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General Notes
Cover the plans with wax paper or plastic kitchen wrap to keep the structure from sticking to them. Hold parts in place over the
plans with pins, but do not push the pin through the balsa pieces
Use Sig Bond or Sig-Ment for balsa wood joints.
Don't use loose scraps of sandpaper. Always glue it to a block. A 4" piece of 1" x 2" lumber makes a good sanding block.
Fuselage
Build 2 fuselage side frames from 3/32" square at the same time directly over the plans. Separate the two frames with a razor
blade when the cement is dry.
• Build one Bulkhead B5 over the plans and cut 4 additional 3/32" square spacer pieces to match the width of B5. Working
over the top view of the fuselage, cement B5 and the 4 spacers between the side frames. Carefully pull the tail ends of
the sides together and insert the 3/32" square spacers cut to the proper length.
• Crack the sides just in front of B5, pull them together at the nose, and cement B1 in place. Complete the nose structure
as shown on the plans and then thoroughly coat the 4 cracked places with cement. Don't forget the small pieces of 1/16"
square shown on the sides of B2. Sandpaper them to a smooth curve to round out the rear of the cowling.
• Cover the cowling area with the heavy paper provided. Use the pattern from the instruction sheet to cut out the top half.
Cement the paper in place and trim away the overhang. Cut the bottom half to approximate fit and pre-bend it by
carefully shaping it over a round pencil. After the cement is dry and the excess paper is trimmed, sandpaper the front
surface of B1 flat.
• Add the supports for the rear rubber peg and other small fuselage detail.
• If you are inexperienced at covering with Japanese tissue, omit the 1/16" square stringers from the sides and top of the
fuselage. Covering will be much easier and can be done in larger pieces.
Landing Gear
• Sandwich the landing gear wire between the 2 pieces of 1/16" x 3/8" over the pattern on the plans. Before the glue dries
completely, clamp the assembly tightly between two flat surfaces so the wire is actually imbedded in the wood. Cement
the completed assembly into the fuselarge, glueing it thoroughly wherever it touches the framework. Add the 1/16" x 3/8"
reinforcements.
• Make a tailwheel assembly, cement in place, and bind with a few turns of thread.
Noseblock
• First, cement together the Laminating Jig as shown on the plans. Use a pin to pierce holes in two N1s, N2 and the
square cutout from B1. Coat the mating surfaces with cement and slide pieces on the projecting wire of the jig, being
careful not to bend the wire. Let the wire locate the pieces - don't force.
• When the glue has partially set, carefully push a couple of pins into the stack and twist the noseblock off the jig. Don't let
the assembly dry on the jig. It may stick there permanently. Plug the nose block into the fuselage while sandpapering
to the finished shape so it will match the cowling perfectly. Enlarge the shaft hole with a nail and cement eyelets in place.
Do not cement the noseblock to the fuselage.
Wheels And Pants
• Laminate the wheels and pants one at a time on the jig, in the same way as you did the noseblock. Sandpaper to tht
finished shape when the glue is dry. Cement the eyelets in the wheels last.
• Complete the landing gear as shown on the plans. Thoroughly cement the 1/16" x 1/4" struts to the landing gear wire and
pants - not to the fuselage. Two wraps of tissue will help hold the struts to the wire.
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Tail Surfaces
• Build the fin and stabilizer over the plans. Thoroughly soak the strips which must be bent, in warm water. Then bend to
the correct shape over the plans, holding with lots of pins, close together. Allow to dry before cementing the other pieces
in place.
Wing
• Begin the wing by cutting 4 pieces of 1/16" x 1/8" to the length shown on the plans. Make all 4 exactly the same length
and pin securely to the plans. Then build both wing halves carefully fitted against, but not cemented to these 4 center
section pieces. Each completed wing half can be removed from the plans for sandpapering. But do not move the center
section pieces.
• You are now ready to fasten the wing panels together. Use small blocks of 1" x 2" lumber, or something similar, to prop
each wing tip 1 1/2" above the plans. Be sure the wings are not twisted during this operation. Now lightly cement each
wing half to the ends of all the center section pieces except the one at the leading edge. That one is just for assembly
help - not part of the finished wing. When these joints are dry, cement 2 pieces of 1/16" square into the notches in the top
of the ribs R1. Allow to dry. Now re-glue all center section joints with another coat. Allow to dry completely before lifting
your finished wing from the plans.
Covering
• Cover all structures with light colored Japanese Tissue. Use clear dope to attach paper to the framework at the outside
edges. Rounded surfaces must be covered in small sections. The fuselage covering may be shrunk with water spray and
doped. The wing and tail surfaces are best not sprayed or doped because they may warp and twist. The paper will
tighten over a period of time, anyway, because of changes in the weather. Dark colored tissue trim and plastic windows
are applied to the completely assembled model.
Assembly
• Never cement parts to the tissue covering. Always cut and peel away a small section of tissue to expose the bare wood.
• Cement the fin to the stabilizer as shown. Then cut a slot in the fuselage top covering to let the front half of the fin slide
into the fuselage. Then slide the stabilizer onto the rear of the fuselage and cement. Do not forget the 1/16" x 1/8" x
1/8" incidence block under the rear edge of the stabilizer. Note that the front edges of the fin and stabilizer are not
cemented to the fuselage at this time.
• Attach the wing to the fuselage with spots of glue at the intersection of the wing and fuselage members.
• Make 2 sets of wing struts over the plans. Then trim to an exact fit. Do not twist the wings by using poorly fitted struts.
Instead, carefully tailor the strut lengths so they hold the wing in an untwisted position.
Windshield And Windows
• Cut out the windshield from clear plastic using the pattern on this sheet. With the front and center of the winshield
approximately in place, tuck the ears of the windshield under the wing and the rounded projections on the front of the
cabin frame. Use large tabs of tape to hold the plastic to the sides of the fuselage. Allow the windshiel to assume a
natural fit. Attach the top edges to the top surface of the wing cutout with narrow strips of Scotch tape.
• Then, one side at a time, cement the plastic to the triangular side window frames only. The plastic is not cemented to the
1/16" square V-struts or the cowling. Trim away extra plastic when the cement is dry.
• Dope Japanese tissue over the window frame cutouts on this sheet and then cut them out. Be sure to make a right and
one left. Cut side windows from clear plastic and carefully cement to the frames. Then neatly cement these assemblies in
place on the fuselage.
• Slide the propeller shaft through the noseblock, bead, and propeller, with rounded boss of the propeller next to the bead.
Bend over the projecting end of the shaft as sharply as possible.
• Tie ends of rubber strand with a square knot. Wet the knot with water before pulling it tight. Hook the rubber band over
the prop shaft, drop the rubber into the fuselage, and slide the dowel throught the loop at the rear end.
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FLYING YOUR SIG CLASSIC
Now you are ready to fly your plane, and FLYING is what the Sig Classic models are designed for. Most models as realistic
looking as your Classic make poor flyers. They're often tricky to adjust and clumsy in the air. But Sig's Classic kits give you
three important features that assure you of successful flights:
1. A PROVEN flyable design.
2. A reliable way to make flight adjustments.
3. Complete flying instructions.
Read and follow these instructions carefully. They are the key to satisfying flying.
Testing And Adjusting
You have invested a lot of time and effort in building your model, don't waste it all now with careless testing. Most models fail to
fly because of poor adjustment, not poor craftsmanship. Be as careful in your testing as you were in your building.
Every model is a little different and needs its own special set of adjustments. Contest winning flyers make dozens, even
hundreds, of test flights "trimming" a model for best performance. So don't give up if your first flights aren't perfect.
Preflight Preparations
Before you leave the workshop for the flying field, take these important steps.
Looking from the front of the model, check that the bottom of the wing and tail
surfaces are flat - not twisted. Sight down the center line of the fuselage as shown
in the drawing. Right and left wing should look alike; you shouldn't see the top of
one wing and the bottom of the other. The fin should point straight ahead, and the
stabilizer should be flat. (This does not mean that the stabilizer and the wing sit on
the fuselage at the same angle. The wing will be tilted upward more than the tail).
A model can be made to fly with twisted surfaces, but it's confusing to adjust and
if the warps change from day to day, you can't detect it. The drawing shows how
a surface can be straightened by twisting it in the desired direction while holding
it under a heat lamp or other electric heater. Work with it until it is as flat as
possible. If your wing has struts, loosen them before bending and re-cement
them afterward.
The correct "Balance Point" for your ship is shown on the plans. Mark this point on
the bottom surface of each wing. When supporting your plane on your finger tips at
these points, the fuselage should hang level. See the drawing. Add weight to the
nose or tail until it DOES hang level. Don't be afraid to add the necessary weight.
CORRECT BALANCE IS MORE IMPORTANT THAN LIGHT WEIGHT.
Modeling clay makes handy balancing weight - it can be pressed permanently in
any corner. Wire solder or BB shot can be used by cementing in place.
If one blade of your propeller always swings to the bottom, a tiny smear of clay on the other tip will improve the prop's balance
and reduce vibration.
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Power-Off Tests
A rubber-powered model is adjusted in
two steps. First, the tail surfaces are
adjusted to produce a good glide. Then
the propeller assembly is adjusted to
give a smooth, powered flight. Wait for a
calm day.
Begin by gliding the model from your hand into a patch of tall grass. Grasp the ship by the fuselage near the balance point, and
aim the nose at a spot on the ground about twenty feet in front of you. Launch the ship forward about the way you would a
paper dart airplane, nose down.
Your goal is a steady glide to the ground, moving at a CONSTANT SPEED, and travelling straight ahead or turning gently. You
will find the trick is to launch the model at its natural speed and glide angle. If the glide is poor, it can mean that the ship needs
adjustment or that you need more launching practice. So try several launches before deciding on adjustment changes. When
your ship acts the same way on each launch, you can be pretty sure that you are seeing its true characteristics, and not just a
poor launch.
Stalling
If your plane noses up, LOSES SPEED, and then falls clumsily or dives,
that is a STALL. To cure a stall, adjust the angle of the stabilizer by
changing the thickness of the incidence block under it. Lower the front
edge or raise the rear edge. See drawing. But make SMALL changes 1/32" at a time. If a change of more than 1/16" is needed, go back and
perform the Preflight checks again. It's likely your Classic is incorrectly
balanced (tail-heavy) or the surfaces are warped.
Diving
A model that darts quickly into the ground without swooping or stalling,
is diving. The dive can be cured by adjusting the stabilizer in the
direction shown in figure 5 (in 1/32" steps). Here again, don't change
the height of the incidence block more than 1/16" without first rechecking the Pre-flight steps. Warps or nose-heaviness may be causing
the dive.
Turning
A plane that glides in a straight line takes a lot of flying space and a lot of
chasing, so it's best to adjust the glide for a slight turn. The plans for your
model will tell which direction.
The size and direction of the glide circle can be controlled by adjusting the
fin. The drawing shows adjustment for a right turn. Moving the fin opposite,
of course, gives left turn.
Small changes in fin setting can be made by bending the surface. But if more than 1/32" or so of change is required, cut the fin
loose and re-cement it at the desired angle. When the glide is smooth and steady, you are ready to go on to powered tests.
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Power-On Flight
ALL ADJUSTMENTS TO THE "WOUND UP" PART OF THE FLIGHT ARE MADE BY POINTING THE PROPELLER AND
NOSEBLOCK IN THE DIRECTION YOU WANT THE PLANE TO GO. This kind of adjustment affects only the powered flight,
and will not upset the glide pattern you have developed.
Now - wind the propeller 150 turns and launch your Classic into the wind
with the same motion you used in glide testing. The model should cruise
steadily forward, turning in the desired direction, and gaining or loosing
altitude gently.
If your ship tries to climb, but loses speed and stalls, point the propeller
downward by slipping a scrap of 1/32" balsa or a paper book match
between the top of the noseblock and the front of the fuselage. The wedge
is called a "shim" and the adjustment is called "downthrust". Downthrust is
illustrated in the drawing.
It's not likely that your plane will dive on first power flights, but if it should, put the shim at the bottom of the noseblock, tipping
the propeller upward (upthrust).
Downthrust is the "magic adjustment" that can make experts out of beginners. Learning to use it is the most important part of
your test program.
Increase or decrease the amount of downthrust (by changing the thickness of the shim behind the noseblock) until power flights
are smooth and free of stalling with 150 winds in the motor. Don't wind the motor any tighter until the lower-powered flights are
under control.
Power-On Turns
Because of the effects of the rotating propeller, models usually turn
better in one direction than the other. Your plans will say which way to
circle.
Don't circle any tighter than necessary. Circles smaller than about 50 ft.
diameter are tricky. If you have plenty of flying space, turns can be as
large as you like.
The drawing shows how side thrust is used to control power-on turning.
Making small changes, 1/32 at a time, adjust downthrust and sidethrust
together to produce smooth flights on 150 winds.
You may notice that turning to the right tends to hold the nose downright thrust acting a little like downthrust. If your plane begins to circle so
sharply that it loses altitude in a steep bank, reduce the amount of
sidethrust until the turn opens up to a safer size.
Longer, Higher Flights
When your Classic is flying smoothly with 150 turns in the motor, wind to 175 and try it. Make any necessary noseblock
adjustments, and then wind to 200, and so on. The safe number of turns that your motor will stand is shown below.
Rubber Motor Winding Chart
Length of Loop 1/4" 10 11 12 13 14 15 16
Safe Number of Turns
A plane's weight determines how much power it needs. If your ship is huskier than average, it may not climb, even when fully
wound. In that case, add one strand (not a complete loop) of 1/8" Sig rubber to the motor. Tie an eye (like a slip knot) in each
end. This will provide the extra horse power needed for higher climb.
Hand Wound 180 200 220 235 250 270 290
Stretch Wound 440 485 525 570 615 660 700
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Whenever you add rubber, re-balance your model as outlined in the pre-flight instructions. Additional rubber tends to make a
plane tail heavy.
Take-Offs
When your Classic has been adjusted according to instructions, it should have no trouble taking off by itself from a smooth
surface. No adjustment changes should be necessary. You may find that take-offs are better if you release the ship pointed at a
slight angle to the wind instead of headed straight into it. Experiment to find the best system.
Rubber Motor Hints
The rubber motor in your Classic kit will safely give you a whole season of flying if you stick to the chart. "Hand Wound" means
winding the propeller with your finger while the rubber is inside of the fuselage. "Stretch winding" is a more complicated twoman operation, but gives longer flights.
Before a motor can be safely stretch wound, it must be lubricated. Rub a few drops of Sig Rubber lubricant into the rubber
(AFTER the knot has been securely tied). Use just enough to make the motor barely damp. If it's too juicy, it will splatter all over
the inside of the fuselage. Next, make a strong wire hook, like a teacup hook, and lock it VERY TIGHTLY in the chuck of a hand
drill.
Then, while your helper holds the model by the rear rubber peg and the cowling, stretch the motor out the front of the model to
about twice its normal length, unhook the propeller, hook up the winder, and wind while slowly walking back toward the plane.
All the models in Sig's Classic series have been carefully designed and
flight tested to assure flying ability. Hand wound, you can expect flights of
10 to 25 seconds and stretch wound, 20 to 50 seconds. Like model
builders, some of the designs have more ability than others, but all are
proven dependable flyers.
A Classic flying model is not a ready-to-fly toy. Your skill in building and
flying DOES make a difference. So whether your flights are short or long,
you can be proud of completing a job which was successful because of
your own effort and ability.
Good Flying!
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SIG MFG. CO., INC. is totally committed to your success in both assembling and flying the Cabinaire. Should you encounter any
problem building this kit or discover any missing or damaged parts, please feel free to contact us by mail or telephone.
SIG MFG. CO., INC.
401-7 South Front Street
Montezuma, IA 50171-0520
© Copyright SIG Mfg. Co., Inc.
SIG MFG. CO., INC............Montezuma, Iowa 50171-0520
LIMIT OF LIABILITY:
The craftsmanship, attention to detail and actions of the builder/flyer of this model airplane kit will ultimately determine the
airworthiness, flight performance and safety of the finished model. SIG MFG. CO's obligation shall be to replace those parts of
the kit proven to be defective or missing. The user shall determine the suitability of the product for his or her intended use and
shall assume all risk and liability in connection therewith.
SIG MODELER S ORDERLINE: (to order parts) 1-800-247-5008
SIG MODELER S HOTLINE (for technical support) 1-641-623-0215
SIG WEB SITE www.sigmfg.com
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