Neo Mini Aerospace Speciality Products Page 5
come out near the rear centering ring and
allow to dry completely. After the mount is dry, thread the
shock cord back through the engine mount so that the cord is inside the body tube
.
Body Tube
Glue Inside of Tube
Apply Glue to
outside
of this Centering Ring
Body Tube
End of Centering Ring
Even with End of Body Tube
Engine Mount
Shock
Cord
Figure I
Figure J
⎕
5) Locate the set of fins. Carefully remove the fins from the laser cut sheets of wood. You may need
to separate them from the surrounding wood with your hobby knife.
It is not required, but if desired, you may round or airfoil the leading and trailing edges of the fins. This
will make the fins more aerodynamic and allow your rocket to fly higher than it would if you just left
the fin edges square (the airfoiled, or “teardrop” shaped fin is more aerodynamic than a fin that is just
rounded). In either case, be sure to keep the root edges (the edges that will be glued to the body and
engine tubes) square. The tip edge may be kept square or rounded. See Figures K and L (the left
example in Figure L is a rounded fin, the right example is an airfoiled fin).
Using medium grit
sandpaper, shape each fin as desired - a sanding block may be used for this. If you don't have a
sanding block, lay the sandpaper down on a flat surface and move the edges of the fin against the
sandpaper. Be careful not to remove too much wood at one time - roughly shape one side then turn
the fin over and do the same on the other side. Continue this procedure with the medium and then
fine sandpaper to further shape and smooth the fins until you are satisfied with their appearance.
Repeat with extra fine sandpaper if desired.
Tip
Edge
Trailing Edge
Leading
Edge
Root
Edges
Leading Edges
Trailing Edges
End
!
Views
!
of Fins
Body Tube
Engine Tube
Fin
Figure K
Figure L
Figure M
⎕
6) You will now attach the fins to the body tube. We like to use the "Double - Glue Joint" method - it
makes a strong bond and it's easy to attach the fins without having to hold them in place for a long
time while the glue dries.
One fin at a time, apply a thin layer of glue to the root edge of each fin and also to the body tube
along the fin line and red engine tube where the fin will be attached and allow the glue to dry (you can
apply the glue to the root edges of the fins then lightly press them on the tubes to apply the glue to
the tubes - remove any excess glue with your finger if you put too much on). You can set the fin on a
piece of wax paper or just over the edge of a table while the glue dries - it will just take a few minutes
until the glue is dry to the touch.
