TBS Discovery

The Team BlackSheep (TBS) Discovery is a purpose made FPV platform based on the DJI Flame Wheel F450 frame base.

It has a asymmetric structure to offer a propeller free view, incorporates traces on the central core plates to minimize wiring, has space for both a flight camera and HD recording camera (GoPro) in the front and a protective cage for a high capacity LiPo battery in the back.

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Specifications

• Released:
  • DJI Flame Wheel: November 2011
  • TBS Discovery: June 2012
• Type: Spider quadrotor
• Airframe: Caron fiber reinforced
• Diameter: 450 mm - Flame Wheel, Discovery is a bit wider
• Height: xx mm
• Weight: 460 grams [1]
• Takeoff weight: 800 grams to 1600 grams
• Battery: 3S-4S LiPo
• Motor: 22x12 mm or 22x15 mm
• Propellers: 10x4.5 in (3S batt) or 8x4.5 in (4S batt)
• ESC: 4x 20-30A switched
• Forward speed: ~60 km/h / ~40 miles/h
• Behaviors like: T-Rex 450 without 3D capability [2]
• Recommended flying area: 25x25 meters
• Clone models: HJ450, RM450 and Q450 [3]
• Product pages:
  • DJI Hobby - Flame Wheel kits and NAZA flight control
  • Team BlackSheep - TBS Discovery FPV specific base

Frame kit

The quad is build using separate base plates and frame arms. In other words, it is a purpose built kit using the DJI Flame Wheel arms for structural support and TBS Discovery plates for the central core and electronics installation.

• 1x DJI F450 Motor+Propellers+ESC+NAZA kit - from Flying-Hobby
• Alternatively:
  • 2x DJI F450 Flame Wheel black arm - from Flying-Hobby
  • 2x DJI F450 Flame Wheel white arm - from Flying-Hobby
• 1x TBS Discovery top and bottom plate including screws and damping tape - from TBS
• 1x TBS CORE video power distribution and OSD system - from TBS
• 1x TBS 100A current sensor - from TBS
• 1x TBS RF Tin Shield for TBS CORE - from TBS

Manual

• TBS CORE manual - power distribution for the video system
• DJI F450 Flame Wheel user manual v1.6 - basic setup instructions for the Flame Wheel
• DJI NAZA Assistant user manual v1.4 - configure the flight controller
• DJI NAZA Assistant user manual v2.1 - configure the flight controller
• WKM Detailed Descriptions on Autopilot parameter setting
• TBS Discovery graphic

My setup

• F450 Flame Wheel setup - basic setup of the DJI F450 Flame Wheel
• TBS Discovery setup - list of my settings and configurations for the TBS Discovery

Base setup

This is the basis for the quad and makes for a perfect platform to start testing equipment.

• Motor: DJI 2212 920KV 144W brushless motor
• ESC (4x): DJI OPTO 30A no-BEC brushless speed controller
• Propellers: Graupner E-Prop 10x5 inch propeller set [4]
  • Alternately: Gaui G-222800 10-inch propeller set (for GAUI 500X quad) [5]
• Flight Controller: DJI NAZA no-GPS flight controller
• Transmitter: Spektrum DX7 radio with FrSky DHT 2.4 GHz 60mW transmitter
• Receiver: FrSky D6FR 2.4 GHz 6-channel two-way receiver
• Battery: Turnigy nano-tech 3300mah 35~70C 4SP1 14.8V Lithium-ion Polymer xx grams battery

Upgraded setup

• Motor: RCTimer A2830-14 750KV outrunner motor [6]
• ESC (4x): Hobby King F-30A Brushless Programmable ESC with bare leads - reprogrammed with RapidESC firmware
  • Alternately: RCTimer 30A Brushless Programmable ESC with bare leads, internal oscillator (not optimal) - reprogrammed with RapidESC firmware
• Transmitter: ImmersionRC EzUHF 433 MHz transmitter - long range
• Receiver: ImmersionRC EzUHF 8-channel 433 MHz diversity receiver with Sander Style UHF antennas - long range
  • Alternatively: FrSky D4R-II 4-channel 2.4Ghz 8ch-CPPM RSSI two-way receiver - light and small
• Flight Controller: OpenPilot CopterControl flight control - limited availability

Motor combinations

This is a list of verified setup from people who has built their Diso.

• RCTimer A2830-14 750KV 185W outrunner motor
  • Suggested setup: Gaui 500X 10-inch set, Hobby King F-30A 30A ESC Simon flashed, Nano-tech 4S 2200mAh, OpenPilot CC [7] [8]
• NTM 28-30A 750KV 140W prop drive series motor
  • Suggested setup: Gaui 500X 10-inch set, Turnigy Plush 25A ESC Simon flashed, Nano-tech 4S 1800mAh [9] [10]
  • Suggested setup: Graupner E-Prop 10x5 set, Nano-tech 4S 3300mAh, 1420g with GoPro, 14 min flight time [11]
• NTM 28-26A 1200KV 250W prop drive series motor
  • Suggested setup: APC 8x3.8 propellers, Turnigy Plush 30A ESC, Nano-tech 4S 3300mAh, OpenPilot CC [12]
  • Suggested setup: APC 10x4.5 propellers, Hobby King F-30A 30A ESC Simon flashed [13]
  • Suggested setup: APC 10x4.75 propellers, Hobby King F-30A 30A ESC Simon flashed, 4S battery [14]
• DJI 2212 920KV 144W brushless motor [15]
  • Suggested setup: Gaui 8-inch set, DJI OPTO 30A ESC [16]
  • Suggested setup: Graupner E-Prop 10x5 set, DJI NAZA controller [17]
• Suppo 2810/12 1000KV 225W brushless motor
  • Suggested setup: Graupner E-Prop 10x5 set, DJI OPTO 30A ESCs, DJI NAZA controller [18]
• Suppo 2814/8 1000KV 380W brushless motor
  • Suggested setup: Graupner E-Prop 9x5 set, DJI OPTO 30A ESCs, 4S 3000mAh+1800mAh, DJI NAZA controller [19]
• Tiger MT-4006-13 740KV motor - no punch, vibration free
  • Suggested setup: 11-inch propellers, 4S battery, DJI NAZA controller [20] [21] [22]
• Graupner Compact 300 740KV 9.6V - expensive
  • Suggested setup: Graupner ESC 18-SC, DJI NAZA controller, Nano-tech 4S 3300mAh [23]

Potential other candidates:

• TorxPower MC2216 Pro 900KV 210W brushless motor [24]
• NTM 28-26 1350KV 310W prop drive series motor [25]
• NX-4008 620KV Brushless quadcopter motor [26] [27]
• FM-4008 620KV Brushless quadcopter motor [28]
• Avroto M2814-11S Short Shaft 770KV 350W Brushless motor [29]
• Tiger Motors MT-2216-10 900KV 210W brushless motor [30]

Accessories

• USBasp AVR Programming Device for Atmel based ESC controllers - Hobby King
• 3M Double-sided tape pack - Hobby King

Tips and tricks

• To get rid of vibrationse/jello, use only good quality propellers, e.g. Graupner and APC [31] [32]
• For longer flight times, use low Kv motors and large propellers but watch the power usage
• To avoid propellers in the GoPro view, use Wide setting for 8-inch propellers and Medium for 10-inch propellers
• A 25A ESC is more than enough for this frame, max. 60A full throttle for all four controllers equals 15A per ESC, 10A margin [33]
• To a clean ESC install, solder the 3.5 mm socket motor connectors directly on the controller board [34]
• The standard DJI motor and propellers use a 8 mm shaft/bell, APC props are 6 mm and has to be adjusted, Graupner is 8 mm [35]
• Program the ESCs to be set up with Break off, Battery type NiMh (to turn off LiPo voltage cut-off), Cut-off type: soft cut, Cut-off voltage low, Aircraft type airplane, Start mode normal, Timing/response mode high (400 Hz), Governor off and everything else off [36] [37]
• Calibrate the throttle range for each ESC individually by setting the throttle stick high on power on and then low until a confirmation beep is heard
• Consider upgrading the ESC firmware to SimonK version get the full refresh rate needed for multirotors, RapidESC database shows all capable controllers
• Propeller thrust is only the amount a motor can carry/load, not at which speed, so therefore thrust determines the acceleration, kV determines the speed range [38]
• Only connect one BEC 5V power supply from a single ESC, disconnect the red power lead from the other three ESCs [39]
• On the flight controller, set Kp (instantaneously proportional error correction) to a high value to make the quad responsive and decrease 20% when it oscillates/nags, set Ki (integral/sum errors over time) to a high value to make it steady in windy, improper center of gravity, fast forward or long dives/turns, situations where the quad is off level for a fairly long period, decrease 20% when long slow oscillations occur [40]
• Since the front two arms are asymmetrical, increase pitch Kp and Ki with 1/3 of the value for roll (for OpenPilot) [41]
• On NAZA, set up signal loss fail-safe so that throttle is above 10% and that flight mode is put to 70% or the position NAZA will go into fail-safe mode, one less fall from the sky to worry about [42]
• In a dive the back-end of the Discovery might not fall as quick as the front, a way to counter this might be to set Ki for pitch (OpenPilot) to higher value to correct for the lack of power to the front motors [43]
• The results on eCalc might show "over power", but since this is a multirotor the load is shared and only in bust/acceleration moments will the motors be taxed [44]
• If the motors stall, try to increase the battery voltage, e.g. go from 3S to 4S batteries to increase/up the torque of the motors [45]
• Balance the motor by attaching a zip-tie spinning the motor up, stop and move the zip-tie and try again, the point of least vibration is the point where centre of rotation and mass is close to zero [46]
• Change the throttle curve, either in OpenPilot (preferably) or on the radio, to be flat in the middle to reduce the change in throttle versus the stick movement, this should smooth your throttle response and allow for easy altitude adjustment - see pic [47]
• Reduce the top throttle point to 90% to make sure the flight controller can take over control when throttle stick is at full
• In DJI NAZA Assistant setup, start off using basic rate gain 150/155/120/100 and for attitude gain 125/125, then adjust as needed [48] [49]
• To make the movement of the sticks less sensitive around the center, add 40% expo for elevator and aileron, 20% for rudder in the radio programming [50]
• Center of Gravity (CG, CoG) is for balance, distributing the weight equally over each motor, bind two pieces of strings to create an X, this is the CG spot [51] [52]
• The flight controller does not need to be over the CG spot, on the TBS Discovery it should be mounted in the center of the two sets of four holes on the bottom plate [53] [54]
• Mount a GPS unit on the CG spot, or, anywhere on the frame and compensate the offset from CG in the software setup (NAZA Assistant) [55] [56]
• To get a smooth ride, lower the rates, i.e. the range of travel for aileron, elevator, rudder and throttle, so that a lot of stick input results in little actual quad movement, use a switch to change between two sets of rates (dual rates, launch and smooth ride) [57]

Build logs

For details on building and setting up the Discovery, take a look at the pages below for an idea.

• juz' OpenPilot build log
• Enthlapy's OpenPilot build log
• meme's build log
• Rensen's DJI Build Log
• Traveller's Disco build adventure
• kloner's TBS Discovery build log
• olivier30900's NAZA GPS build log
• WiseDuck's NAZA build log
• isotop's NAZA low cost build log
• acuralegendz's NAZA build log

Also follow TBS Discovery quadcopter thread on FPVLab.

Tools

•  eCalc - find the optimal propeller+motor combination
• NAZA gains database - get an idea of the gain to aim for

Shops

• teamblack-sheep.com - Home of TBS Zephyr I & II, Discovery and CORE, AU
• rctimer.com - Lots of motors, ESCs and clone Flame wheel, CN
• flying-hobby.com - Good selection of DJI items and great prices, HK
• goodluckbuy.com - DJI items and a lot of other accessories, HK
• uavproducts.com - Source for DJI kits and frames, US
• hobbyking.com - Motors, ESCs, batteries and a lot more, HK
• hobby-wing.com - DJI parts and clones, HK
• globe-flight.de - Multicopter items, FPV equipment, propellers, DE
• servocity.com - Pan and tilt systems
• addictiverc.com - Source of Graupner propellers, US
• elecricwingman.com - Another source of Graupner propellers, good prices, UK
• gothelirc.com - APC, Gaui, Graupner propellers, US

Video

This is the official Team BlackSheep video of the final production frame.

References

• TBS DISCOVERY - New quadrocopter frame