Bill Bowne
Apr 01, 1997, 01:00 AM
<table border="0" cellpadding="5" width="100%" bgcolor="#C0C0C0">
<tr>
<td width="50%"><img src="http://static.rcgroups.com/articles/ezonemag/plans/corvus/corv_frt.jpg" align="left" hspace="5" vspace="5" width="357" height="247"></td>
<td width="50%"><h2><font color="#000080">Stats:</font></h2>
<ul>
<li><font color="#000080"><strong>Wing Span:</strong> 74 inches</font></li>
<li><font color="#000080"><strong>Wing Area: </strong>616 sq. in.</font></li>
<li><font color="#000080"><strong>Weight:</strong> 80 oz.</font></li>
<li><font color="#000080"><strong>Wing loading:</strong> 18.8 oz/ sq. ft.</font></li>
<li><font color="#000080"><strong>Airfoil: </strong>Eppler 221</font></li>
<li><font color="#000080"><strong>Controls:</strong> throttle, flaps, elevator, aileron,
rudder. Computer radio recommended</font></li>
<li><font color="#000080"><strong>Recommended power system:</strong> Astro 25 Direct Drive
motor with a 16 cell pack</font></li>
</ul>
</td>
</tr>
</table>
<h2 align="left">Introduction</h2>
<p>The Corvus (Latin for "crow") started as a response to the German glass kits
my wife and I saw when we were assigned there. They really flew well, but they were
expensive and used materials I don’t enjoy working with: Fiberglass and Plastic. But,
since she wanted a higher performance glider than her Sensoar and her Eclipse, I decided
to pursue domestic tranquillity by designing a higher performance wooden glider.</p>
<p>No, the Corvus isn’t as hot as a Calibra, but it’s still efficient enough
that Mickey came in third in the limited motor run All-Up/Last-Down run at the 1996 LeHigh
Valley Electric Fly. She only lost second place by a few seconds, and I think her not
having a folding prop was the deciding factor. Yes, the Corvus now has a folding prop!</p>
<p>Corvus is built strong. Each top and bottom spar consists of two pieces of 1/8 by 1/4
spruce, tapering one of the 1/8 X 1/4 pieces in each spar to allow a gradual decrease in
spar thickness towards the tip. This reduces the number of stress points in the design.
Likewise, the light ply in the forward fuse helps protect against some off-runway
landings. The Eppler 221 airfoil I used is still a valid airfoil for gliders and fast
aerobatic models.</p>
<p>Corvus was designed around the Astro 25 direct drive sport motor, but an Astro 40 will
fit. I know geared drive motors could fit in the nose and fly the model, but the 25 is
what we had on hand! Besides, it works well, especially in the fast zoom climbs. </p>
<p>Corvus has flaps and ailerons, although our radio won’t let us use crow. So, we (I
get to fly the Corvus, <i>occasionally</i>) use the flaps to shorten approaches and, when
the lift is really strong, to tighten Corvus’ turning circle. The wing tips
aren’t the most efficient, but they help keep the model from ground looping on
landing.</p>
<p>The fuselage is roomy enough for two standard servos, 14 *1000 SCR cells, an Astro 205
controller, and a safety switch. We have, on occasion, put 14 * 1400 SCR cells in the
Corvus, but the glide definitely suffers. Besides, the 1400s are now in Mickey’s FAI
25-powered Arcus (she finally got her German glider!). She loves those nearly vertical
climb outs!</p>
<p> </p>
<p align="center"><img src="http://static.rcgroups.com/articles/ezonemag/plans/corvus/corvplan.gif" width="607" height="364"></p>
<p align="center"><font size="2"><strong>This and other high-quality plans are available
through the <a href="http://www.rcgroups.com/store/catalog">E Zone's online store</a>.</strong></font></p>
<p> </p>
<h2>Construction</h2>
<p>I like to completely kit a model before I start building. We have limited construction
space, and I am a neatnik about my work area. I hate having to keep putting away and
taking out my jig saw and sander whilst I’m working. I used a mixture of
woodworker’s glue (Elmer’s), epoxy, and cyanoacrylates.</p>
<p> </p>
<blockquote>
<h3>Wings</h3>
</blockquote>
<blockquote>
<p>The original Corvus wing was built on an Adjusto-Jig, but it can be built on a flat
surface. <ol>
<li>Laminate two sets of spars per the plans. Note that they taper in different areas!</li>
<li>Pin down the bottom leading edge, trailing edge, and center section sheeting.</li>
<li>Glue the bottom spars to the sheeting</li>
<li>Glue the trailing edge to the rear of the trailing edge sheeting</li>
<li>Cut servo lead holes in the inner ribs.</li>
<li>Glue all ribs to the spars, trailing edge, trailing edge sheeting, and the rear part of
the leading edge sheeting.</li>
<li>Add the top spar set.</li>
<li>Glue on the top trailing edge sheeting.</li>
<li>Glue on the leading edge</li>
<li>Add the top leading edge sheeting. Wet the top (outside) of the leading edge sheeting to
make it flexible.</li>
<li>Glue in all shear webs from root to tip.</li>
<li>Add the top center section sheeting</li>
<li>Remove the wing panel from the board</li>
<li>Glue the bottom leading edge sheeting to the front of the ribs and to the leading edge.</li>
<li>Build the aileron servo mounts and sheet the between ribs R8 and R9, BOTTOM OF WING
ONLY!</li>
<li>Sand the spar ends at the wing tip rib (R14) flush with R14. DO NOT PUT ON THE WING TIPS
UNTIL AFTER THE WING PANELS ARE JOINED!</li>
<li>Glue the wing center trailing edge in place (if you aren’t using flaps, glue them
in place now, too).</li>
<li>Round the leading edge, shape the tips, and sand the rest of the wing to shape.</li>
<li>Taper the leading edges of the ailerons to shape. They will be hinged at the top of the
aileron, so don’t taper them to a V!</li>
<li>Repeat for the second wing panel.</li>
<li>Block one wing panel on a flat surface and use a long sander to square up the root rib.
Sand the other root rib to the desired dihedral angle.</li>
<li>Join both panels. The desired dihedral is 1/2" PER PANEL, or 1" under the
elevated tip with the first panel flat on the building surface.</li>
<li>Wrap the center section with fiberglass tape and epoxy, then let it cure.</li>
<li>Trial fit a block of soft 3/4" triangular balsa to each wing tip.</li>
<li>Notch the wing tip block for the 1/32" ply tip skids, then glue the skids to the
blocks</li>
<li>Glue the blocks to the wing tips. </li>
<li>Sand the blocks to the airfoil shape.</li>
<li>Place the wing aside until final assembly.</li>
</ol>
</blockquote>
<blockquote>
<blockquote>
<p> </p>
</blockquote>
</blockquote>
<blockquote>
<h3>Tail Surfaces</h3>
</blockquote>
<blockquote>
<p>All tail surfaces are built on a flat building surface.</p>
<blockquote>
<h4>A. Horizontal surfaces:</h4>
<blockquote>
<ol>
<li>Pin the horizontal stab trailing edge in place</li>
<li>Glue S4 and S5 to the trailing edge</li>
<li>Trim the leading edges to fit and glue them to S4 and S5</li>
<li>Glue the corner braces and 3/16" square "ribs" in place</li>
<li>Fit the elevators in place, then epoxy the music wire joiner into each one</li>
<li>Remove the assembly from the board.</li>
<li>Sand the leading edge of the elevators to a "V" shape.</li>
<li>Round the edges of the horizontal stab and blend it into the elevators at the tips.</li>
</ol>
<blockquote>
<p> </p>
</blockquote>
</blockquote>
<h4>B. Vertical Surfaces:</h4>
<blockquote>
<ol>
<li>Pin the vertical stab leading edge, trailing edge, rudder leading edge, and rudder
trailing edges in place</li>
<li>Glue S1 and S2 in place. Be sure not to glue the rudder and vertical stab together!</li>
<li>Trim the vertical stab/rudder top (it is one piece and will be separated later) and glue
it in place.</li>
<li>Fit the corner braces and 3/16" square "ribs" in place, then glue them
down.</li>
<li>Glue S3 to the front of the vertical stab.</li>
<li>Remove the assembly from the board and round the edges.</li>
<li>Separate the vertical stab from the rudder.</li>
<li>Sand the leading edge of the rudder to a "V" shape.</li>
</ol>
<blockquote>
<p> </p>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<blockquote>
<h3>Fuselage </h3>
</blockquote>
<blockquote>
<ol>
<li>Build bulkhead F2 from its component parts, then set it aside to dry.</li>
<li>Pin the fuselage sides onto a flat building board. I like to set the two sides together,
one above the other, top to top. This helps prevent me from inadvertently making two right
or two left sides.</li>
<li>Glue on the 1/8" wing and horizontal stab doublers.</li>
<li>Add the aft 3/8" tri-stock, both top and bottom.</li>
<li>Add the 1/8" square aft fuselage verticals.</li>
<li>Glue on the 3/16" square front top strips</li>
<li>With a razor saw, notch the bottoms of the forward bottom 3/4" tri-stock so that it
will bend around the nose curve and glue it in place. </li>
<li>With a square, glue F1 and F2 to one side of the fuselage and let dry</li>
<li>Remove the other fuselage side from the board and glue it to F1 and F2.</li>
<li>Sheet the bottom between F1 and F2</li>
<li>Add the plywood wing hold down plate</li>
<li>Taper the inside of the aft fuselage sides.</li>
<li>Notch the stab doubler and the bottom 3/8" tri-stock to fit the rudder post</li>
<li>Clamp the aft sides together around the rudder post.</li>
<li>Sheet the top of the aft fuselage and join the bottom sides with several 1/8"
square cross-braces.</li>
<li>When the fuselage has dried, remove the vertical stab.</li>
<li>Not shown on the plans are some motor cooling holes I later added to the firewall. Drill
a few around the edges of where the motor mount will cover BEFORE installing the firewall
into the model.</li>
<li>Bolt the motor mount to the firewall, then slide the motor into the motor mount. MAKE
SURE THE BRUSHES POINT UP AND DOWN!</li>
<li>Cover all motor openings with masking tape.</li>
<li>Over the top fuselage drawing, align the fuselage with the centerline.</li>
<li>Align the motor mount and motor with the desired right and down thrust, then glue the
firewall in place.</li>
<li>Glue the nose hatch block into place.</li>
<li>Tack glue the hatch into place. You’ll probably have to hollow out the block to fit
the motor brushes. </li>
<li>Fill the edges of the nose opening with scrap wood (enough to fill in behind the 2"
spinner).</li>
<li>Bolt on an old spinner. I save old spinners and use old prop hubs to properly fit them
onto motor shafts.</li>
<li>Sand, Sand, Sand! This is like making one of those old balsa pattern planes (like the
Mach One).</li>
<li>Pop off the hatch, cut out the air intake, and set up the hatch latch mechanism.</li>
<li>Remove the spinner and remove excess balsa from around the shaft. For better motor
cooling, leave a gap on the bottom edge of the spinner ring to admit air.</li>
<li>Brace the fuselage, then align and glue on the horizontal and vertical stabilizers. Note
that the vertical stab has a tab to fit into the horizontal stab. For easier installation,
I recommend using a slower glue, such as an aliphatic (polyvinyl) woodworkers glue. Let
dry</li>
<li>Align the wing in place, then drill for the wing dowel.</li>
<li>Remove the wing and glue the dowel in place.</li>
<li>Return the wing to the fuselage, and realign it.</li>
<li>Drill and tap the two wing bolt block holes.</li>
<li>Fit the front wing block onto the wing, then sand it to shape.</li>
</ol>
<blockquote>
<p> </p>
</blockquote>
</blockquote>
<blockquote>
<h3>Final Assembly</h3>
</blockquote>
<blockquote>
<ol>
<li>Set up wing servos and install fuselage pushrod tubes.</li>
<li>Cover. Be sure to leave a small opening in the rear belly for cooling air exhaust. </li>
<li>Hinge control surfaces and the nose hatch</li>
</ol>
<p>Trial balance with all components placed in position before finalizing installations. I
used three Futaba S-133s in the wings (two for ailerons and one for flaps) and two
S-148’s in the fuselage (rudder and elevator). Thanks to using the S-148s in the
fuselage, plus a 500 mah receiver pack, I had to put the receiver behind the rudder and
elevator servos. I added a balsa floor to the fuselage for this, and I cable tied the
receiver to the elevator and rudder cablerod outers.</p>
<p>Add safety switch on a plywood deck behind the motor, leaving enough room to clear the
hatch.</p>
<p>Install a hatch hold down mechanism (I use a Goldberg hold down PLUS a rubber band to
hold the hatch down. You may want to do likewise, use Velcro, or do something totally
different!</p>
<p>I use a belly skid made from coffee can (or other similar consumable) lid plastic and
double-sided foam tape. There are enough colors available to match whatever color scheme
you use on your Corvus. I cut the lid material into 1" strips and adhere it with long
strips of tape. For really long skids, I use multiple strips of lid material, and let the
forward strips overlap the rearward ones. These are really rugged and survive well, even
on pavement.</p>
</blockquote>
<p> </p>
<h2>Flying</h2>
<p>I have mixed feelings about evaluations of flyability. Each model is built by a
different person, with different building and flying skills. I’ve seen Sig Kadets
that were touchy, hard-to fly models due to poor building techniques, for example.
Likewise, the descriptions of qualities like "mildly aerobatic" are greatly
different to different people. Some people consider a model that’ll do a loop from
level flight as being very aerobatic, whilst others consider a model to be a pig unless
it’ll do the entire Master’s pattern at half-throttle (or less). </p>
<p>Corvus is not a gasbag floater. If you want one of those, put a geared 15 in an
Airtronics Oly II (I swear those things’ll thermal at midnight, on firefly light!).
Corvus is a clean, efficient airframe that will rapidly climb to thermal altitude and can
work wider lift. I believe that if you use limited flaps and/or flaperons, you can stay in
fairly narrow lift (Our older Futaba radios won’t support either flaperons or crow,
so we mainly use flaps for landing.). Corvus’s flaps will definitely cut your landing
distance significantly, but you must maintain forward stick to keep the nose down (or, if
you have a better radio than we do, use mixing).</p>
<p>Stalls are quite gentle. Excessive back pressure results in a straight-ahead nose drop
and quick recovery. The hardest part about flying it is keeping from overshooting the
runway!</p>
<p>I believe Corvus is fairly maneuverable. The rolls are slow, even at maximum throw, but
it will roll, loop, stall turn, and (barely) spin. Snaps are slow, and it is hard to do a
decent Avalanche with it. It is quite fast, strong, and much easier to fix than fiberglass
and plastic! </p>
<table border="0" cellpadding="5" width="100%">
<tr>
<td width="50%">Full size plans are available through the <a href="http://www.rcgroups.com/store/catalog">E Zone's online store.</a>
</td>
<td width="50%"><img src="http://static.rcgroups.com/articles/ezonemag/plans/corvus/corvback.jpg" width="363" height="221"><p> </td>
</tr>
</table>
<tr>
<td width="50%"><img src="http://static.rcgroups.com/articles/ezonemag/plans/corvus/corv_frt.jpg" align="left" hspace="5" vspace="5" width="357" height="247"></td>
<td width="50%"><h2><font color="#000080">Stats:</font></h2>
<ul>
<li><font color="#000080"><strong>Wing Span:</strong> 74 inches</font></li>
<li><font color="#000080"><strong>Wing Area: </strong>616 sq. in.</font></li>
<li><font color="#000080"><strong>Weight:</strong> 80 oz.</font></li>
<li><font color="#000080"><strong>Wing loading:</strong> 18.8 oz/ sq. ft.</font></li>
<li><font color="#000080"><strong>Airfoil: </strong>Eppler 221</font></li>
<li><font color="#000080"><strong>Controls:</strong> throttle, flaps, elevator, aileron,
rudder. Computer radio recommended</font></li>
<li><font color="#000080"><strong>Recommended power system:</strong> Astro 25 Direct Drive
motor with a 16 cell pack</font></li>
</ul>
</td>
</tr>
</table>
<h2 align="left">Introduction</h2>
<p>The Corvus (Latin for "crow") started as a response to the German glass kits
my wife and I saw when we were assigned there. They really flew well, but they were
expensive and used materials I don’t enjoy working with: Fiberglass and Plastic. But,
since she wanted a higher performance glider than her Sensoar and her Eclipse, I decided
to pursue domestic tranquillity by designing a higher performance wooden glider.</p>
<p>No, the Corvus isn’t as hot as a Calibra, but it’s still efficient enough
that Mickey came in third in the limited motor run All-Up/Last-Down run at the 1996 LeHigh
Valley Electric Fly. She only lost second place by a few seconds, and I think her not
having a folding prop was the deciding factor. Yes, the Corvus now has a folding prop!</p>
<p>Corvus is built strong. Each top and bottom spar consists of two pieces of 1/8 by 1/4
spruce, tapering one of the 1/8 X 1/4 pieces in each spar to allow a gradual decrease in
spar thickness towards the tip. This reduces the number of stress points in the design.
Likewise, the light ply in the forward fuse helps protect against some off-runway
landings. The Eppler 221 airfoil I used is still a valid airfoil for gliders and fast
aerobatic models.</p>
<p>Corvus was designed around the Astro 25 direct drive sport motor, but an Astro 40 will
fit. I know geared drive motors could fit in the nose and fly the model, but the 25 is
what we had on hand! Besides, it works well, especially in the fast zoom climbs. </p>
<p>Corvus has flaps and ailerons, although our radio won’t let us use crow. So, we (I
get to fly the Corvus, <i>occasionally</i>) use the flaps to shorten approaches and, when
the lift is really strong, to tighten Corvus’ turning circle. The wing tips
aren’t the most efficient, but they help keep the model from ground looping on
landing.</p>
<p>The fuselage is roomy enough for two standard servos, 14 *1000 SCR cells, an Astro 205
controller, and a safety switch. We have, on occasion, put 14 * 1400 SCR cells in the
Corvus, but the glide definitely suffers. Besides, the 1400s are now in Mickey’s FAI
25-powered Arcus (she finally got her German glider!). She loves those nearly vertical
climb outs!</p>
<p> </p>
<p align="center"><img src="http://static.rcgroups.com/articles/ezonemag/plans/corvus/corvplan.gif" width="607" height="364"></p>
<p align="center"><font size="2"><strong>This and other high-quality plans are available
through the <a href="http://www.rcgroups.com/store/catalog">E Zone's online store</a>.</strong></font></p>
<p> </p>
<h2>Construction</h2>
<p>I like to completely kit a model before I start building. We have limited construction
space, and I am a neatnik about my work area. I hate having to keep putting away and
taking out my jig saw and sander whilst I’m working. I used a mixture of
woodworker’s glue (Elmer’s), epoxy, and cyanoacrylates.</p>
<p> </p>
<blockquote>
<h3>Wings</h3>
</blockquote>
<blockquote>
<p>The original Corvus wing was built on an Adjusto-Jig, but it can be built on a flat
surface. <ol>
<li>Laminate two sets of spars per the plans. Note that they taper in different areas!</li>
<li>Pin down the bottom leading edge, trailing edge, and center section sheeting.</li>
<li>Glue the bottom spars to the sheeting</li>
<li>Glue the trailing edge to the rear of the trailing edge sheeting</li>
<li>Cut servo lead holes in the inner ribs.</li>
<li>Glue all ribs to the spars, trailing edge, trailing edge sheeting, and the rear part of
the leading edge sheeting.</li>
<li>Add the top spar set.</li>
<li>Glue on the top trailing edge sheeting.</li>
<li>Glue on the leading edge</li>
<li>Add the top leading edge sheeting. Wet the top (outside) of the leading edge sheeting to
make it flexible.</li>
<li>Glue in all shear webs from root to tip.</li>
<li>Add the top center section sheeting</li>
<li>Remove the wing panel from the board</li>
<li>Glue the bottom leading edge sheeting to the front of the ribs and to the leading edge.</li>
<li>Build the aileron servo mounts and sheet the between ribs R8 and R9, BOTTOM OF WING
ONLY!</li>
<li>Sand the spar ends at the wing tip rib (R14) flush with R14. DO NOT PUT ON THE WING TIPS
UNTIL AFTER THE WING PANELS ARE JOINED!</li>
<li>Glue the wing center trailing edge in place (if you aren’t using flaps, glue them
in place now, too).</li>
<li>Round the leading edge, shape the tips, and sand the rest of the wing to shape.</li>
<li>Taper the leading edges of the ailerons to shape. They will be hinged at the top of the
aileron, so don’t taper them to a V!</li>
<li>Repeat for the second wing panel.</li>
<li>Block one wing panel on a flat surface and use a long sander to square up the root rib.
Sand the other root rib to the desired dihedral angle.</li>
<li>Join both panels. The desired dihedral is 1/2" PER PANEL, or 1" under the
elevated tip with the first panel flat on the building surface.</li>
<li>Wrap the center section with fiberglass tape and epoxy, then let it cure.</li>
<li>Trial fit a block of soft 3/4" triangular balsa to each wing tip.</li>
<li>Notch the wing tip block for the 1/32" ply tip skids, then glue the skids to the
blocks</li>
<li>Glue the blocks to the wing tips. </li>
<li>Sand the blocks to the airfoil shape.</li>
<li>Place the wing aside until final assembly.</li>
</ol>
</blockquote>
<blockquote>
<blockquote>
<p> </p>
</blockquote>
</blockquote>
<blockquote>
<h3>Tail Surfaces</h3>
</blockquote>
<blockquote>
<p>All tail surfaces are built on a flat building surface.</p>
<blockquote>
<h4>A. Horizontal surfaces:</h4>
<blockquote>
<ol>
<li>Pin the horizontal stab trailing edge in place</li>
<li>Glue S4 and S5 to the trailing edge</li>
<li>Trim the leading edges to fit and glue them to S4 and S5</li>
<li>Glue the corner braces and 3/16" square "ribs" in place</li>
<li>Fit the elevators in place, then epoxy the music wire joiner into each one</li>
<li>Remove the assembly from the board.</li>
<li>Sand the leading edge of the elevators to a "V" shape.</li>
<li>Round the edges of the horizontal stab and blend it into the elevators at the tips.</li>
</ol>
<blockquote>
<p> </p>
</blockquote>
</blockquote>
<h4>B. Vertical Surfaces:</h4>
<blockquote>
<ol>
<li>Pin the vertical stab leading edge, trailing edge, rudder leading edge, and rudder
trailing edges in place</li>
<li>Glue S1 and S2 in place. Be sure not to glue the rudder and vertical stab together!</li>
<li>Trim the vertical stab/rudder top (it is one piece and will be separated later) and glue
it in place.</li>
<li>Fit the corner braces and 3/16" square "ribs" in place, then glue them
down.</li>
<li>Glue S3 to the front of the vertical stab.</li>
<li>Remove the assembly from the board and round the edges.</li>
<li>Separate the vertical stab from the rudder.</li>
<li>Sand the leading edge of the rudder to a "V" shape.</li>
</ol>
<blockquote>
<p> </p>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<blockquote>
<h3>Fuselage </h3>
</blockquote>
<blockquote>
<ol>
<li>Build bulkhead F2 from its component parts, then set it aside to dry.</li>
<li>Pin the fuselage sides onto a flat building board. I like to set the two sides together,
one above the other, top to top. This helps prevent me from inadvertently making two right
or two left sides.</li>
<li>Glue on the 1/8" wing and horizontal stab doublers.</li>
<li>Add the aft 3/8" tri-stock, both top and bottom.</li>
<li>Add the 1/8" square aft fuselage verticals.</li>
<li>Glue on the 3/16" square front top strips</li>
<li>With a razor saw, notch the bottoms of the forward bottom 3/4" tri-stock so that it
will bend around the nose curve and glue it in place. </li>
<li>With a square, glue F1 and F2 to one side of the fuselage and let dry</li>
<li>Remove the other fuselage side from the board and glue it to F1 and F2.</li>
<li>Sheet the bottom between F1 and F2</li>
<li>Add the plywood wing hold down plate</li>
<li>Taper the inside of the aft fuselage sides.</li>
<li>Notch the stab doubler and the bottom 3/8" tri-stock to fit the rudder post</li>
<li>Clamp the aft sides together around the rudder post.</li>
<li>Sheet the top of the aft fuselage and join the bottom sides with several 1/8"
square cross-braces.</li>
<li>When the fuselage has dried, remove the vertical stab.</li>
<li>Not shown on the plans are some motor cooling holes I later added to the firewall. Drill
a few around the edges of where the motor mount will cover BEFORE installing the firewall
into the model.</li>
<li>Bolt the motor mount to the firewall, then slide the motor into the motor mount. MAKE
SURE THE BRUSHES POINT UP AND DOWN!</li>
<li>Cover all motor openings with masking tape.</li>
<li>Over the top fuselage drawing, align the fuselage with the centerline.</li>
<li>Align the motor mount and motor with the desired right and down thrust, then glue the
firewall in place.</li>
<li>Glue the nose hatch block into place.</li>
<li>Tack glue the hatch into place. You’ll probably have to hollow out the block to fit
the motor brushes. </li>
<li>Fill the edges of the nose opening with scrap wood (enough to fill in behind the 2"
spinner).</li>
<li>Bolt on an old spinner. I save old spinners and use old prop hubs to properly fit them
onto motor shafts.</li>
<li>Sand, Sand, Sand! This is like making one of those old balsa pattern planes (like the
Mach One).</li>
<li>Pop off the hatch, cut out the air intake, and set up the hatch latch mechanism.</li>
<li>Remove the spinner and remove excess balsa from around the shaft. For better motor
cooling, leave a gap on the bottom edge of the spinner ring to admit air.</li>
<li>Brace the fuselage, then align and glue on the horizontal and vertical stabilizers. Note
that the vertical stab has a tab to fit into the horizontal stab. For easier installation,
I recommend using a slower glue, such as an aliphatic (polyvinyl) woodworkers glue. Let
dry</li>
<li>Align the wing in place, then drill for the wing dowel.</li>
<li>Remove the wing and glue the dowel in place.</li>
<li>Return the wing to the fuselage, and realign it.</li>
<li>Drill and tap the two wing bolt block holes.</li>
<li>Fit the front wing block onto the wing, then sand it to shape.</li>
</ol>
<blockquote>
<p> </p>
</blockquote>
</blockquote>
<blockquote>
<h3>Final Assembly</h3>
</blockquote>
<blockquote>
<ol>
<li>Set up wing servos and install fuselage pushrod tubes.</li>
<li>Cover. Be sure to leave a small opening in the rear belly for cooling air exhaust. </li>
<li>Hinge control surfaces and the nose hatch</li>
</ol>
<p>Trial balance with all components placed in position before finalizing installations. I
used three Futaba S-133s in the wings (two for ailerons and one for flaps) and two
S-148’s in the fuselage (rudder and elevator). Thanks to using the S-148s in the
fuselage, plus a 500 mah receiver pack, I had to put the receiver behind the rudder and
elevator servos. I added a balsa floor to the fuselage for this, and I cable tied the
receiver to the elevator and rudder cablerod outers.</p>
<p>Add safety switch on a plywood deck behind the motor, leaving enough room to clear the
hatch.</p>
<p>Install a hatch hold down mechanism (I use a Goldberg hold down PLUS a rubber band to
hold the hatch down. You may want to do likewise, use Velcro, or do something totally
different!</p>
<p>I use a belly skid made from coffee can (or other similar consumable) lid plastic and
double-sided foam tape. There are enough colors available to match whatever color scheme
you use on your Corvus. I cut the lid material into 1" strips and adhere it with long
strips of tape. For really long skids, I use multiple strips of lid material, and let the
forward strips overlap the rearward ones. These are really rugged and survive well, even
on pavement.</p>
</blockquote>
<p> </p>
<h2>Flying</h2>
<p>I have mixed feelings about evaluations of flyability. Each model is built by a
different person, with different building and flying skills. I’ve seen Sig Kadets
that were touchy, hard-to fly models due to poor building techniques, for example.
Likewise, the descriptions of qualities like "mildly aerobatic" are greatly
different to different people. Some people consider a model that’ll do a loop from
level flight as being very aerobatic, whilst others consider a model to be a pig unless
it’ll do the entire Master’s pattern at half-throttle (or less). </p>
<p>Corvus is not a gasbag floater. If you want one of those, put a geared 15 in an
Airtronics Oly II (I swear those things’ll thermal at midnight, on firefly light!).
Corvus is a clean, efficient airframe that will rapidly climb to thermal altitude and can
work wider lift. I believe that if you use limited flaps and/or flaperons, you can stay in
fairly narrow lift (Our older Futaba radios won’t support either flaperons or crow,
so we mainly use flaps for landing.). Corvus’s flaps will definitely cut your landing
distance significantly, but you must maintain forward stick to keep the nose down (or, if
you have a better radio than we do, use mixing).</p>
<p>Stalls are quite gentle. Excessive back pressure results in a straight-ahead nose drop
and quick recovery. The hardest part about flying it is keeping from overshooting the
runway!</p>
<p>I believe Corvus is fairly maneuverable. The rolls are slow, even at maximum throw, but
it will roll, loop, stall turn, and (barely) spin. Snaps are slow, and it is hard to do a
decent Avalanche with it. It is quite fast, strong, and much easier to fix than fiberglass
and plastic! </p>
<table border="0" cellpadding="5" width="100%">
<tr>
<td width="50%">Full size plans are available through the <a href="http://www.rcgroups.com/store/catalog">E Zone's online store.</a>
</td>
<td width="50%"><img src="http://static.rcgroups.com/articles/ezonemag/plans/corvus/corvback.jpg" width="363" height="221"><p> </td>
</tr>
</table>