Stingray A micro RC Pusher Jet for 12 mm direct drive motors. Designed by: Ethan, Aaron, and David Payne BlueSkyRC.com Laser Cut by: JTECH Laser (http://jtechlaser.com/) General Information Though this is a simple kit to build, it does require an experienced pilot to fly it this is not a beginner s plane. Once assembled you can put this plane in a 15 x 15 x 5 inch box and take it on road trips with you. Fly it fast or slow, you always have responsive controls due to the prop wash and air flow over the control surfaces. Enjoy the Stingray. Build Skill Level: Beginner Pilot Skill Level: Advanced Wing Span: 14 (35.56 cm) Length: 14.5 (36.83 cm) Height: 4.5 (11.43 cm) Weight (with battery): 3.5 oz (101 g) Motor: 12mm Brushless (in runner)* Heat Sink: 12 mm heat sink (as part of mount) Speed Controller: T-Bird 9 Brushless ESC* Propeller: 3020 3030 (1.5mm wobbly adapter) Battery: 2 cell Lipo 450 mah (Etec) Receiver: GWS 4 channel (horizontal pins) Servos: 2 micro servos 6 gram or less** *Though this kit can be built with a GWS brushed motor, a 12mm Brushless is highly recommended. **This kit requires wing mixing.
BlueSkyRC.com - Stingray Page 2 of 8 Contents of Kit 1 Laser cut 6mm Depron Body 1 Laser cut 6mm Depron vertical stabilizer 2 Laser cut 6mm Depron elevons 1 0.32 control wire 2 Laser cut 1/32 plywood elevon control horns 1 Laser cut 1/32 plywood motor mount 1 Strip of hinge material Tools and Supplies Foam Safe C/A glue (or foam safe glue) Slow drying foam glue (for hinges) Hobby Knife (Exacto #11 blades recommended) Metal straight edge Wire cutters & pliers (for cutting and forming control wires) Clear or Colored Packing Tape (Henkel Crystal Clear works great) Pencil or Pen The following items are not required but are recommended: Foam Safe Paint (to make it pretty go very light) Shoe Goo brand Adhesive & Sealant (for mounting heat sink to plywood motor mount) C/A accelerator Building Instructions 1. Using the metal straight edge or a ruler score or indent the areas of the nose that will be bent (if not already done). This will allow the stiff depron to bend much easier without cracking. IMPORTANT: Before bending fully, apply packing tape only to the nose in the areas that will be folded this will create a tough outer skin for the folded areas of the nose and cockpit area (if not already done). 2. Cut or sand a 45 degree angle on the bottom leading edge of each elevon control surface. Make sure you angle the bottom edge one for each side of the wing. The top edge of the wing and the elevon should align allowing for the elevon to swing up and down. 3. Hinge the elevon control surfaces. This may be accomplished by using the hinge material provided or using hinge tape (not included). Using the C/A hinge method cut 6 pieces from the hinge strip each ¾ long (3 for each elevon). Cut evenly spaced slits in the upper edge of the elevon (wide enough for the C/A
BlueSkyRC.com - Stingray Page 3 of 8 hinge). Test fit the hinges in the elevon before gluing. Glue the hinges into each elevon using foam safe C/A or a good foam safe glue (do not attach elevons to the plane yet). 4. Lay the elevon over the wing where it will be attached. Using a pen or pencil, mark on either side of the C/A hinges on the top edge of the wing. These marks will guide you for cutting hinge slits on the trailing edge of the wing. Cut the hinge slits in the trailing edge of the wing near the top of the wing and angled down into the meat of the depron. Test fit the 3 hinges and elevon into the wing before gluing the elevon hinges into the wing. 5. After test fitting the elevons into the wings, use a slow drying glue on the hinges that will be slid into the back of the wing. This will give you time to adjust and fit the elevon as needed before the glue dries. GWS tube glue works great for setting the hinges into the wings. You do not want any gap between the wing and the elevon, but it should swing without any resistance. 6. Tape the leading and trailing edge of the prop canyon (center of the wing). This will make the prop more efficient by reducing the drag in and around the prop canyon. Cut 1 wide strips from the 2 packing tape roll. When taping all edges, provide a loose bubble so that the planes edges are rounded by the tape and not made blunt. You may also want to tape the leading edge of the vertical stabilizer at this point. IMPORTANT: other areas of the wing will be taped later after the receiver and equipment are installed.
BlueSkyRC.com - Stingray Page 4 of 8 7. Add some color. At this point you may wish to add a little color to your plane. Only use paint that will not melt depron or other foams. Keep in mind paint will add weight to your plane and may affect flying. If adding any paint, it is a good idea to use contrasting colors between the top and bottom of the plane. 8. Plywood motor mount attach the 1/32 plywood motor mount just in front of and center to the prop canyon using foam safe C/A. You may want to cut and lift any extra tape that might lie directly under the plywood mount to ensure a good glue connection between the plywood mount and the foam.
BlueSkyRC.com - Stingray Page 5 of 8 9. Nose / Canopy test fit the nose / canopy flap into the two slots in the top of the wing. After making slight bending adjustments and having the flaps flush to the bottom of the wing, apply foam safe C/A to the bottom slots to secure the nose / canopy in place. 10. Prepare the motor place the round heat sink over the 12mm motor. The heat sink will act as part of the motor mount and hold the motor to the wing. After centering the heat sink on the body of the motor, you may want to apply a drop of glue to secure the motor to the heat sink (if it slides or spins in the heat sink mount, this is not good). 11. Mounting the motor mark the center of the plywood motor mount with a pencil to serve as a guide when mounting the motor to the wing. Apply Shoe Goo brand glue to the aluminum base of the heat sink, and then align the motor on the plywood and press it to the plywood mount firmly. You may want to set the plane on a flat surface and place an object (for weight) on top of the motor while the glue sets. IMPORTANT: DO NOT USE SHOE GOO ON ANY PARTS OF THE FOAM AS IT WILL MELT DEPRON AND FOAM. Shoe Goo is used because it sticks very well to the aluminum as well as the plywood. It does not become brittle and will not crack like C/A or Epoxy. If for some reason you need to remove the motor, it can be twisted off the mount with pliers then reapplied with Shoe Goo again as needed. Note: even though a brushed motor is shown, a brushless model is highly recommended. 12. Mounting servos place the wing on a flat surface. Lay the servo on it s side with the bottom facing the motor and the top facing out the side of the plane. Place the servo about ½ inch away from the corner of the prop canyon. The servo arm should be closest to the elevon. With a pen, trace the servo to the top of the wing. It is best to cut the servo hole so it will be a tight fit cut on the inside of the lines. Make sure you cut enough room around the servo control arm area so they will swing free without touching the
BlueSkyRC.com - Stingray Page 6 of 8 foam. Test fit the servo and attach the servo control arms. Apply packing tape to the bottom of the wing coving the servo hole and helping to secure the servo in place. You may also want to seal the servo on top with white tacky glue around the servo edges. Make sure both servos are placed evenly to each other creating balance to the plane. 13. Elevon control horns take the 0.32 wire (supplied) and lay it over the wing from the servo control horn back over and resting on top of the elevon. Mark with a pen just behind the hinge line on the top of the elevon where the wire rests this will be where the elevon control horn will go. Measure it carefully and mark the other elevon in the exact same spot on the other side of the wing. Rest the plane on a flat surface and slit the elevon with your hobby knife to the size of the base of the control horn. Test fit it and glue it in with C/A. The control horn will probably end up near the center of the elevon. Make sure to make the slit close to the hinge line (maybe 1/8 inch way from the hinge). When the glue has dried cut and connect the 0.32 wire to fit between the servo and elevon control horn. Using a Z bend at one end of the wire and Dubro micro E/Z Connects attach the control wire to the wing as show below. 14. Vertical Stabilizer at this point we are ready to attach the stabilizer to the wing. Test fit the stabilizer then using foam safe C/A attach it to the wing. Make sure the stabilizer goes on square to the surface of the wing.
BlueSkyRC.com - Stingray Page 7 of 8 15. Receiver and Speed Controller at this point we are just about done. Attach the motor wires to the Electronic Speed Controller (ESC) then attach the ESC and servo data wires to your Receiver (Rx). The battery will slide in the curve of the nose and should fit snug (you may add Velcro if you need but usually not required. Test the direction of the servos and wing mixing before sliding the Rx into the body ensure that the control surfaces move the right directions. Some people like to cut out the foam on the top of the canopy to hold the Rx this works well if there is not enough room to slide it under the canopy and should hold it snug to the plane. Shove all the wires in tight ensure that that servo wires will not fall into the prop and that they are tight. The Center of Gravity (CG) should be about 1 inch in front of the motor when balanced. 16. Tape the wing edges using 1 wide strips of packing tape. You might be asking what to do I do with the Rx antenna? If you don t use a micro antenna, a common way is to pop a hole through the bottom of the wing where the Rx rests in the canopy, run the antenna out the small hole and tape it out to the nose of the plane. The next step is to bubble tape on leading edge of the wings down both sides the same way you taped the leading edge of the vertical stabilizer and prop canyon edges making a nice round edge to the wings. This will add both strength and durability to the leading edge of the wing and also hold the antenna wire along the side of the plane well away from the danger of the propeller. The tape and antenna wire should end where the wings meets the elevons. 17. Flight check and control surface throws. The nature of this air plane is very maneuverable and stable the fact that the prop wash rushes over the control surfaces provide great control at both high and low flight speeds. This being the case, it is not required to have a lot of control surface throws. Slight throws are best to start with until you get the hang of the plane. When you bump them up this thing will roll faster than you can count. Adjusting the max throws to ½ up and ½ down from center is probably more than enough. Using Exponential or Dual Rates on your Transmitter (Tx) is also a nice feature.
BlueSkyRC.com - Stingray Page 8 of 8 Your First Flight You now have completed your Stingray and are probably itching to fly it. Best to start on a calm day with no wind or just a slight breeze until you are used to flying the Stingray. Always double check your control surfaces making sure they are correctly setup with wing mixing. You may want to add few clicks of up trim just for the launch. Hand launching is quite easy and a strong throw is not required. Apply ¾ throttle (full throttle for brushed motor) and hold it out to your side with your thumb on top and fingers under edge of the wing and gently guide it side armed into the direction you would like to launch (into the breeze). Quickly put both hands on your Tx and you are flying. For your first flights fly at about three mistakes high until you get used to the quick handling of the Stingray. You will be hand catching it inverted in no time. ;) Recommended Setup The following is the setup enjoyed by several of the people that helped to prototype and test the Stingray. The item that will greatly increase the level of fun with your Stingray is a good 12mm brushless motor. Motor: Medusa 12mm 5300 KV (with GWS 3020 prop & 1.5mm wobbly prop adapter) Battery: Etec 2 cell Lipo 450 mah (sometimes 3 cells if you are feeling a bit lucky) ESC: Castle Creations T-Bird 9 Rx: Castle Creations Berge 4L micro stamp (or a GWS Pico 4) Servos: 3.6 gram to 6 gram micro servos Special Thanks Thanks to my sons who drew up and inspired the first version of the Stingray and kept pestering me to put some remote control stuff in that dad! Thanks to Russell Carlson, Tom Mansell, Fernando Morais, Jay Payne, Rich Rugg, and others at the Nichols Park that have helped test and fly the prototypes. Thanks to James Wagoner from JTECH Laser (http://jtechlaser.com/) for helping setup and laser cut this kit.