                              EASTWIND II 

     This is an easily built and flown electric twin designed to
use inexpensive 05 motors and the master airscrew 3:1 gearbox.  
It is the second electric twin I've built and flown this year,
the major difference between the two being size and the use of
geared motors instead of direct drive.

     Construction uses 1/4 sq. balsa extensively, along with 7
sheets of 1/16*4*48 balsa.  Also you'll need some 1/8th aircraft
ply, one sheet of 1/4 *3 sheet balsa, and a couple of pieces of
1/4 sq. spruce.  I used regular balsa and ended with a 6 lb
airplane which flies very well and easily on the cheap car
motors.

     Using contest grade wood, the weight could be dropped as
much as 6-8 oz.

     I have a lot of time on this airframe and have used it
occasionally to carry a 35 mm camera.  It carries the extra 3/4
lb of the camera, mount, and servo with ease.  In fact you'd
hardly know it's there.

     I later installed two astro geared 05 motors along with an
additional four cells, taking it's weight to just over 7 lbs.  It
now will climb at about a 70 degree angle from takeoff until the
battery dies.

     It has no apparent vices, flies very very slowly when you
ask it to...lands easily and has scale speed at about half
throttle.

     Flight times are 6 minutes with either motor setup, 1700
cells with the astros, and 1400 cells with the 05's.

      The whole front top of the fuselages comes off for easy
battery removal, changing, or charging. The radio receiver is
installed on the fuselage floor behind the wing saddle, and the
servos right at the rear of the radio compartment.  There is
ample room for all standard components and either the 16 cell or
20 cell packs.

     The wing is easily built by printing out the airfoil
section, cutting enough slightly oversized blanks, stacking them,
gluing the corners sparingly with ca, and taping the printed
airfoil to the stack.  Cut carefully with a dremel on the inside
airfoil line.

     Cut to size the rear bottom sheeting and pin it to the
plans.  Do the same with the front sheeting.  Place all capstrips
on the bottom at this time, as well as the centre wing sheeting.
Now place the bottom spar, ribs and top spar.  Use a wax paper
covered section of your aileron stock to slightly raise the
leading edge sheeting to meet the airfoil curve.
     Slightly bevel the leading edge stock so that it fits the
curve of the front sheeting and glue in place.  This, along with
the extra front sheeting will be carved away when the wing is
removed from the board.

     Don't forget or omit the 1/16th sheer webbing.  This airfoil
is a bit thinner than some at 10 percent and should have the
webbing.

  Install the top front and rear sheeting.  NOTE THAT YOU MUST
INSTALL THE WIRING HARNESS BEFORE SHEETING THE WING CENTRE
SECTION.

     Before sheeting use masking tape to mark the positive and
negative leads coming from the wing bottom for both the motors
and the battery connector.  It'll save confusion when soldering
the motors in later on.  See the plan for wiring.

     Print out the nacelle section, and cut four blanks, using
the printout to cut out the nacelle sides.  Use 1/16th cross
grain sheeting to double the thickness to 1/8th.  This is
sufficient for an electric installation.  For glow use 3/16th
sheet might be preferable, along with the obligatory 1/4 ply
firewall.

     Use some triangle stock along the nacelle tops to allow some
carving to match the spinners.
     
     make up four motor mounts by gluing together pieces of 1/4
inch spruce so that the mount is doubled to about 1/2 inch rear
of where the motor will sit.  Drill holes here for appropriate
tie wraps to hold the motors in place.

     Now glue the motor mounts to the nacelle sides.  I used ca
for all construction in this plane, both thin and thick.

     Install the nacelle sides on the wing, careful lining up 90
degrees to the leading edge. Remember you don't need any side
thrust in an electric, 'cause you're not going to have any
flameouts.  Right?

     Use 1/4 sq balsa pieces to frame up the nacelles.  Carve the
front sections to match the spinners, after sheeting the tops
with 1/8th balsa.  Note that the nacelle bottoms are left open to
allow motor cooling.  This is very effective. I can fly both
twins back to back for several flights and barely feel any heat
in the motors.  Heat doesn't bother the astro motors, but over
time tends to weaken the 05 ferrites.


     The Fuselage is an easy build as well. Print out the 1/4
balsa sheet "keel" which is designed to carry the load of both
the wheels and the battery pack, yet keep weight to a minimum. 
It seems to work, as I have never had any breakage in this model,
despite some harder than planned landings.  Cut these pieces 
from 1/4 sheet balsa.

     Build up both sides using 1/4 sq. balsa.  Both sides are
then sheeted to just aft of the wing saddle using 1/16th sheet. 
This is not really necessary but I like to have something to grab
omto when I pick the model up by the fuselage.

     Glue 1/4 in sq. spruce rails along the bottom insides of the
"keel" area to support the landing gear plate and the battery
plate.  Two cross formers of 1/4 spruce should be used at the
landing gear location.

     Join the sides over the plan top view using 1/4 sq. balsa
and the 1/8th aircraft ply front wing hold down.  I used two
pieces of 1/4 inch behind the hold down for a bit more security.
Place appropriate size pieces of 1/4 sq. between the fuse sides
as they taper together front and rear.  A piece of 1/4 sheet is
used to pull the nose together, along with a soft balsa block
which is carved to shape.  The bottom of the fuse is sheeted with
1/16th balsa with the grain running from side to side.  The top
rear is not sheeted.

     I cut an air cooling inlet through the bottom of the nose 
block to provide some cooling air over the speed controller which
resides right up in the nose, and an exit hole was cut in the
bottom sheeting about 4 inches or so back of the wing saddle. 
Remember, your receiver sits about there, so cut this hole back
far enough so you have room to mount the receiver.

     The whole front top of the fuselage is designed to come off
to allow battery placement.  The hatch is built up of 1/4 sheet,
with 1/4 square sides.  I had to use another section of sheet on
the hatch top to fair it into the front of the wing, carving it
to shape.

     After fitting the stab and fin, 1/4 capstrips are used along
the sides and centre of the fuselage to bring it level with the
sheeted front section for covering.

     Use hardwood blocks for the rear wing hold downs and after
drilling and tapping these install and align the wing.  Use the
wing as an aid in aligning the fin and stab.

     The stab and fin are built using the appropriate 1/4 inch
sheet and 1/4 sq balsa.

     The battery is held in place by velcro and is mounted on a
plate made of two layers of 1/16th balsa, joined cross grained. 
Smooth some thick ca on the upper layer to give the velcro
stickum some place to grab.  The plate is fastened to the 1/4 sq.
spruce rails with small screws.

     The plane is balanced at 25 percent of the constand chord
wing.  Battery placement is just as shown on the plans, but this
is one of the neat things about some electrics...the battery can
be moved forward or aft to balance the ship.

     I test flew this plane using it's original motor
configuration, two 18 turn mild modified car motors and master
airscrew 3:1 gearboxes.  Props were 10/8 on 16 cells turning 7800
rpm.  I changed to 9/8 props a bit later and found them to work
well also.  Amp draw with both was about 25. 

      Lift off occurs easily in 30-40 feet from our grass field
and flights on this setup with 1400 cells were an easy 6 minutes. 
On two occasions I got nine minutes by simply loitering at
altitude, but this was rather boring flying.

     As soon as any throttle is applied, this plane likes to
point it's nose right into the wind, typical of a lot of
taildraggers.  As soon as the tail feathers get some airflow
however, it starts to track straight.  You can make repeated
touch and goes in crosswind conditions and never see the swing
into the wind tendency until you actually stop it, at which time
it will turn it's nose in whatever direction the wind is blowing.

     I later changed to astro geared 05 motors and added four
more cells, bringing the weight to just over 7 lbs.  With 10/8
props turning 8500 the plane is much more aggressive, but still
lands slowly and easily.  Stalls are straight forward with just a
slight nose drop.

     The sound of electric twins is unique.  You can plainly hear
the prop noise, especially through a steep turn.  The sound is
very scale like.

     I am still flying the smaller original version of this plan,
with two 05 car motors direct drive on 12 cells.  This little 48
inch span plane is very aggressive and gives me repeated 6 minute
flights.  Once this summer during our fun fly, I dumped it
attempting a limbo pass.  When I picked up the pieces I thought
it was a write off, but a quick look saw the breaks were clean,
and in the absence of any fuel soaking, easily fixed.  In fact I
went to my home a short distance away, got out the ca and was
back within the hour, flying it again.

     A word about electric motor wear.  I've found that there is
virtually no wear, certainly not what I was used to while racing
elecric cars, on the ferrite 05 motors.  I have 176 flights on
the direct drive twin at this time and the brushes are hardly
broken in.  This much time in a racing scenerio would have seen
the motors chucked a long while ago.

     If you decide to do something with this plan, and have any
questions, please feel free to contact me at

nstn1183@fox.nstn.ca.
     This plan is freeware.  Should you make any changes or
improvements I'd appreciate any comments.

  cheers
 Al Eastman

     
  
