fiberglass, which would be a lot easier, though heavier.
If you haven't already, first make a template with poster board to get
the right size of the pieces and the position of the angles and
curves. To form the metal, I then tried to copy the technique Si Smith
showed me at OSH a few years ago -- using a brake to make a bunch of
finely spaced mini-bends, where the rear end point of all the bend
lines is essentially constant, and the bend lines fan out, perhaps
1/8" apart at the front edge to create the curved radius around the
fuse on the front edge. (Because of the way the two attachment angles
sort of fade out to a single 90 deg. bend at the rear, I couldn't
figure any way to do this with a roller.) The template tells you where
to start and stop making these "rounding" bends, of course. You end up
with a very flat section at the rear with the right angle bend, and
the forward rounded edge with the upper and horizontal flanges, which
were bent last. Most of the screws did not end up going into stab or
fin rib or other flanges -- just into one layer of metal skin -- but
some do grab onto double thickness of metal underneath. I used a few
Click Bond #6 mini-nutplates under the top fairings to hold the small
forward wrap around pieces. Be careful where you put the holes for
screws. One of mine ended up precisely on top of the left stab forward
attach bracket, and even a skimpy 3/8" sheet metal screw is a little
too long in that one hole. I used #6 sheet metal screws -- mostly
because I suspect they'll eventually wear and I may have to upsize to
#8 down the road.
It's easier to show and tell than to write, but you can see pictures
of mine by searching for "tail fairings" (no quotes) on
http://n254mr.com Looks like I never got a picture of the completed
job with the small rubber channel on a couple of leading edges, but
I'll take one and post it later today. If you'd like another photo
from a different angle than what you find, let me know and I'll try to
snap it for you.
Ron
N254MR
On Sat, Oct 9, 2010 at 2:33 AM, <mikeh@dcsol.com> wrote:
[quote]Hi all,