the world‘s best designers united J35 Saab Draken By Michael Hammer 3DLabGANG project by Michael Hammer
the world‘s best designers united The real Saab Draken The Saab Draken was developed by Saab in 1955 and was the first fighter aircraft designed with double delta wings. The unconventional wing design also had the side effect of making it the first known aircraft to be capable of and perform the Cobra maneuver. The Draken functioned as an effective supersonic fighter aircraft of the Cold War period.
the world‘s best designers united The J 35 Saab Draken semi scale model The 3D printed Saab Draken is designed to look and fly like the full size Draken. The lines and proportions of the model match the real jet with its elegant double delta wing and leading edge air intakes. The optimized edf duct ensures great performance without the use of cheater holes or non scale sized air intakes.
the world‘s best designers united Bill of Materials 1mm pianowire Spring from ball point pen Cyano hinge sheet Cyano glue and accelerator spray, medium or thin 2 x HTX900 servoes or similar 9g servos EDF: FMS 50mm 4S edition available at Aliexpress.com Receiver: 4-6 ch ESC: 40A Battery: 4S2200mAh 25C or higher 3D Printer Requirements Recommended Prusa MK3S : 250 x 210 x 210 mm, minimum diagonal for wing chord is 297 mm Nozzle: 0,4mm Filament: PLA or PolyAir 1.
the world‘s best designers united 3DLabGANG project by Michael Hammer
the world‘s best designers united Important All printed parts should be cleaned up using a sharp knife or sandpaper. It is especially important to prepare the fuselage sections well so they will slide easily into the neighboring part. Use a piece of sandpaper to bevel the edges of the parts. Outer wall should be beveled on the inside, and the EDF duct should be beveled on the outside.
the world‘s best designers united Fuselage Assembly The fuselage parts are best assembled by applying thin cyano glue to the outside seam. It is not necessary to glue the edf thrust tube. Make sure the parts are perfectly aligned and start with one of the “corners”. Use your fingers to press the parts firmly together and apply a small amount of thin cyano and spray with Accelerator. Pick the next “Corner” and repeat the procedure. Work your way all around the the fuselage part.
the world‘s best designers united Continue with fuselage_07. Route the servo extension wires through Fuselage_07 and fit in together with Fuselage_09 and 08. Take your time getting the parts lined up perfectly before adding any glue. It is now time to add the EDF thrust tube. Cut a hole in the tube with a soldering iron, hot knife or Dremel at the marked location for the EDF motor wires.
the world‘s best designers united Fuselage_04 and 03 are the most difficult parts to assemble because of the bifurcated EDF ducts. Make sure to bevel the outside edges of the ducts with sandpaper and the inside edges of the receiving opening. Take your time and repeat the sanding until both parts slip together nicely. If you don´ t succeed at first then put it aside for a while and jump ahead and assemble the elevons or the vertical stabilizer. Then come back and try again.
the world‘s best designers united Hatch Assembly You will need a spring from a ball point pen or similar. The latch has a recess that fits the characteristic dragon fin shaped dorsal antenna. The side with the recess should point upwards. Make sure the spring can be pushed onto the latch. Insert the latch and spring into the slot in the hatch. Press the latch all the way in and glue the dorsal antenna into the recess on the latch.
the world‘s best designers united Vertical Stabilizer assembly The vertical stabilizer consists of 4 parts and a joiner. Test fit the joiner into the slot of Stab_01 and make sure that only half of the joiner protrudes from Stab_01. Slide Stab_02 onto the joiner and check that Stab_01 and 02 fit together nicely. Remove Stab_02 and if necessary reposition the joiner in its correct position. Add thin cyano to the joiner and spray with accelerator. Glue Stab_02 onto Stab_01 using medium thickness cyano.
the world‘s best designers united Test fit the vertical stabilizer onto the fuselage. Make sure the stabilizer is properly seated and perpendicular to the fuselage (pointing straight up). When satisfied with the fit, add thin cyano to the seam all the way around the vertical stabilizer.
the world‘s best designers united Wing Assembly The outer wings consist of 4 parts and 6 joiners. Test fit the joiners into the slots of Wing_Left_01 and Wing_Left_02. Make sure that only half of the joiners protrude. If necessary reposition the joiners in their correct positions. Add thin cyano to the joiners and spray with accelerator. Now Slide Wing_Left_02 into position with the fuselage. If the fit is not acceptable, remove Wing_Left_02 and blocksand the mounting surface of the fuselage.
the world‘s best designers united Elevons assembly The full size Saab Draken has two elevons on each wing that move in unison. The Draken model replicates this setup. Line up the Elevon_01 and 02 with each other and glue with medium cyano. Drill a 1mm hole in the control horn at the position of the 3D printed hole. Cut four hinges from a Cyano hinge sheet with the dimensions of 15x25mm and one 15x20mm.
the world‘s best designers united Mount the HXT900 or similar servos in the servo mounts with the supplied screws as shown in the photos. Make sure the servoes are in their neutral position and the servo arm is pointing straight up. Connect the control horn on the elevons to the servo control arm with a 1mm piano wire. Use your preferred method of connecting the servo, piano wire and control horn. Personally I prefer connection with a piano wire with a z-bend in both ends.
the world‘s best designers united If you plan to launch the Saab Draken with a catapult which I highly recommend then glue the catapult hook into the prepared hole in the models belly. The real Saab Draken had some distinctive afterburner inlets on both sides of the rear fuselage. Marks on Fuselage_10 and Fuselage_11 show the correct location of the inlets. Check the fit of the afterburner inlets and glue with cyano.
the world‘s best designers united EDF Assembly Place the two EDF_Mount around the FMS 50mm EDF as shown in the photo. Use small screws to secure the EDF between the mounts. Do not tighten too much. The EDF fan should be able to turn freely without rubbing against the shroud. Make sure to cut of the tip of the screws if they protrude from the mount. Instead of screws you can also use medium cyano glue.
the world‘s best designers united Battery positioning The Saab Draken has an adjustable battery tray system that makes adjusting the Center of Gravity very easy. Secure the battery to Battery_Tray with velcro (strong adhesive) or use hot glue. Slide the battery tray and battery into the slot in Fuselage_07 and feel how the battery tray can be locked in three different position.
the world‘s best designers united Control Throw Adjustment Use the control gauge to adjust the elevon control throws. The marks in the gauge should line up with the upper side of the elevon. The marks indicate the amount of throw needed for max elevator and max elevator + max aileron in both directions. Use your transmitter to adjust the throws. You will also need to program your radio for the elevon function.
the world‘s best designers united Center of Gravity Before first flight make sure the model will balance at the Center of Gravity, CG which is indicated underneath the wings as two raised dots. If you lift the ready to fly model it should balance at the CG marks. If the model does not balance at the CG marks move the battery forward or backwards until the model balances at the CG mark. First flight Always remember: It is the airflow across the wings that creates lift. Keep the airspeed up at all times.
the world‘s best designers united Landings should be performed on a grass strip with short cut grass. Bring the model in low over the end of the grass strip but with enough speed to avoid any stall situation. At very low height over the grass keep dialing in elevator until the model settles on the grass at almost stall speed. Be careful not to add too much up elevator when landing.
