Balsa Glider Construction

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Balsa Glider Construction
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Balsa Wood

• Very high strength to weight ratio.
• Easy to cut and sand
• Grainy
• Available in strips, sheets, or blocks
• Not very durable for a fuselage spruce is better.

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Glider Components

• Fuselage
• Wings
• Horizontal Stabilizer
• Vertical Tail (or Stabilizer)
• Nose Weight

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Familiarize yourself with the plan

• Components
• Dimensions
• Materials
• Outlines vs. Cuts

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Building on a single sheet
Notice the grain direction Always spanwise!
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Marking the fuselage
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Choosing a Wing Planform

• Elliptical wings might be great for full size
  aircraft, but they are very challenging for small
  gliders.
• Straight leading edges tend to work well for
  small gliders.

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Cut out all of the pieces

• Cut the wing with extra span if material allows.
  (See later note for reason)
• Cut out stabilizers and sand leading and trailing
  edges with minimal rounding.

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Shaping the Wing Profile

• The leading edge should have minimal rounding.
• The trailing edge needs to have a taper on the
  top only.
• Use a sanding block and the edge of a surface for
  uniform sanding.

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Adding the wing

• Center the wing on the fuselage.
• Glue it on straight and square to the fuselage
  this is critical.

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Making a strong bond

• Traditional method of lots of glue on an edge
  then stick it together is weak.
• Light bond with reinforcing fillets increases the
  glue surface area and thus the strength of the
  bond.

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One Piece Stabilizer

• Cut out the wedge from the glider plan.
• Trace on to and cut out the wedge from a scrap of
  fuselage.
• Glue the wedge (not the stabilizer) to the top of
  the fuselage.
• Direction depends on tail or canard mount.

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Add the horizontal stabilizer

• One piece stabilizer
• Stronger
• Only possible if mounted somewhere away from the
  vertical stabilizer.
• Two piece stabilizer
• Weaker
• Mount anywhere else

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Check alignment

• Hold the stabilizer on the wedge and check from
  the front or back that it is parallel to the
  wing.
• If not, sand the wedge slightly and recheck.

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Glue the Stabilizer

• Glue to the TOP of the fuselage.
• Align the lowest edge with the end of the wedge
  so it contacts the fuselage.

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Two Piece Stabilizer

• Cut out the wedge from the glider plan.
• Trace an angled line onto the side of the
  fuselage.
• Direction depends on tail or canard mount.

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Check alignment

• Cut the stabilizer in two.
• Doing one side at a time
• Glue one half to each side.

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Glue the Stabilizer

• Glue to the SIDE of the fuselage.
• Make certain that each half is straight and
  square to the fuselage.

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Balance the Glider

• Place a pencil on the table top and put the
  glider on top of it with the C.G. directly over
  the pencil.
• Add clay to the nose until the glider balances at
  the C.G.

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Balance the Glider

• Hold the glider on fingertips placed at the nose
  and the tail.
• Add clay to the wingtips until the glider
  balances at the fuselage.