rev 10/09/07
25. Cap all exposed ribs with 1/16 x 3/16” balsa.
26. Cap all exposed spars with 1/16 x 3/8” balsa.
27. Sand until pretty!
Congratulations! The hardest part is done.
Tail
1. The two tails (feet) are built from two pieces of 1/4” balsa that just glue together. Once the glue is dry, sand tail
and rudder-vators down to achieve an aerodynamic profile.
2. Epoxy tail pieces to carbon longerons (5/16” x 25 1/4”)
Body
1. Glue the rear body spacer (1/4” balsa) to the assembled tail/longeron pieces, being careful to align the longerons
to each other (they should be parallel), and careful to align the tails for the proper “V” (they should be at a 100
degree angle). Cut a piece of 1/4” scrap balsa for the forward body spacer.
(see build picture 25 on the website)
2. Glue body sides, and middle body spacer to longerons.
(see picture 26 on website)
3. Cut out from 1” balsa front outer “chest” pieces and glue to body sides.
(see pictures 27 and 28 on website)
4. Epoxy neck pieces to “chest” pieces, using 1” balsa in between. Carbon reinforcement of neck is recommended,
either by gluing carbon strips or rods to the insides of the ply neck pieces.
(see pictures 29 and 30 on website)
5. Attach the head using 1/4” balsa and 1” balsa cut to size as needed.
(see pictures 29 and 30 on website)
6. Glue in top and bottom of head using 1/4” balsa. Sand to match curves of head profile. Plan on adding some
lead to the head ( 1 - 3 oz.) to balance the plane.
7. Make a belly tray out of 1/16” ply to cover the bottom of the body. It should be removable to facilitate battery
installation and removal. Add balsa to the body as needed.
8. Check fit of wing to body and sand as required. Drill 2 holes in upper “chest” area to facilitate the carbon wing
retainers on the leading edge of the wing. Holes can be oversized, and brass tubes can be epoxied in place once
the proper location has been established.
9. Drill 2 holes for the rear holding of the wing. Be sure the wing is properly aligned to the tail before drilling. Epoxy
in 2 blind nuts.
10. Double check alignment and fit of everything.
Covering
This is not the easiest airframe to cover, but if you use the right material and are patient, and have some covering
experience, it will go smoothly. I do not recommend Monocote, because it doesn’t stretch as much as Ultracote,
and you need the stretch for the compound curves on this bird. Ultracote or Oracover are my recommendations.
Please use transparent colors to show off all that hard work you did with the wood! You will need 3-4 rolls
depending on your color choices. I always make the top and bottom different enough to see easily at altitude, to
avoid getting mixed up while flying.
Setting up and flying
The center of gravity is marked on the plans. Elevator throws should be fairly small, or you should use lots of
exponential in programming your radio. Aileron throws should be much higher. Use as much up aileron throw as
you gear will allow. It’s a big wing. If you can mix some down flap into the ailerons, do it. Rudder throw can be
greater than the elevator throw.
Flaps - will slow the plane down, but be sure to try them at a very safe elevation first. You may need to mix in some
elevator compensation.
The Pterodactyl will fly pretty fast, especially if you are using brushless motors. I recommend keeping the speed and
acrobatics to a minimum for the first few flights. Landings should be uneventful, as long as you have grass to land
on. Keep the speed up when landing, and give yourself lots of room. It glides very well (when the flaps aren’t down).
Good Luck!
