The Murphy Builders Site

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Mike and othe SR builders,

My SR is about at the same stage. Corner wraps have all be installed and
drilled to #40. Nice to be working on the fuselage - it's starting to look
like an airplane.

I did rivet the tailcone to the cabin botton as per instructions. Did not
have a problem. There were a few things that I did that made installing the
1/8" angles to the cargo area shear webs easier (using some hints from
previous posts):

* when building the cabin don't rivet the angles for the middle shear webs
to the cabin, just cleco
* for the angles that can be removed, I positioned the angles then
backdrilled a #40 hole at the front and back, then removed and used an extra
shear web as template to drill all holes to #40. This was easier than
drilling all holes in place
* I purchased a right angle attachment for my Dremel tool, worked well in
tight spaces, just make sure you use sharp drill bits.
* for bottom middle two shear webs (which are riveted to cabin) you can
pivot one of the angle pairs up which will give you access to the other,
backdrill to #40. Restore pivoted angle into place, then backdrill it to
#40. Easy now to drill to #30 using the original pilot holes in shear web.
Last few holes nearest cabin can't be accessed angle is pivoted, so I had to
drilled between the shear web pilot holes.

One problem I'm having is the sill to bottom corner wrap transition. I have
a gap. I used a metal shrinker on the corner wrap but this still leaves a
gap. Can't see how to shrink or bend the sill unless this is done before the
cabin is built, too late for me now. MAM suggests trimming the sill
extremely short and filling with Proseal fillet. That's probably what I'll
do.

As I see the fuselage taking shape I'm thinking more about engine choices. I
would like to use a "modern" engine but there don't seem to be a lot of good
choices, and I'm not enough of an experimenter to entertain doing my own
auto conversion. Are there any SR builders planning on using the Crossflow
engines? As far as I know there are none flying in SRs. I wished some of the
planned 2 stroke diesels were available, but this appears to be only a dream
as who knows if/when these engine choices will arrive.

Tim Saxton
SR 060

-----Original Message-----
From: Mike Kimball [mailto:agt@mosquitonet.com]
Sent: Monday, October 08, 2001 11:03 AM
To: murphy-rebel@dcsol.com
Subject: Building my SR


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Someone on the list is interested in hearing how slowly I am progressing on
the fuselage for my Super Rebel. So here goes...The basic tailcone went
together very easily and quickly. Then the hard part. The cabin. The
"torsion box" where the main gear attaches is one of the first things that
gets built. That part was pretty fun. Sure seems stout. Then I got to the
sills. You have to do lots of fitting, cutting, refitting, etc. The only
tool I had that could cut the thick aluminum was a jigsaw. It worked, but
it was difficult. Incidentally, after I had finished riveting the sills on
with 3/16 rivets I had an opportunity to see the demonstrator and noted that
it was riveted on with 1/8 rivets. I couldn't wait to get back and check
the instructions. Sure enough, it says to use 3/16 rivets. The two topmost
rivets are so close together, the heads actually touch each other. Clearly
designed at one time to use 1/8 rivets. They must have changed their minds
later. If you want two rivets in each flange tab the sills attach to, there
is no choice for the topmost flange tab: When using 3/16 rivets they will
be very close. The other part I don't enjoy too much on the fuselage is
that you have to fabricate a lot of little tabs to connect various bulkheads
and channels together. When fitting the cabin roof I was dismayed to see
that when aligning the front of the sheet with the wing carrythrough the
cabin hung over the edge of the fuselage ribs way more on one side than the
other. You can intentionally tweak the entire cabin structure to get the
skin to align, but then it doesn't lay flat on the upper bulkheads and the
cabin would be out of true. I opted to true up the cabin structure,
measuring up, down, left, right, comparing one side to the other, etc., then
I trimmed the cabin top, taking much more material off one side than the
other. It should also be noted that the cabin had to be clamped in place
when true, then parts were drilled and clecoed. It definitely wasn't very
close to true when allowed to take it's own shape.

I just discovered the other day that the plans set you up for a big problem
later on by having you rivet the sills on without installing the bolts that
hold the lower gear attach brackets in place first. Now there is no way to
install the bolts without drilling a hole in the sill. Oh well. Four water
drain holes for the fuselage.

The plans also have you attaching the tailcone to the cabin at the bottom
only, pretty early on. Don't do that. Leave the tailcone unriveted until
everything on the tailcone and cargo area shear webs are final drilled.
There were lots of occasions where it was convenient to be able to separate
the cabin and tailcone.

I have finished about 14 hours of deburring and am now ready to rivet the
corner wraps in place and the tailcone to the fuselage. I was planning on
riveting the corner wraps from the back to the front, then I would rivet the
last four corner wraps at the same time I rivet the tailcone to the cabin.
Sound OK to you folks?

Sure seems funny that the tailcone is attached so well to the cabin at the
bottom, and so minimally at the top and sides. Apparently the greatest
force trying to separate the tailcone from the cabin is the force the
tailwheel exerts on the structure. The downward force of the horizontal
stabilizer and sidewards force from the rudder when deflected in flight must
be much less or there would be a stronger connection between the cabin and
tailcone at the top and sides. I was actually toying with running some
stringers at the top and sides. Anyone else do anything like that?

Mike Kimball
SR #044

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The list archives are located at:
http://www.dcsol.com:81/public/default.htm
username: rebel password: builder

Someone on the list is interested in hearing how
slowly I am progressing on
the fuselage for my Super Rebel. So here goes...The
basic tailcone went
together very easily and quickly. Then the hard
part. The cabin. The
"torsion box" where the main gear attaches is one of
the first things that
gets built. That part was pretty fun. Sure seems
stout. Then I got to the
sills. You have to do lots of fitting, cutting,
refitting, etc. The only
tool I had that could cut the thick aluminum was a
jigsaw. It worked, but
it was difficult. Incidentally, after I had
finished riveting the sills on
with 3/16 rivets I had an opportunity to see the
demonstrator and noted that
it was riveted on with 1/8 rivets. I couldn't wait
to get back and check
the instructions. Sure enough, it says to use 3/16
rivets. The two topmost
rivets are so close together, the heads actually
touch each other. Clearly
designed at one time to use 1/8 rivets. They must
have changed their minds
later. If you want two rivets in each flange tab
the sills attach to, there
is no choice for the topmost flange tab: When using
3/16 rivets they will
be very close. The other part I don't enjoy too
much on the fuselage is
that you have to fabricate a lot of little tabs to
connect various bulkheads
and channels together. When fitting the cabin roof
I was dismayed to see
that when aligning the front of the sheet with the
wing carrythrough the
cabin hung over the edge of the fuselage ribs way
more on one side than the
other. You can intentionally tweak the entire cabin
structure to get the
skin to align, but then it doesn't lay flat on the
upper bulkheads and the
cabin would be out of true. I opted to true up the
cabin structure,
measuring up, down, left, right, comparing one side
to the other, etc., then
I trimmed the cabin top, taking much more material
off one side than the
other. It should also be noted that the cabin had
to be clamped in place
when true, then parts were drilled and clecoed. It
definitely wasn't very
close to true when allowed to take it's own shape.

I just discovered the other day that the plans set
you up for a big problem
later on by having you rivet the sills on without
installing the bolts that
hold the lower gear attach brackets in place first.
Now there is no way to
install the bolts without drilling a hole in the
sill. Oh well. Four water
drain holes for the fuselage.

The plans also have you attaching the tailcone to
the cabin at the bottom
only, pretty early on. Don't do that. Leave the
tailcone unriveted until
everything on the tailcone and cargo area shear webs
are final drilled.
There were lots of occasions where it was convenient
to be able to separate
the cabin and tailcone.

I have finished about 14 hours of deburring and am
now ready to rivet the
corner wraps in place and the tailcone to the
fuselage. I was planning on
riveting the corner wraps from the back to the
front, then I would rivet the
last four corner wraps at the same time I rivet the
tailcone to the cabin.
Sound OK to you folks?

Sure seems funny that the tailcone is attached so
well to the cabin at the
bottom, and so minimally at the top and sides.
Apparently the greatest
force trying to separate the tailcone from the cabin
is the force the
tailwheel exerts on the structure. The downward
force of the horizontal
stabilizer and sidewards force from the rudder when
deflected in flight must
be much less or there would be a stronger connection
between the cabin and
tailcone at the top and sides. I was actually
toying with running some
stringers at the top and sides. Anyone else do
anything like that?

Mike Kimball
SR #044

You have received this message because you have
subscribed to the
murphy-rebel mailing list.
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with "unsubscribe murphy-rebel" in the body of the
message.
For assistance contact mike.davis@dcsol.com

Mike and othe SR builders,

As I see the fuselage taking shape I'm thinking more about engine choices.

would like to use a "modern" engine but there don't seem to be a lot of

choices, and I'm not enough of an experimenter to entertain doing my own
auto conversion. Are there any SR builders planning on using the Crossflow
engines? As far as I know there are none flying in SRs. I wished some of

planned 2 stroke diesels were available, but this appears to be only a

as who knows if/when these engine choices will arrive.

Tim Saxton
SR 060