AOS LR5
The latest version of this frame is the AOS LR5 EVO. It soft mounts the FPV Camera, supports ND filters with DJI O3 and fits 14-20mm FPV cams (14mm uses a 3D printed mount, STL provided below).
The AOS LR5 is an ultralight 5 inch frame designed for long range and immersive freestyle. Explore like never before with a long range frame that's easy to tune and loves to freestyle.
5" Ultralight long range provides the opportunity to explore further, using the same batteries as you would use for your 5" mini quad or 6S 18650 Li-Ion based packs for the longest flight durations (15+ minutes).
Other long range frames are difficult to tune, lacking in durability, and uninspiring to fly freestyle. The LR5 addresses these limitations to deliver a frame that is equally at home exploring or ripping freestyle in a park.
The 5 mm thick arms provide exception vibration and resonance performance, making the design easy to tune, smooth and responsive in the air as well as providing the durability to shrug off light crashes.
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No props in view
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Designed for 5" biblade props
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5 mm Arms
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1.5 mm Top Plate, Bottom Plate and Sandwich Plates
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One 25.5 or 20 mm mounting up front and one 30.5, 25.5, or 20 mm mounting in the rear (2 stack configuration)
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One central 25.5 or 20 mm stack (1 stack configuration)
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Supports HDZero 1W VTX or DJI Air Unit in the rear
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Fits 19 mm and 20 mm cameras
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Recommended components:
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2004 motors
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30A or higher toothpick AIO
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Caddx Vista/Air Unit + DJI Camera
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4S ~800mAh or 6S ~500mAh w/ XT30
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~68g with steel hardware
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Standoffs, carbon and hardware included
ULTRALIGHT
LONG RANGE
Designing for long flights
Long range drones use larger propellers for their weight to improve efficiency and carry heavier batteries.
When designing a long range ultralight drone the goal is to gracefully carry a larger heavier battery to enable longer flight times and be as efficient as possible with every Watt of power.
The LR5 is designed to use 5" biblade props (or lightweight triblade props) with 2004 or similar sized motors. Thsi combination provides plenty of thrust to carry large Li-Po packs (~1500mAH 4S or ~1000mAh 6S) or a 6S 28650 Li-ion pack for the longest flight durations.
Narrow but relatively thick arms optimize the vibration perfromance of the frame ensuring smooth and jello free long range cruising with no props in view. They also enable the LR5 to transform into an acrobatic marvel with a lighter battery (6S 600mAh or 4S 1000mAh). Why limit yourself to slow cruising when you can have a platform that can do it all?
THE CHALLENGE
The Achilles' heel of the 5" Long range? Not any more.
Vibrations limit flight performance
One of the key limitations with 5" long range frames is their tendancy to resonate. These frames use very thin carbon fibre arms combined with relatively large motors for their weight to swing larger 5" props.
Even the cleanest motors and props produce large amounts of vibration in flight. These vibrations excite the resonant modes of the frame amplifying vibrations at certain frequencies, increasing their amplitude and energy. These vibrations pass into the gyro and create noise on the signal. This noise requires additional filtering and limits maximum PID gains through motor heating. It also creates jello in HD footage and visibile twitches in flight.
The AOS LR5 is engineered to solve this key problem to eliminate jello, twitches and oscillations and to improve flight performance.
THE DESIGN
Understand the design methodology behind the AOS LR5
Harmonic analysis is the key
I used Blackbox logging and harmonic analysis to visualize the vibrations of the AOS LR5 during the design process. This allowed me to tune the geometry of every part of the frame, moving the frame resonances up and separating them as far as possible. The LR5 uses topology optimization to identify the most effective places to add material to improve the stiffness of the frame.
The result is a frame that delivers smoother video on stock settings and is easy to tune to achieve the most reponsive and locked flight feel whether for cinematic or dynamic freestyle flying.
KEY FEATURES
See the key features of the frame
Top and bottom plates
Both of these plates are 1.5mm thick to provide an optimal balance between strength, stiffness and weight.
In the 2 stack configuration there are mountings for a 25.5 or 20mm stack up front and a 30.5, 25.5 or 20mm stack in the rear as well as space for HDZero 1W VTX or DJI Air Unit.
In the 1 stack configuration there is a central 25.5 or 20mm stack mounting.
Arms
The AOS LR5 uses a truss design with a stabilising strut supporting the middle of the arm. This truss design provides enormous torsional stiffness, resolving a key source of vibration in traditional 5" long range frames. It is also enormously more effective than typical braces between the arms.
Truss structures are inherently very strong as they convert bending loads into compression and tension in the individual members. Carbon is much stronger in pure tension and compression than in bending.
The frame features motor protector features on the end of each arm to minimize the risk of damage to those expensive components. Should you ever need to replace an arm, there are only two screws to undo making arm replacement easy.
Camera Protection
Carbon camera plates are stiff, strong and light while being cheap to replace if they are damaged.
The camera plates include 2 standoffs to maximise durability and a cutout pattern that supports DJI O3 and all typical19-20mm FPV cameras.
