Turnigy Tek Sumo

The Tek Sumo is a flying wing with an impressive range of flying characteristics.

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Specifications

• Released: Fall 2011
• Type: Powered medium sized flying wing
• Airframe: Rough EPP (Expanded Polypropylene) foam
• Wingspan 900 mm - 920 mm (measured)
• Wing area: 0.252 m^2 / 252 mm^2 / 390.6 in^2
• Length: 575 mm - 570 mm (measured)
  • Root chord: 290 mm (excl. elevons) - 345 mm (incl. elevons) [2]
  • Tip chord: 205 mm (excl. elevons) - 270 mm (incl. elevons)
  • Sweep: 315 mm (front to tip difference)
• Center of gravity: 200-212 mm (instructions), range 190-212 mm, from leading edge/tip - aim for 210 mm [3]
• Stock weight: 230 grams (wings, winglets, motor mount, servo mount, push rods, linkage, carbon fiber rods, front padding)
• Elevon travel range (radio programmable):
  • Elevator: +-15 mm
  • Aileron: +-10 mm
• Payload capacity: 100-250 grams (at least, CoG and power setup dependant)
• Reinforcement: Black carbon fiber spars, two 2x530 mm 1.9 gram wing spars, three 2x160 mm cross spars, two 3x320 mm elevon spars
• Recommended flying area: 250x250 meters [4]
• Product page: HobbyKing Tek Sumo

Manual

• Manual for Tek Sumo - Official manual

Stock kit

• 1x Tek Sumo 2 wing halves
  • 2x Pre-glued carbon fiber rods 2 mm on wings top and bottom
  • 2x Pre-glued carbon fiber rods 3 mm on elevons bottom
• 2x Winglets
• 1x Front EPP padding block
• 2x Push rods 1 x 200 mm
• 2x Glassfiber control arm 21 mm
• 2x Linkage stopper 1.5 x 6 mm
• 4x Equipment bay plastic bands 250 mm
• 3x Carbon fiber rods 2 x 160 mm
• 1x Plywood motor mount 38 x 38 mm backplate 23 x 23 mm pattern
• 2x Plywood servo mount 23 x 12 mm
• 1x Plywood velcro battery mount 71.5 x 25 mm
• 1x Fiberglass reinforced tape 15 mm
• 1x Instruction manual 4 pages

My setup

This is the current setup as of 2012-02-08:

• Motor: RCTimer BC2826-10 1400 Kv outrunner motor
  • Motor: RCTimer BC2826-6 2200 Kv outrunner motor
• Propeller: APC 7x4E propeller with 5.0 mm collet adaptor for 3.17 mm shaft
  • Propeller: APC 8x4E propeller with 5.0 mm collet adaptor for 3.17 mm shaft
  • Propeller: APC 6x4E propeller with 5.0 mm collet adaptor for 3.17 mm shaft
• ESC: RCTimer 30A Brushless Programmable ESC with T-type Deans and bullet connectors
• Servos: HexTronik HXT900 Blue 9 gram digital servos
• Receiver: Corona CR8D 2.4 GHz V2 DSSS 8 channel receiver
• Transmitter: Spektrum DX7 DSM 7 channel radio with Corona CT8Z 2.4 GHz V2 DSSS transmitter
• Battery: Moxie 2200 mAh 3SP1 11.1V Lithium-ion Polymer battery

Tips and tricks

• To glue the wing halves together and motor mount, use PU (Polyurethane) glue, e.g. Gorilla Glue, activate with water and keep pressed together using tape
• For attaching the winglets use hot glue in the main contact surfaces and silicone glue (GOOP) around the bead [5] [6]
• For better FPV signal conditions, replace the carbon fiber rods (1.9 gram) with 2 mm fiber glass rods (4.8 gram) on the wings and center spars, they're easy to undo, use thick super glue
• Use servo cable extensions to reach the servos from the equipment bay
• Reinforce the motor mount with super glue and kicker, paint it black for smoother appearance
• Calculate the motor and propeller size for the desired air speed, flight time and efficiency, use eCalc
• Make incisions to remove the floor in the equipment bays, make it even thinner and use PU glue+tape to re-attach the floor on the opposite side
• Put the equipments on the top side using the tip above to move the floors
• Relocate the servo holes to be perpendicular to the forward motion direction of the wing, position the servos horizontal (not vertical), double-sided adhesive pad+tape or hot glue, less drag [7]
• Use glass fiber reinforced tape to cover servo wire trails
• Cut a hallow 2 mm carbon fiber tube to fit over the push rod to minimize flexing
• On the tip of the elevons, cut off the corner to avoid the obstruction with the winglet
• Detach the elevons using a razor blade and reattach using strong 3M Mailing and Storage tape for optimal frictionless motion
• Reinforce the front tip of the wing by inserting two 3 mm x 110 mm carbon fiber rods into the foam from each side, pre-fit and use PU glue
• Scorpion, Hacker, Cobra are all reported to be very good motors if you want better quality [8]
• Fine tune the CoG (center of gravity) using the battery and motor as weights
• Pick a suitable motor+battery combination, simple rule: motor weight / 0.025 = battery capacity+-100 mAh, battery capcity * 0.025 = motor weight+-5g
• Center of gravity point is 190 to 212 mm from the front of the nose, depending on battery and total weight, aim for 210 mm [9]
• Program the travel range of the elevator to be 15 mm up and down, and the aileron to be 10 mm up and down from default position
• To maximum mechanical range (sensitivity) on the servo throws, use the outer most hole on the elevon control arm and the inner most on the servo arm
• To ease the sensitivity of the elevons, try 40% elevator expo and 80% aileron expo [10]
• Add a small sheet of coroplast and magnets to cover the equipment bay, use a 2 mm rod thought the flute hinge and PU or superglue for the magnet/metal piece

Motor alternatives

Scorpion, Hacker, Cobra offer quality motors, but the priority here is low cost.

• HK2824-1300 HobbyKing 2824 1300Kv Brushless Outrunner 52g [11]
• L2205-1350 Turnigy L2205-1350 1350Kv Brushless Motor 30g, pair with 1300 mAh [12]
• RCTimer BC2826-10 1400KV Outrunner Brushless Motor, 50g [13]
• D2822/14 Brushless Outrunner 1450kv 38g, pair with 1500 mAh [14] [15]
• Tower Pro 2409-12t 1600kv 63g, heavy [16] [17]
• RCTimer A2208-12 1800KV Outrunner Brushless Motor 38g, pair with 1800 mAh [18]
• RCTimer BC2826-6 2200KV Outrunner Brushless Motor 50g, pair with 2200 mAh [19] [20]
• Turnigy NTM Prop Drive Series 35-30A 1400kv Brushless Outrunner [21]
• Turnigy 2836 Brushless EDF Motor 3200kv 72g [22]

Setups

Optimal power train around 200-300W [23].

Guides

• 3DZone Center of Gravity guide
• Web-o-Calc propeller recommendation
• eCalc for propeller airplanes
• Propeller rule [24]:
  • Bigger prop - lower Kv motor, less amps, more thrust/climb
  • Smaller prop - higher Kv motor, more amps, less thrust/climb, more pitch speed

Common setups

• Docile/easy: Motor 1350 Kv D28xL19mm 40g, APC 7x4, 3S 1000mAh 83g [25]
• Cruising/easy: Motor 1450 Kv D28xL22mm 38g, APC 8x6, 3S 2200 mAh 170g [26]
• Cruising/FPV: Motor 1800 Kv D28xL22mm 38g, APC 7x4, 3S 1800 mAh 153g, 15-20 min flight [27]
• Cruising/FPV: Motor 1400 Kv D28xL26mm) 50g, APC 8x4, 3S 1500 mAh 138g, 15-20 min flight [28]
• Performance/long: Motor 1600 Kv D31xL31mm 63g, APC 7x6/8x4, 3S 2200 mAh 138g [29]
• Performance/speed: Motor 2200 Kv D28xL26mm 50g, APC 6x4, 3S 1500 mAh 138g, 10 min flight [30]
• Ultra/long: Motor 1400 Kv D35xL32mm 88g, APC 8x8, 2x 3S 2200 mAh 340g, 18-25 min flight [31]
• Ultra/fast: Motor 3200 Kv D28xL38m) 72g, APC 7x6, 3S 2200 mAh 170g [32]

Propellers

Common propeller sizes:

• 6x4, 7x3, 7x5, 7x6, 8x4, 8x8

Other equipment

• FeiYu Tech FY-21AP Gyro Stabilizing and autopilot [33]
• FeiYu Tech FY30A IMU Stabilizer [34]
• OpenPilot Stabilization [35] [36]

Flying weight

• 350 grams - setup 2208 1370 Kv, 20A ESC, 3S 1200 mAh, 6x5 [37]
• 489 grams - setup 2818 1350 Kv, 18A ESC, 3S 1800 mAh, 7x4 [38]

Build guides

• Flitetest Tek Sumo and Bonsai review
• bluegsxr6 Tek Sumo setup
• PaulT Tek Sumo build
• yarg Tek Sumo configuration suggestions
• octane81 Tek Sumo build [39]
• FPV Tek Sumo high speed mountain flyer [40]
• planex Tek Sumo setup
• FPV Sweden Tek Sumo build log
• XJet Tek Sumo RC plane of the week
• Rellik Demanon Tek Sumo setup
• beemerdon homemade balancing stand
• Joey6 Tek Sumo build and repair
• Tek Sumo and Zephyr compared

Tools

• Flying Wing CG calculator
• eCalc for propeller airplanes
• Web-o-Calc propeller recommendation

References

• HobbyKing Tek Sump EPP Wing
• RC Flight Test reviews
• Plane setup for success