FPV ES Drifter Ultralight - 950mm

Details

 

About

This is ES DRIFTER manufactured by EASY SKY. Model belong to the scale flight category the "Ultralight" which based on existing real ultralight planes, should not be confused by a Glider category since it doesn't have such flight characteristic of a glider either.  Marketed towards basic and intermediate R/C pilot which can easily bought from online stores. Wings and cockpit are made of light EPO foam,plastic skeletal main frame, while the tail boom and wing support cabane are made from carbon fiber.  Stock airframe are extremely lightweight and suited to any R/c flyer who just graduated from basic flying or getting a second plane. 

During its first introduction into the R/C community the trend didn't pickup well because FPV community was too reluctant to use it as FPV platform due to its size and very sensitive to wind flying characteristic.  So i stepped out, took my first bite to convert it into scale FPV platform, 2x month after continuous flight success i manage to convince the FPV community that this is most ultimate scale Drifter Ultralight for FPV into epic sky adventure.

 

 dr 5

 

Model specification & setup

Airframe type: Ultralight
Branding/Manufacturer: Easy Sky
Model name variant: DRIFTER
Material build: EPO 60% + Plastic 20% + Carbon fibre 20%
Wingspan: 950mm
Length: 850mm
Stock airframe weight: 460 gram
Full FPV flying weight: 615 gram
Aileron: 1x 5g servo
Elevator: 1x 5g servo
Rudder: 1x 5g servo
ESC: 20A
Motor: Stock 2300KV (2s) when using 3s lipo throttle control max limit at 85%
External BEC: 5A/5V
Propeller: Stock 2 blade 7x3.5"
Radio receiver: Frsky telemetry 8ch
Radio receiver antenna: diversified DIY di-pole antenna
Battery: 1x 2200mah 2s~3s 25c
Center Gravity: 1/3 from the front leading edge of the wing. Nose tilt down 5% from horizontal.

 

 

My DIY FPV specification

Camera: 808 #16 V2 HD with live video out
Secondary camera: None
Camera pan/tilt mechanism: 9g HXT900 (180 deg mods)
OSD: Arkbird OSD/RTH/GPS V1/3DR-APM
Flight Control board (Drifter 1): 3D Robotics/APM
Flight Control board (Drifter 2): Arkbird OSD /RTH/GPS V1
Flight Control board (Drifter 3): 3D Robotics/APM
Video transmitter: Boscam 5.8ghz
Video antenna: DIY tuned Clover Leaf
Battery: Shared with main.

 

Building

Even before i had my hands on this, by looking at the catalogue i knew from the start that this platform indeed is going to be the scale FPV king.  It wasn't that hard to install everything in place, the whole fuselage are very open and accessible for direct hardware placement.  Just need to remove the back seat to accommodate extra space for modules such as AP flight board like ARKBIRD, FEIYU, ARDUPILOT or STORM OSD.  The placement for main lipo battery are located frontal nose under the cockpit dashboard optimal fits 2200mah 3s 25c with minor foam scrapping,  you'll get a perfect CG from there at 1/3 from the front leading edge of the main wing.   Under the fuselage you can put your video transmitter upside down for better L.O.S antenna transmission, the landing gear holds great to provide ground clearance for clover leaf or short omni antenna.  The RF separation between my RX module with diversified di-pole antenna, VTX module with CL antenna, ferrite less UBEC and ESC is well distanced among each other allow clean and clear RF frequency propagation to my FPV Ground Station with no L.O.S obstruction.   On the first day of FPV  it maiden without a hitch, had a first beautiful flight.  2 months later a second Drifter Ultralight with exactly same hardware build was born.  I have twins and i love them dearly.

FPV building level difficulty/rating: Hard/Advance (2/10)
FPV equipment setup grade: Advanced
Building hours required: 48 hours
Skill required: Soldering/Foam cutting.
Critical issues during installation: Keeping the weight to most minimal.
Required additional mods/must do improvement: Beef up the motor mounting/solid reinforcement + re-glue all control hinges.



dr 10 

 

FPV flight characteristic and performance

Slow, relaxing, maneuverable, agile, responsive and hover-ability are best way to describe its flying characteristic. It sounds  easy to fly if the airframe was build/setup right from the start especially the CG and the control trimming are correctly setup.  Slightly 15% heavy on the nose is very recommended. 70% of the owner got the setup wrong on their first ownership short lived their flight permanently because Drifter Ultralight is sensitive to improperly setup/build. When FPV throttle control and rudder control is the key to successful flying.  When i fly as FPV in a Drifter i don't feel the "heaviness" and "lagness" of a glider, it feels more freedom and floatiness in 360 degree control.  Glider like AXN and SKY SURFER/BIXLER feels very sluggish, heavy and it felt like it was swimming inside murky mud, however the Drifter Ultralight coasts like unsinkable Swan. I don't have to worry about countering the aileron rolls because the airframe is naturally have positive CG "pendulum effect" due to high wings and distance to base airframe CG.   Both VLOS and FPV takeoff and landing are fairly easy to do.  The day i flew the Drifter Ultralight is the last day i every going to touch my Gliders (AXN & SKY SURFER), no turning back Drifter rocks.


Minimum level of VLOS flight experience required/flight-hours: Advance(580 hour)
Minimum level of basic FPV flight experience required/flight-hours: Intermediate (325 hour)

Nature of platform handling experience/skill required: Glider, scale and acrobatic flight
Self leveling capability in thumbs-off stick situation: Yes
Take-off & landing difficulty: Easy
Hand launch: Yes
Max speed: 55~km/h
Min speed before stall: 5~15km/h
FPV flight/radius: 4~12km max (given above FPV spec/setup)
Max altitude: -
Bail-out/fail safe recovery altitude limit: 10~30m
FPV safe distance range for testing: 700~900m (Open field)
High angle of attack (AOA) tolerance limit before stall: Not applicable.
Ground "STOL" (Short Take Off and Landing) capability/thrust%: Takeoff 20m (60%)/ Landing 10m (20%)
Altitude climbing power/thrust%/AOA angle: 4 sec/per-meter at 45% thrust/20 degree
360 degree turning radius clearance/holding pattern: 15m
360 barrel roll/loop acro flight: Yes (Aerobatic)
Control expo - aileron: 45% (low to high)
Control expo - elevator: 45% (low to high)
Control expo - rudder: 45% (low to high)
Control end point - aileron: 80% (low to high)
Control end point - elevator: 100% (low to high)
Control end point - rudder: 100% (low to high)
Flight time: 35~55 min
Ground spotter visibility (LOS): 400~600m5

 

 

Safety issue

Flies like a gentle swan and drop like a swaying leaves.  This little floater posses little threat to any ground object.  However care to be taken during its first built because factory assembly isn't 100% durable and tight build, factory dry glue may come off from the control rods and soldered wires are "cold soldered" and may fracture at their junction connector especially the motor micro bullet connector.  Stock ESC on 3s will last less than 3~5 flights.  Before maiden proceed to fix the mentioned issues.

 

 

Pros and Cons

Here are list of pros and cons about this platform. Some of this are needed to take seriously if you are going deep into long term FPV ambition

Pros:

  1. Extremely lightweight airframe.
  2. Good altitude climber with less thrust power usage >>30~45%<< thrust.
  3. Open fuselage for ease installation, maintenance and cooling.
  4. Low wind resistance airframe fuselage provide better flight endurance and upright stability (pendulum effect)
  5. Low inertial ground impact risk due to extremely lightweight airframe.
  6. Best low speed cruising, relaxing control and 360 degree maneuverability.
  7. Small, portable and easy to dismantle the wings for packaging/travelling portability.

Cons:

  1. Full throttle at beyond 75% and "force throttle" altitude climbing  is useless and wasted too much power per-distance because the airframe speed efficiency decrease exponentially downwards.  Best for slow relaxing flight and linear throttle only because its a slow flyer.
  2. Stock motor and stock ESC will burn if throttle beyond 85% on 3S lipo setup, immediate ESC replacement before first flight is compulsory.
  3. Factory glue on control rods, wing support and motor mounting are weak, needs extra fix and reinforcement work.
  4. CG sensitive platform required accurate hardware placement on the fuselage, anything exceed 750 gram of flight total weight will not offer a good performance and FPV flight handling.

 dr 4

 

Current status & flight history

My Drifter is still going strong still fun to fly around in any weather condition. Its still the best platform to have for multi-purposes role  such as cross country adventure, path/trail finder, aerial video/photography, ground mapping, surveying, does excellent Search and Rescue platform for close to ground proximity flight.  Not only it flies great but also great for travelling companion because its the platform can be easily disassemble and store inside a small compact box.  The open skeletal airframe also is subject to unlimited possibilities of creative modification and future add-on/payload.

 

Lifespan operation: 3 years (updated on 19 June 2015 for Drifter #1 and #2)
Start operation: late 2012 (Drifter #1 and #2)
Total of active unit: 2x FPV Drifter Ultralight (1x UAV Drifter Ultralight #3 V5)
Maintenance priority check: Motor mounting
Constant critical issue: None
Maintenance cost per-lifespan: None
Flight hours accumulated per-lifespan on DRIFTER #1 (FPV): 824 hours (updated on 19 June 2015)
Flight hours accumulated per-lifespan on DRIFTER #2 (FPV/UAV): 831 hours (updated on 19 June 2015)
Best L.O.S distance record for Drifter #1 : 15km  (updated on 19 June 2015)
Est. distance covered per-lifespan (FPV - Drifter#1): 18,950km (Odo) (updated on 19 June 2015)
Est. distance covered per-lifespan (FPV/UAV - Drifter#2): 17,211km (Odo) (updated on 19 June 2015)
Best height record: -
Best flight time record per-session: 55min (2200mah 3s 35C for Drifter #1 and #2)
Best low hovering speed record: 5km/h
Best record  for zero thrust landing distance/power failure glide recovery distance: 1.5km/300m alti. via tail wind.
Activity status: Still active for all unit.

 

 

Latest Log:

(updated: 19/5/2016)

  • New setup article on UAV Drifter Unit #3 V5 have been publish, which blog about Autonomous flight setup using APM (Ardupilot/Arduplane) system.

(updated: 7/11/2015)

  • Drifter Unit #3 highly active in various autonomous mission and mapping activity, most operation are operating at average 100m altitude and made great long range autonomous flight while scanning/mapping throughout the terrains. All communication and links to Drifter unit #3 is via telemetry radio connected to android phone and windows notebook for mission planning and real time monitoring.  Drifter Unit #1 also communicated in similar setup too.

(updated: 30/9/2015)

  • Drifter Unit #1 resurrected with new replacement parts, flight controller no longer using ARKBIRD but instead uses open source APM MINI PRO similar to DRIFTER Unit #3 setup with reliable and efficient 18A ESC and new high capacity BEC.  Expected to continue air services as usual.

(updated: 6/9/2015)

  • Drifter Unit #1 crashed into the sea after video signal interrupted/cut out by external FPV model on the same area that uses illegal/non-FCC compliant over wattage video transmission (600mw) from newly setup ALIGN M4*0L quadcopter nearby operated by new user who seem to ignore the R/C flying rule book about respecting local video FPV frequency.  Drifter Unit #1 retrieved thanks to local fisher man. Main wing tore apart.  808 #16 HD board and RUNCAM HS severed damaged,  FC baro toasted, Elevtor damaged and electronics health status still unknown.

(updated: 5/8/2015)

  • Acquired 3rd unit of Drifter into the fleet (Drifter #3),  will be powered on 3DRobotics APM.  This plane built specially super lightweight build for low altitude flight, high endurance and power efficient. Planned for off-shore flight, aerial photography and mission planned via Android powered Ground Station.  One of most technological advance autonomous flight system among fleet of Drifters.

(updated: 17/1/2015)

  • 2nd Drifter (Unit 2) receive pan-tilt upgrade for more improve "Search and Rescue" style cam 3d printed kit: The "XL-RCP 14.0 HAWX EYE" for Drifter Ultralight and compatible. Nose mounted lighweight nano pan-tilt camera for unobstructed full clear FPV view. Click here to view the 3d printing kit and downloads.

(updated: 22/1/2015)

(updated: 20/3/2015)

  • Drifter #2 (Unit 2) now serve as "flight mule" to carry various HD camera devices from various vendor with payload up to max 93gram of camera weight for product test and review on consumer HD camera devices. 

 

 

 

Summary

The ES Drifter Ultralight is the most relaxing FPV platform to fly, sit down and enjoy the scenery around the cockpit.  However highly recommended to have basic r/c flight at least on a glider before flying it.  A good CG will determine its flying characteristic, a slightly nose heavy is even better.  Unlike the tough bash-able intermediate level plane the Drifter is a brittle platform, care taken not to push this brittle air frame to its limit.  The Drifter is ideally a good platform to tour around local places at low altitude and slow paced flying, it even performed best if weight is highly reduced.

 

 

Videos/Medias
MediasHere are some of my video and gallery related to the above topics:

 

 


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Shopping list

Here i've listed some raw material, hardware and stuff where you can start building your own FPV platform.  The list contain the above hardware and also include some compatible ones which you can pickup what suits best for your need and your budget.  So come dig around and start your tech flying ambition:

  1. Platform/Airframe:
  2. Radio set/combo:
  3. Motor/ESC/BEC:
  4. Servo:
  5. Camera/HD/DVR:
  6. Flight controller/AP System/OSD:
  7. Video transmitter/combo:
  8. Battery:

 

 

 

Building threads/Referral

If you don't know where to begin with i recommend you to start reading some guides, wikis and building tips from popular on-line resources as listed below.  You might find me wondering around some popular R/C and FPV forum below.

 

 

dr 11

 

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