SU-31 PROFILE ELECTRIC ARF ASSEMBLY MANUAL 1
TABLE OF CONTENTS Page Aeroworks Contact Information... 3 Introduction.. 4 Kit Contents... 5 Items needed to complete 6 Wing Assembly. 7 Stab Assembly. 10 Flight Control Assembly 12 Wheels and Motor Assembly. 18 Servos and Radio Installation 21 Preflight Preparation 26 2
401 Laredo Unit D Aurora, CO 80011 Phone: (303) 366-4205 Fax: (303) 366-4203 Website: www.aero-works.net E-mail: Info@aero-works.net Thank you for choosing the Aeroworks SU-31 Profile Electric ARF. We have put allot of effort into making this plane the best aerobatic model you will ever build and fly. Consideration was given to provide you with the highest quality and performance plane possible. We wish you great success in the assembly and flying of your new Aeroworks SU31. WARNING An R/C aircraft is not a toy! If misused, it can cause serious bodily harm and property damage. Fly only in open areas, and AMA (Academy of Model Aeronautics) approved flying sites. Follow all instructions included with your plane, radio, and engine. 3
INTRODUCTION Your new SU-31 Profile Electric ARF is a highly aerobatic airplane. It is capable of all styles of flying, from gentle and stable slow flight, sport aerobatics, to full out 3D type maneuvers. We hope you enjoy building and flying your SU-31. This aircraft builds easily, quickly, and accurately due to the CAD design and LASER cutting technology. The wing, stab and fuse are pre-assembled and covered requiring only a minimum amount of gluing or drilling. The SU-31 Profile Electric ARF is transported completely assembled. This eliminates assembly time when you get to the flying field. The battery installs easily with Velcro to get you into the air quickly to enjoy high performance aerobatic flying. The SU-31 Profile Electric ARF is designed for electric motors in the 370-400 size range. A Himax Outrunner Brushless Motor (HC 2812-1200). is shown in the assembly instructions. The aircraft was test flown using a Li-polymer 3 cell, 11.1 Volt 1200 to 1320ma battery, and 11 x 4.7 APC-E propeller and has excellent performance. The final choice of motor and battery is left up to the builder. A computer radio is recommended to allow the pilot to take full advantage of the capabilities of this aerobatic aircraft. Before starting the assembly of your new SU-31 ARF, please inventory and inspect all parts and hardware for imperfections or damage. Notify AEROWORKS immediately if there are missing or damaged parts. IMPORTANT! Please read through the assembly manual carefully and follow the order of assembly before you start building the aircraft. This will help save time and eliminate any chances of building errors. INTENDED USE This plane should not be regarded as a toy. This is an aerobatic plane and is recommended for pilots who are beyond the trainer-stage and are comfortable with flying an aerobatic sport plane. WARRENTY It is important to notify Aeroworks of any damage or problems with the model immediately. If you wish to return this aircraft for any reason a 15% restock fee will be charged to the customer. In addition the customer is responsible for all return shipping cost and all prior shipping cost will not be refunded. Parts will be exchanged/replaced once the original item is returned at the owner s expense. If you have any problems, contact Aeroworks. Aeroworks cannot insure the skill of the modeler and can not influence the builder during the construction or use of this aircraft, therefore, will not be accountable for any property damage, bodily injury or death caused by this aircraft. The purchaser/operator accepts all responsibility of any and all structural or mechanical failures. 4
KIT CONTENTS SU-31 Profile Electric ARF Parts List 1. Wing assembled and covered Aileron servo bays opened up CA hinge slots pre-cut 2. 2 Ailerons covered CA hinge slots pre-cut 3. Horizontal Stabilizer and Elevator covered Elevators in place with CA hinges not glued 4. Fuselage and vertical fin assembled and covered Battery Velcro strap installed Landing gear mounts pre-drilled Rudder in place with CA hinges not glued 6. Landing gear parts 2 Main landing wire struts pre-bent 2 Main wheels 2 Wheel collars and spacers 2 Nylon wire ties 7. Control system parts with nylon R/C keepers for ailerons and elevator 4 wire pushrods 4 nylon R/C keepers 4 nylon control horns 4 easy links 2 Velcro battery pack self stick strips 11 CA hinges 8. Decal sheet 5. Rudder covered CA hinge slots pre-cut 5
Items needed to complete: Hardware: Motor, mount Recommended (Himax HC 2812-1200) Propeller Recommended (APC-E 11 x 4.7) 2 x aileron servos Recommended (Hitec HS-55 Feather) 1 x rudder servo Recommended (Hitec HS-55 Feather) 1 x elevator servo Recommended (Hitec HS-55 Feather) Speed control Recommended (Phoenix-25 amp) Servo extensions - 2 x 6 for rudder and elevator, Y harness for ailerons Receiver - Feather, Micro Recommended (4-6 channel FM) Motor and Receiver battery Recommended (Li-poly, 3 cell, 11.1 volt, 1200 1320ma) Tools: Modeling knife Electric drill and selection of bits Phillips screwdriver Flat head screwdriver Needle nose pliers Wire Cutters Punch Pins Ruler and tape measure Pen, pencil or felt tipped marker Flat building board Building squares and blocks Masking tape Clear tape (optional) Adhesives: Thin CA CA kicker (optional) 6
SU-31 PROFILE ELECTRIC ARF WING ASSEMBLY 1. Lay a 36 ruler parallel to the trailing edge of the wing. 3. Use a 90º square to mark the centerline of the wing from the leading edge to the trailing edge on the top and bottom of the wing. Servo cut outs and open bays, are on the bottom side of wing. 2. Mark the center of the trailing edge. Then mark the trailing edge of the wing 7/32 on both sides of the centerline to show where the sides of the fuse will be when the wing is centered in the fuse. 4. Use a T pin to punch several small holes through the covering on the top and bottom of the wing in a random pattern. The holes are to allow thin CA to wick into the wood on the wing center section. The holes should not extend more than 3/16 either side of the centerline. Do not punch all the way through the balsa wood. 7
5. Use building squares, wood blocks, shims, and or masking tape as necessary to accomplish the following steps for aligning the wing to the fuse. Insert the wing through the fuse. Block and tape the fuse 90º vertical on the building board. 7. Ensure the fuse edge is aligned with the fuse edge mark on the wing trailing edge on both left and right sides. 6. Ensure the trailing edge of the wing is 90º to the fuse. 8. Ensure the distance from the wing tip trailing edge to the center of the fuse tail is equal for both the left and right wings. 8
9. Ensure the wing tips are equal distance from the building board on both the left and right sides. 10. IMPORTANT: Check and recheck all measurements to ensure the wing is straight, level, and aligned square with the fuse. When you are satisfied with the alignment, tacks glue the wing to the fuse on the topside with thin CA at the leading and trailing edges and center of the fuse. Then remove the wing and fuse from the table and flow thin CA all along the wing and fuse joint on the left and right sides and on both the top and bottom. Allow the CA to wick into the holes that were punched in the wing covering. Do not use so much CA that it runs out of the joint and makes a mess on the wing or fuse. The wing assembly is now complete. 9
SU-31 PROFILE STAB ASSEMBLY 11. Lay an 18 ruler parallel to the trailing edge of the stab. 13. Use a 90º square to mark the centerline of the stab from the leading edge to the trailing edge on the top and bottom of the stab. 12. Mark the center of the trailing edge of the stab. Then mark the trailing edge of the stab 7/32 on both sides of the centerline to show where the sides of the fuse will be when the stab is centered in the fuse 14. Use a T pin to punch several small holes through the covering on the top and bottom of the stab in a random pattern. The holes are to allow thin CA to wick into the wood on the stab center section. The holes should not extend more than 3/16 either side of the centerline. Do not punch all the way through the balsa wood. 10
15. Use building squares, wood blocks, shims, and or masking tape as necessary to accomplish the following steps for aligning the stab to the wing and fuse. Insert the stab into the fuse. Ensure the trailing edge of the stab is 90º to the fuse. 17. IMPORTANT: Check and recheck all measurements to ensure the stab is straight, level, and aligned square with the wing and fuse. When you are satisfied with the alignment, tack glue the stab to the fuse on the topside with thin CA at the leading and trailing edges. Then remove the fuse from the table and flow thin CA all along the stab and fuse joint on the left and right sides on both the top and bottom. Allow the CA to wick into the holes that were punched in the stab covering. Do not use so much CA that it runs out of the joint and makes a mess on the stab or fuse. The stab assembly is now complete. 16. Ensure the distance from the wing tip trailing edge to the tip of the stab trailing edge is equal for both the left and right wings. Ensure the stab is level to the wing when viewed from the front and rear of the fuse. 11
SU-31 PROFILE ELECTRIC ARF FLIGHT CONTROL ASSEMBLY 18. Locate the 4 control horns and 11 CA hinges pictured below. 20. Center control horn over mark and in the center of the balsa aileron doubler. Mark the location of the two control horn mounting pins. Ensure the control rod linkage holes in the top of the control horn line up with the leading edge of the aileron. The control rod linkage holes in top of control horn should be centered on aileron hinge line. 19. Lay out both ailerons with the leading edges facing toward you and root end to root end, as they would be mounted on the wing. Mark the bottom of each aileron leading edge 1 1/4 from the root end. Make sure you make a left and right aileron with the control horns on the bottom. 21. Use a 1/16 drill bit and drill the holes for the control horn mounting pins. Back up the balsa aileron with a wood block when drilling to avoid pushing out the back of the covering material and splitting the wood. 12
22. Press the control horn into the balsa all the way down so that the base of the control horn is flush against the aileron. Apply thin CA to the base of the control horn to ensure a secure joint. IMPORTANT: Be sure to make a LEFT and RIGHT aileron by mounting the control horns on the bottom of each aileron. 24. Install aileron hinges by first inserting a pin through the center of the hinge and then inserting each hinge into the pre-cut slots in the trailing edge of the wing as shown in the photo below. 23. Use wire cutters to cut off the control horn mounting pins flush with the top of the aileron. 25. Insert the hinges into the precut slots in the aileron. Ensure the aileron line up with the wing tip and that the hinges are straight. Then press the aileron against the pins. This ensures the hinges are centered between the wing and ailerons. Next remove the pins then press the aileron tight against the trailing edge of the wing. 13
26. Place a drop of thin CA on the top and bottom of each hinge. Be certain to allow for maximum control throw deflection prior to gluing. Do not use too much CA to avoid it running out on the wing or aileron or in the hinge gap and gluing the aileron to the wing. Attach the other aileron to the wing the same way. 28. Center control horn over the mark and in the center of the balsa elevator doubler and mark the location of the two control horn mounting pins. Ensure the control rod linkage holes in the top of the control horn line up with the leading edge of the elevator. Use a 1/16 drill bit and drill the holes for the control horn mounting pins. Back up the balsa elevator with a wood block when drilling to avoid pushing out the back of the covering material and splitting the wood. 27. Mark the top left side of the elevator ½ out from the fuse side. 29. Press the control horn into the balsa all the way down so that the base of the control horn is flush against the elevator. Apply thin CA to the base of the control horn to ensure a secure joint. 14
30. Use wire cutters to cut off the control horn mounting pins flush with the top of the elevator. 32. Place a drop of thin CA on the top and bottom of each hinge. Be certain to allow for maximum control throw deflection prior to gluing. Do not use too much CA to avoid it running out on the stab or elevator or in the hinge gap and gluing the elevator to the stab. 31. Install elevator hinges by first inserting a pin through the center of the hinges and then inserting each hinge into the pre cut slots in the trailing edge of the stab. Next insert the hinges into the precut slots in the elevator. Ensure the elevator tips line up with the stab tips and that the hinges are straight. Then press the elevator against the pins. This ensures the hinges are centered between the stab and elevator. Next remove the pins then press the elevator tight against the trailing edge of the stab. 33. Mark the rudder ½ up from the bottom on the left side. 15
34. Center control horn over the mark and in the center of the balsa rudder doubler and mark the location of the two control horn mounting pins. Ensure the control rod linkage holes in the top of the control horn line up with the leading edge of the aileron. 36. Press the control horn into the balsa all the way down so that the base of the control horn is flush against the rudder. Apply thin CA to the base of the control horn to ensure a secure joint. 35. Use a 1/16 drill bit and drill the holes for the control horn mounting pins. Back up the balsa rudder with a wood block when drilling to avoid pushing out the back of the covering material and splitting the wood. 37. Use wire cutters to cut off the control horn mounting pins flush with the side of the rudder. 16
use too much CA to avoid it running out on the fin or rudder or in the hinge gap and gluing the rudder to the fin. 38. Install rudder hinges by first inserting a pin through the center of the hinges and then inserting each hinge into the precut slots in the trailing edge of the fin. Next insert the hinges into the precut slots in the rudder. Ensure the rudder lines up with the bottom of the fuse, and does not scrape or touch the top of the fin. Ensure the hinges are straight, and then press the rudder against the pins. This ensures the hinges are centered between the fin and rudder. Next remove the pins then press the rudder tight against the trailing edge of the fin. Flight control assembly is now complete. 39. Place a drop of thin CA on the left and right of each hinge. Be certain to allow for maximum control throw deflection prior to gluing. Do not 17
SU-31 PROFILE ELECTRIC ARF WHEELS AND MOTOR ASSEMBLY 40. Locate the wheel parts pictured below. 42. Insert the longer landing gear wire into the upper hole in the landing gear mounting plate. Insert the shorter landing gear wire into the lower hole. 41. Note that the landing gear wires fit one on top of the other. 43. Install the two nylon wire ties through the predrilled holes and around both landing gear wires. Pull the wire ties snug. 18
44. Cut off excess wire tie strap with wire cutters flush with the wire tie head. 46. Assemble motor mount to the front of the motor. Now center the motor in the motor cutout in the nose of the fuse. Ensure the motor does not touch the fuse. Mark the position for the motor mount screw holes on the front of the fuse. 45. Install wheel spacer on the gear axles, followed by the wheel, and secured with a wheel collar. Tighten the wheel collar securely with a Phillips head screwdriver. Landing gear is now complete. 47. Use a 3/32 bit to drill the motor mount screw pilot holes into the hard wood blocks in the front of the fuse. Place a drop of thin CA into each hole to harden. 19
48. Install motor using two Phillips head self-tapping screws. Motor installation is now complete 20
SU-31 PROFILE ELECTRIC ARF SERVOS AND RADIO INSTALLATION 49. Insert the rudder and elevator servos with the output shafts facing forward into the servo wells in the fuse. The elevator servo is on top and the rudder servo is on the bottom. Mark the position of the servo mounting holes. 51. Insert the aileron servos into the servo wells with the output shafts facing the trailing edge of the wings. Mark the position of the servo mounting holes. 50. Use a 1/16 bit to drill the servo mounting holes. Use tape on the drill bit to make the hole only 3/8 deep. Do not drill all the way through the fuse if possible. Install servos with servo mounting screws. 52. Use a 1/16 bit to drill the servo mounting holes. Install servos with servo mounting screws. 21
53. Use a hobby knife to remove the covering from the opening on the right side of the fuse for the servo wires to go inside the fuse. 55. Attach a 6 servo lead extension to the rudder and elevator servo leads before fishing the leads through the fuse. Use a short piece of safety wire or a weighted string to fish the rudder and elevator servo leads from the tail. 54. Use a hobby knife to remove the covering from the opening on the right side of the fuse under the wing for the servo wires to exit the fuse. 56. Pull the rudder and elevator servo leads out through the exit hole under the wing. 22
57. Locate the 4 wire pushrods and 4 nylon R/C keepers shown in photo below. 59. Install the pushrod through the servo arm keeper and attach to the aileron control horn. Install the nylon keeper on the pushrod over the control horn. With the servo output arm 90º to the servo body and the aileron at 0º deflection, tighten the screw on the servo arm easy link. 58. Bend the end of each pushrod 90º with a 3/16 length. Install the nylon R/C keeper on each pushrod as shown in photo below. 60. Use wire cutters to cut excess pushrod wire off. Leave approximately 1/4 pushrod extending through the easy link for adjustments after final installation. Install both aileron pushrods the same way. 23
61. Using the same procedure, install the rudder push rod and attach to the rudder control horn and rudder servo output arm as shown in the photo below. 63. Attach a Y harness to the aileron servo leads. 62. Using the same procedure, install the elevator push rod and attach to the elevator control horn and elevator servo output arm as shown in the photo below. 64. Mount the battery in the battery compartment and secure with the pre-installed Velcro strap. 24
65. Mount the speed control on the left side of the fuse with double-sided tape. Attach speed control wires to motor according to speed control and motor instructions. Plug speed control radio lead into receiver throttle channel. 67. Run antenna wire along the bottom of fuse and secure with small pieces of clear tape. Wrap antenna wire around tail post and back forward toward nose. Secure as necessary with small pieces of clear tape. 66. Plug servo leads into the receiver according to radio instructions. Place receiver and excess servo wire into hole under wing. 68. Tuck and fold excess speed control wires under the battery Velcro strap. Leave the battery power plug out of the strap so power can be easily disconnected when finished flying. 25
PREFLIGHT PREPARATION Applying Decals 69. Cut the pre printed adhesive backed decals from the decal sheet and apply where desired. Clean the models surface with alcohol to allow a good bond to the surface. The decals may be applied using Windex or a solution of 1 drop of dish detergent to a cup of water sprayed on the model to assist in proper positioning. The water must be pressed out from under the decal after the decal is in position. Use a rubber squeegee or a credit card edge to press the water out Factory decal placement. Factory decal placement. Center of Gravity 70. The recommended CG is 2 5/8 to 3 from the leading edge of the wing measured along the outer wing rib at the wing tip. Do not skip this step! Factory decal placement. 26
Balance the SU-31 along the CG line with your fingers. Make sure the battery is installed and plane is ready to fly. Aileron throw measurement in inches. Elevator throw measurement 71. Start at the forward end of the CG range until you are comfortable with the flight characteristics of the aircraft. You may find this a bit nose heavy at first but that is fine to start with. After you are comfortable adjust the CG to suit your flying style in small steps, especially when shifting the CG toward the tail. Add small stick on weights to the nose or tail as necessary. 72. For 3D flying a more an aft balance point is better and for smooth pattern aerobatics a more forward CG is better. An aircraft that is too nose heavy does not fly well and is difficult to land. A tail heavy aircraft is uncontrollable and will likely crash. Control Throws Use a pen, ruler, and square to make rudder throw measurement. 73. The amount of control throw should be adjusted using mechanical means as much as possible and then electronically with the radio. The control throws are shown in inches of deflection measured at the widest point of the control surface for both low and high rates. 27
Control Throw Deflection Table Low Rate High Rate Aileron 3/4 up 1 ¼ up 3/4 down 1 ¼ down Rudder 1 left 1 3/4 left 1 right 1 3/4 right Elevator 3/4 up 1 ¼ up 3/4 down 1 ¼ down For 3D flying use the following throws: 3D Rate Aileron Rudder Elevator 2 up 2 down 2 ½ left 2 ½ right 2 ½ up 2 ½ down We recommend 15% Expo on low rates, 30% expo on high rates, and 40% expo on 3D rates as a starting point. You a can adjust from there to suit your own flying style. 28
Preflight Checks a. Center of Gravity: Check CG is set properly. b. Motor: The motor should run smoothly at all power settings with smooth transition from low to high RPM. Do not fly with an unreliable motor. Completely read motor instructions before flying. c. Flight Controls: Ensure all flight controls are free from binding and are centered. Check all hinges are tight and will not pull out. Control linkages must be rigid and tight and have no slop. Confirm proper direction of ailerons, rudder, and elevator. Experienced flyers have lost airplanes due to reversed ailerons. Right roll is right up, left down. Left roll is left up, right down. d. Batteries: Transmitter and receiver/motor batteries are fully charged before each flight. e. Fasteners: Check all motor screws, prop nuts, servo screws, control horns, wheel collars, and clevis keepers are tight and secure. f. Radio: Check trims set to neutral and controls centered. Check rate and condition switches set properly. Check the receiver antenna is fully extended. g. Range check: Do a range check with and without the motor running in accordance with the radio manufacturer instructions. If there is insufficient range or a large reduction with the motor running, do not fly until it is resolved! slop to avoid flutter at high speed. Large flight controls and large control throws can produce extreme and exciting maneuvers but can also generate tremendous stress on the airplane if full deflections are used at high speeds. When flying at high speed use caution using full control deflections to avoid overstressing the airplane. The SU-31 is capable of any aerobatic maneuver. After you gain some confidence and little experience flying the airplane you can cut loose and perform any maneuver you can think of. Here is a list of some of the more popular aerobatic and 3D maneuvers you can try: Loops and rolls Knife edge flight Stall turns Snap rolls 2, 4, and 8 point rolls Slow rolls Spins upright and inverted Flat Spins upright and inverted Harriers upright and inverted Water falls Torque Rolls Rolling circles The sky and your imagination are you only limits. FLY and ENJOY! AEROWORKS Flight Testing Plan the first flights with the CG in the forward part of the CG range. Use low rates or reduced throws until you are confident in the reactions to control inputs. After the first flight inspect the entire airplane for any loose fasteners or cracked joints. As you gain experience with the SU-31 move the CG back and increase control throws to the maximum for more extreme 3D aerobatics. Proper set-up is important for good performance. Control linkages must be rigid and tight and have no 29