FlyingFoam Nurf. General Assembly Instructions

Transcription

1 FlyingFoam Nurf General Assembly Instructions These instructions apply to the Nurf, an all EPP forward swept flying wing available from FlyingFoam.com. Building and operating a remote controlled aircraft involves risk. By building and flying this kit you are accepting said risks. We assume a basic level of model aviation knowledge in both building and operating our aircraft. Please seek experienced help when required. We make every effort to ensure our kits are of the highest quality, and any documentation is as accurate as we can make it at the time of writing. Due to the flexible nature of our designs there are many ways to successfully build our kits. We document what we feel is the best method for general-purpose use. Please refer to for further details. Requirements: Radio/receiver with elevon mixing 2 mini servos (We like the Hitec 82MG) Motor: 300+ watt electric power (we like 75 watts per pound of flying weight for average performance) Battery: 5000 mahr 3S lipo or mahr 4s lipo (Nurf has flown with as much as a 9000mAhr 3S) Electronic Speed Control: Match to your motor (40+ amps would not hurt) Prop: 9" for ground clearance (12" max to clear vertical stabilizer, but you might want a folder or add landing gear for ground clearance) Options: Folding prop and spinner Included: 1.3# EPP fuselage core (cut in half for easy access) 1.9# EPP wing cores (with spar slots) (6).188" carbon fiber tube spars (4) Steel joiners (pre-bent) (12ft) 5 mil lamination film (to cover the wing and fuse) (3ft) 1.7 mil lamination film (to cover/hinge the elevons) (1) 4mm coroplast vertical stab (top/bottom) (2) 2-56 Threaded rods and nylon clevis (2) Nylon control horns (2) 2-56 quick connectors (2) 1/4" Balsa elevons (1) 3/32" birch ply firewall (1) Mylar hatch Rev /21/13 1

2 .188 carbon fiber tail pin 3 wide fiberglass tape (2) Bamboo Skewers Recommended Tools/Supplies: Hobby knife with #11 blades Snap-blade knife Sanding block with medium grit ( ) paper 5 minute epoxy CA Medium and Thick Fiber-reinforced packing tape Masking tape Covering iron Rotary tool with small router bits Flat building surface 1/2 brass tube Assembly Instructions NOTE: We strongly recommend building the wing first as this will allow you to test fit the wing on the uncompleted fuselage in order to place your gear for best CG position. Wing Core Preparation 1. Start by separating the wing cores from the beds. SAVE THE BEDS - They will be used throughout Note: It is normal for the beds to stick to the cores, so be careful when separating. 2. Lightly sand the cores to remove imperfections. A sanding block with 120 grit sandpaper works well for this. 3. Use a knife to remove any flashing or excess EPP from the beds. It is important the cores lay flat in the beds, as it will help ensure building a straight wing. 4. Vacuum or use compressed air to remove all dust and remaining debris. Join The Wing Cores 5. Tape the bottom beds together with a strip of masking tape. Repeat for the top beds. 6. Glue the wing halves to the center wing section with 5-minute epoxy. Align the wing in the bottom beds and use tape to hold the joints. Apply weights to hold flat, or hold with your hands if you are not doing anything for the next 5 minutes. When the epoxy sets, remove the weights and masking tape. Rev /21/13 2

3 Spar Installation 7. The carbon fiber spars are joined at the wing panel joints with the pre-bent joiner wires that are found in the small parts bag. The spars will also be wrapped at the joint with ~1.5 of the 3 wide fiberglass tape. Start by dry fitting the joiners and spars; deburr the ends of the joiners/spars with sandpaper if required. Test fit the spars in the wing cores and adjust the joiners and spar slots as required. Once the dry fit is satisfactory use epoxy to join the carbon fiber spars with the bent wire spar joiner and wrap the spars at the joints with the fiberglass tape. 8. The spars can be glued into the EPP cores with CA glue, epoxy or 3M Spray contact adhesive. To use 3M glue, spray a medium coat of 3M into the spar slot of the cores and let dry for 5 to 10 minutes. Spray a light coat of 3M on 1 side of the glued together spar assembly and IMMEDIATELY place the spar in the spar slot in the wing core. DO NOT WAIT. The wet 3M glue will allow you to position the spar in the slot. IF YOU WAIT TOO LONG YOU WILL NOT BE ABLE TO MOVE IT!! 9. Weight the spars and wing so they remain flat in the beds while the glue dries. NOTE: Moving the wing before the glue fully dries may allow the spars to slide in the foam and result in a twisted/warped wing. 10. Repeat the process for the bottom spars. Servo Installation 10. After installation of the bottom spars you should have the wing cores in the top beds with the bottom of the wing facing up. 11. Locate the pockets for your servos (we recommend metal gear servos with the mounting ears removed). Measure 17 out along the elevon hinge line from the wing panel joint formed by the center and outer wing panels. From that mark measure forward and perpendicular from the elevon hinge line to just behind the location of the Rev /21/13 3

4 spar. This will be the outboard edge of your servo pocket. You can now mark the outlines of your servo using this mark as a guide. Make sure you keep the servo pocket behind the spar so you do not cut into it while creating the pocket. Your servo pockets should be a snug fit in the foam to ensure you minimize any excess play. Perform the same procedure for the other side of the wing. 12. To complete the wire run for the servo leads use a sharp blade and straightedge to cut a slit for the wire that extends from the servo pocket to the centerline of the wing. You may need servo extensions to complete the wire run. There should be a few inches of wire lead extending from the centerline to make it easier to plug in the servos. 13. Once you are satisfied with the dry fit of your servos you should plug them in in order to center and install the proper control horns. You can then glue the servos into the pockets. We recommend Goop type glue to secure the servos, but CA or doublesided tape will work. We also recommend using fiber-reinforced tape to cover the servo. Don t forget that you need to prime EPP with 3M 77 any time you expect tape to stick. Don t worry about cutting a slot in the tape for the servo control horn yet as we will also be covering the wing with lamination film. Make sure the servo wire is inserted in the wire run. Final Wing Preparation 14. You can round/shape the forward wing tips to your liking. We use an old CD-ROM as a template, but any object with a similar radius will work. Use a sharp blade and your preferred template to round the tips. Once rounded you can use a sanding block to sand the tip profiles to a compound curve. Rev /21/13 4

5 NOTE: Do not use too much pressure with the sanding block or you risk tearing instead of sanding. 15. Perform a final sanding of the entire wing with a sanding block and grit sand paper. This sanding will help remove the thin layer of heat-affected EPP from the hotwire process, which will help the lamination film better adhere to the surface of the foam. 16. Now is also the best time to sand and bevel your balsa elevons in order to reduce dust/debris on the bench during covering. Wing Covering 17. Once you are satisfied with the wing s finish it is time again to vacuum the wing, elevons and beds to make sure they are free of any debris. Also make sure the bench is free of any dirt/debris, as the laminating film likes to attract anything you miss. 18. Using one of the wing beds as a template, cut out four pieces of 5 mil lamination film. Make sure to cut the pieces long enough to overlap in the center of the wing. 19. With the wing facing bottom-up in the top beds position a piece of the laminating film over half the wing. There should be a few inches of overlap in the center. Use a medium-hi covering iron and start in the center of the panel and work out to the tip. Then work from the center of the panel to the center of the wing. Repeat for other side. NOTE: 5 mil lamination film will not stretch as much as some iron-on coverings. It does not wrinkle as easily, but if you start a wrinkle it is harder to iron out. Keep the covering tight with your free hand and avoid too much slack as you iron down the covering. Practicing with a small scrap of film on the foam beds is recommended. When the film goes clear under the heated covering iron you have reached the right temperature. 20. Once the bottom of the wing is covered you can place the wing in the bottom beds with the wing facing up and repeat the same process for the upper surface. NOTE: For best performance it is critical you do not impart a twist/warp in the wing while covering. Keep the wing flat in the beds as much as possible while covering; take your time; and attempt to use the same technique and heat for all four panels. Elevon Installation 21. Once the wing is covered you can cover and install the elevons. The elevons can be covered with the provided 1.7mil lamination film or your preferred tape. Whichever method you prefer, it is important that the elevons are flat after covering. 22. You can use either tape or lamination film for the hinge. We prefer the 1.7mil lamination film, but a tape such as 3M Blenderm will work. Rev /21/13 5

6 23. Once the elevons are hinged you can cut out access holes for the servo control arms; plug in the servos; and allow the arms to center. 24. The control rods should run perpendicular to the hinge line. Use a fine tip marker to mark the holes for the horns and a small drill bit to make the holes for the screws. Once the holes are marked and drilled you can install the horns. 25. With the wing flat in the top beds and the bottom of the wing facing up you can use a straight edge to ensure the bottom of the wing airfoil towards the trailing edge and the bottom of the elevon are flush. This should help set proper reflex for your maiden flight. You can now measure and bend the 2-56 control rods for the elevons. 26. There are EZ Links in the small parts bag that will allow you to bend a 90 degree angle in the control rod and attach to the servo control horn. Fuselage Prep 27. Now that the wing is complete you can tape the fuselage halves together with the rudder in place to prepare for test fit of components and CG testing. NOTE: We recommend using regular masking tape for the following steps as blue or painters masking tape does not stick well to EPP. 28. Once the fuselage is taped together you can mark the CG range on both sides of the fuselage. The recommended CG range is from the leading edge of the wing saddle to 3/8 behind the leading edge. Use a straight edge and a fine tip marker to mark this range on the bottom edge of the fuselage on both sides. 29. Place the wing in the saddle and then tape your motor, ESC and any other gear you plan to fly onboard in their approximate locations. 30. Using the tail pin as a balance bar, position the fuselage so that your forward CG marks are centered over the pin. Rev /21/13 6

7 31. You can now position your battery and reposition other components until the Nurf balances on your pin. 32. Once you are happy with the balance of the Nurf you can mark the locations of the components for reference during pocketing. You can now remove the tape and components and begin the pocketing process. NOTE: See flyingfoam.com for preferred pocketing schemes for various Nurf configurations. 33. We recommend a snap blade knife and/or a rotary tool with small router bit to complete the pocketing process. 34: Once you are happy with the fuselage pockets you can glue the two fuselage halves together with 3M 77 or a light coat of 5-minute epoxy. DO NOT glue the vertical fin in yet. It will be glued in place after the fuselage is covered. NOTE: If using 3M 77 to join the two fuselage halves together make sure you protect the pockets AND tail area from overspray. Rev /21/13 7

8 Final Fuselage Prep 35. You can now use your sanding block with grit to round the edges of the fuselage and lightly sand the surface. 36. Once sanding is complete it is time again to vacuum the cores and your bench to prepare for covering of the fuse. 37. The last step before covering the fuse is to make sure you have added your favorite fiber-reinforced tape to areas of high stress. We recommend reinforcing the wing saddle at leading edge, the firewall, and any place where the foam gets thin around the pockets. Don t forget to prime with 3M 77 and to protect from overspray. Fuselage Covering 38. Using the fuselage as a template, cut four pieces of lamination film with enough length to overlap the firewall. 39. Starting with the bottom of the fuselage, position the film so there is enough to overlap the firewall. Using your covering iron carefully apply the film to the bottom of the fuselage. NOTE: We recommend temporarily placing the tail in the tail slot while covering to help maintain correct dimensions of the fuselage. 40. Once the film is applied you can use scissors or a sharp knife to trim the film along the edges. We recommend leaving just enough film to easily roll around the corners with the covering iron. 41. Repeat this process for both sides and the top of the fuselage. Once the fuselage is covered you can use a sharp knife to cut the covering as required for access to your pockets and tail fin slots. Rev /21/13 8

9 Tail Fin Installation 42. Temporarily place the wing in the saddle with the top and bottom fin in position. Once you are happy with the fit of the both the bottom and top fin, mark the bottom fin with a pencil along the fuselage outline. Remove the bottom fin and scuff the bottom fin inside these lines. This will help the epoxy achieve a better bond. 43. Glue the bottom fin in place with 5-minute epoxy. Be careful not to glue the two fins together as the top fin is designed to be removed. NOTE: As the top fin is used to hold the wing in position it is important that you achieve a snug fit between the upper wing surface and the bottom surface of the top tail. You may need to carefully trim the corroplast to achieve best fit. 44. When the glue on the bottom tail is dry you can install the tail pin. The fuselage is already pre-cut for the pin. Make sure the wing and tails are properly inserted and mark the end of the tail pin with a black marker. While the marker is still wet you can push the pin into the hole to transfer the mark to the top fin. 45. Remove the top fin and there should be a mark transferred from the pin. Use this mark as a guide and drill a hole through the top fin with a 3/16 drill bit. 46. Insert the bamboo skewers into corrugations near the leading and trailing edge of the fin. The goal is to add stiffness to the tail. Trim to fit. NOTE: We recommend using light fiberglass, CA hinges or other thin material to glue doublers on either side of the top fin where the tail pin hole is located. This will help keep the hole from becoming enlarged over time. Rev /21/13 9

10 Final Assembly 46. Lamination film will hold plastic compatible paint very well. You can also use trim tape and/or colored packing tape to add color to the design. NOTE: To maintain visual line of site and proper orientation it is highly recommended to use a very high contrast color scheme. 47. Install your motor, speed control and receiver per the manufacturer s instructions. For your maiden flight we recommend replacing any expensive cameras or similar equipment with ballast; once the plane is properly tested and trimmed you can replace the ballast with your real equipment and have fun. 48. Plug in the ailerons and install the wing and check for proper travel and direction. Low High Aileron 1/4-3/8 1/2 3/4 Elevator 1/4-3/8 1/2-3/4 49. To check the center of gravity you can use a tube or rod (a pencil works) under the fuse as a balance bar, or the tips of your fingers just behind the leading edge of the wing where it meets the fuse. NOTE: Since the Nurf is a flying wing it has a fairly tight CG range and it is much easier to maiden with the CG at the leading edge of the wing. You can slowly move the CG back as you get comfortable with the plane. Maiden Flight NOTE: It s beyond the scope of these assembly instructions to teach you how to fly. Please adhere to AMA safety regulations, use common sense and have fun. 50. During the maiden flight we recommend that the plane be trimmed so that you can fly straight and level at half throttle from one side of the field to the other without pilot corrections. Rev /21/13 10

11 NOTE. The Nurf has 4 degrees of thrust line built into the motor mount and we have found it works well with several different motors and payload configurations. However, to get best performance it is good to check your configuration. Even if you plan to fly with an IMU our other auto stabilization method there is no substitute for a wellbalanced and trimmed aircraft. 51. Once you have the aircraft properly trimmed for cruise you can check your thrust angle by flying straight and level at a comfortable cruise speed and slowly move the throttle setting to full throttle. There should be very little movement of the nose if the thrust line is correct. If you see large pitch changes during this test then land and check your CG. If your CG is correct then you may need to add washers to the motor mount to adjust thrust line: If the Nurf is pitching nose-up when throttle is applied then add washers behind the bottom two bolts of your X-mount. If it is pitching nose-down then add washers behind the top two bolts of your X-mount. We recommend one washer on each bolt be added to the stack until the thrust line is correct. Perform flight tests as described above and repeat until you are happy with the results. Care and Feeding Make sure you pre-flight the aircraft before every flight. The Nurf was designed to take abuse, but you can still break it. The good news is it s also easy to repair. During our testing we found the wing tends to outlast the fuselage by a wide margin. In particular, we have found that lamination film is very strong, but once it fails it likes to run. So check for signs of cracks in the covering as well as the foam. We recommend repairs with Goop or epoxy followed by fiber-reinforced tape. Don t forget the Nurf was designed to be hacked. We love feedback especially pictures/videos of your creations. We will maintain notes on tips and tricks, as well as a gallery of images and videos at flyingfoam.com. Enjoy! Team FlyingFoam. Building and operating a remote controlled aircraft involves risk. By building and flying this kit you are accepting said risks. We assume a basic level of model aviation knowledge in both building and operating our aircraft. Please seek experienced help when required. We make every effort to ensure our kits are of the highest quality, and any documentation is as accurate as we can make it at the time of writing. Due to the flexible nature of our designs there are many ways to successfully build our kits. We document what we feel is the best method for general-purpose use. Please refer to for further details. Rev /21/13 11