Delta Dart Instructions
The Delta Dart is a good first balsa and tissue rubber powered airplane project.   It is low cost, relatively
easy/quick to build and flies well both inside and outside.   This project is clearly more complex than the
other First Flights projects and it is recommended to be done only after one is able to successfully complete
some of the other projects.
To build the Delta Dart one will need a Delta Dart kit.   These Delta Dart kits can be purchased from a number
of sources.   My preference is A C Supply (www.acsupply.com).   The
prices of these kits are $4.59 for one kit and $42.32 for 35 kits.
To build these kits I recommend the following supplies and tools:
Recommended Build Order
- 14 ¾ x 11 ¾ inch Hardboard sheet (i.e. similar to peg board but without the holes) to have a flat surface
on which to make the model.   Six pieces can be made from a ¼ inch thick 2 x 4-foot sheet.
- Masking tape
- Gel pen - these pens are better for marking on balsa.
- Single edge razor blade in a holder
- Glue stick
- White glue - Aleene’s Quick Dry Tacky Glue is preferred because it dries quickly.
- Sanding block with fine sandpaper
- Flexible ruler
- Modeling knife
- Modeling pins (i.e. any pins that are thin and sharp)
- Wing Dihedral Jig - This jig is not required but it does make forming the dihedral of the wings
easier.   The plans for this jig are attached here.
PDF of Wing Jig Plan
- # 217 – ½ Small eye screw for attaching rubber band in the back
- For indoor flying, 3/32 inch rubber is recommended. This can also be purchased from
A C Supply (www.acsupply.com).
- Getting Started
- Each student is to write their name on the plans in the appropriate spot.
- Place the plans upside down (i.e. the colored side down) on the upper portion of hardboard
- At each corner of the plans tape the plans to the construction board and in doing so make sure
to pull the plans tight without wrinkles.
- Fuselage / Vertical Fin
- The Fuselage stick is to be attached to the plans only in the rearward location as shown on the
plans.   To attach the fuselage stick to the plans apply glue from the glue stick in the
appropriate area, position the Fuselage stick on the plans and press on the Fuselage stick to
adhere it to the plans.
- To fit the first balsa stick that makes up the Vertical Fin, lay a piece of the 1/8 x ¼ inch balsa
on top of the plans.   Using the ruler and pencil, mark on the balsa where it needs to be
trimmed.   Holding the single edge razor blade holder vertically, trim the balsa stick on the
lines that you have drawn.   Cut the balsa on the lower portion of the Construction Board that
is not covered by the plans (i.e. this prevents damaging the table that one is working on).   Check
the fit of the balsa stick and adjust the fit as needed with the sanding block.   Good fitting
joints are needed to make the model strong.   Please note that it is easier to make the tips
to have a pointed shape rather than the squared off tips shown on the plans.
- Apply glue from the glue stick to the side of the fitted balsa stick that will contact the plans
(i.e. to apply the glue stick to the balsa turn the piece of balsa over, place it on the
construction board and apply the glue).   Then apply a little drop of white glue on the end that
will touch the Fuselage.   Excess white glue will result in the glued joint taking longer to
dry.   One way to limit the amount of white glue applied is to dip the tip of a toothpick in a
small puddle of white glue and use this dipped end of the toothpick to apply the glue.   Once
the glue has been applied to the fitted balsa stick, place the stick on the plans and gently press
on it to glue it in place.
- Fit the second piece of balsa that makes the Vertical Fin the same as you did the first.   When
you have this piece fitted, apply the glue from the glue stick as before.   But, you will need
to apply a small amount of white glue on both ends of the piece of balsa.   Then place it on
the plans and gently press on it to glue it in place.
- The Wing is made the same way that the Vertical Fin was made with the one exception. nbsp The white
glue is not to be put on the ends of the center balsa sticks as these surfaces will get glued when
the dihedral of the wing is set.   Also, it is recommended to fit the four outside sticks and
glue them to the plans before fitting the three sticks on the inside of the wing.
- Horizontal Tail
- The Horizontal Tail is to be made the same way that the Vertical Fin was made.
- Gluing the Wing to the Fuselage
- Trace outside of the Fuselage and the Wing with a modeling knife to cut them from the plans. nbsp Be
careful to cut just outside of the balsa and not to cut into the balsa.
- The Wing is to be glued onto the Fuselage in the position shown on the plans (i.e. be careful not to
glue the wing on backwards).   Modeling pins can be used to hold the wing in place as the glue
dries.   As a faster drying alternative to white glue, cyanoacrylate glue (i.e. gap filling super
glue) can be used.   But, it is recommended that the cyanoacrylate glue be used with supervision
or by the adult leading the class.
- Place this assembly in the Wing Dihedral Jig as shown.   Use masking tape to hold both ends of
the fuselage down in the Jig.
- Hold the Jig upside down and place a drop of glue in each of four corners where the sticks that form
the outside edge of the wing intersects the fuselage.
- Gluing the Horizontal Tail to the Fuselage
- If the glue that holds the wing to the desired dihedral angle is dry, it may be removed from the
Wing Dihedral Jig.   If not, the wing needs to stay in the jig until the glue is completely
dry.   If desired, the Horizontal Tail can be made after the Wing is glued to the Fuselage and
the glue is drying.
- Trace outside of the Horizontal Tail with a modeling knife to cut it from the plans.   Be careful
to cut just outside of the balsa and not to cut into the balsa.
- On the top of the Horizontal Tail place a drop of glue at the front, middle and back edge.   Place
the Horizontal Tail on the Fuselage per the alignment marks.   Use a modeling pin at the front
and back edge to hold the Horizontal Tail to the Fuselage as the glue dries.
- Finishing the Assembly
- Push the propeller assembly onto the front of the Fuselage.   It may be necessary to slightly
compress the front corners of the Fuselage to allow the propeller assembly to be installed.   Also,
the eyelet is to hang beneath the Fuselage.
- To attach the rubber band in the back, modify a # 217 – ½ Small eye screw by opening up the eyelet
so that it looks like the eyelet on the propeller assembly.
- Screw this modified eye screw in the bottom of the Fuselage where shown on the plans until it is
threaded all the way in and the opening faces to the rear.
- To form a rubber band motor, tie a knot with the end of the rubber strip.  Install the knotted end
on modified screw eye and the other end on the eyelet of the propeller assembly.   For indoor
flying, 3/32-inch rubber strip is recommended.   Use 1/8-inch rubber strip for outdoor flying.
- Adjusting to Fly
- Hand wind the propeller 50 turns for the first flight.
- To launch the Delta Dart hold the model between your thumb and index finger at the middle of the
Fuselage.   Let the propeller go and gently toss the model horizontally.
- In the process of test flying the Delta Dart, the propeller shaft may become bent.   A bent
propeller shaft will create a vibration when the propeller spins.   The propeller shaft can
be manually bent back to minimize this vibration.
- As the Delta Dart gets adjusted, increase the number of winds on the propeller by 50.
- To make it easier to wind up the propeller, a winding jig and hand drill can be used to wind up
the propeller.   The stretch winding technique will enable you to input more winds in the
rubber.   Lubricating the rubber band will help it last longer.   One formula
for rubber lubricant is ½ tincture of green soap and ½ glycerine.   These items can be purchased
at a drug store.
Winding Jig & Winder
Winding with the Jig
Additional information about building and flying the Delta Dart can be
found at HBCI (www.hbci.com).