Ever wondered what it takes to build a drone that defies windy conditions with remarkable stability and agility? The video above showcases an impressive initial test flight of a custom-built Twin Tricopter (TT) with a heavy frame, demonstrating its raw power and maneuverability. This project highlights the dedication and technical skill involved in pushing the boundaries of RC flight, especially when dealing with unique designs and challenging environmental factors.
Unpacking the Twin Tricopter (TT) Design
A tricopter is a unique multirotor aircraft, distinguishable by its three rotors, unlike the more common quadcopter with four. The primary advantage often lies in its mechanical yaw control system, which typically involves a tilting servo for the rear motor. This design can offer exceptionally precise and responsive yaw, often leading to a more “locked-in” feel during flight.
The Twin Tricopter (TT) featured here takes this concept further, implying a specialized or reinforced design, possibly for increased payload capacity or improved aerodynamics. The builder specifically mentions a “heavy frame.” While heavy frames can provide durability and reduce vibrations, they also demand more power and careful tuning to achieve optimal flight performance. This trade-off between robustness and agility is a common challenge for custom drone builders.
Conquering the Wind: A Test of Stability
One of the most impressive aspects of the TT’s initial flight was its performance in significant wind. The speaker notes “very gusty wind today, too. Steady wind of about ten miles, gusts of up to about twenty, twenty-five miles.” These conditions are formidable for any drone, often leading to instability, wobbling, and difficulty maintaining position. For a custom build, successfully navigating such winds is a testament to its design and the builder’s tuning prowess.
The video clearly shows the Twin Tricopter remaining “rock solid in the wind,” exhibiting far less wobble than a typical quadcopter might. This superior stability in adverse conditions is a key reason many enthusiasts are drawn to tricopters. Their unique thrust vectoring system, especially the tilting rear motor, provides an inherent advantage in counteracting external forces like strong gusts, allowing for a more controlled and predictable flight experience.
The Art of Tuning: Achieving “Milder Side” Flight
Before this successful flight, the TT was “really wild,” indicating a need for significant adjustments. The builder mentions tuning it “on the milder side.” This refers to tweaking the flight controller’s PID (Proportional-Integral-Derivative) gains. PID tuning is a critical process where various parameters are adjusted to control how the drone responds to errors in its orientation and position.
A “wild” drone might have excessively high proportional gains, leading to overcorrections and oscillations. Tuning to the “milder side” often involves reducing these gains slightly to smooth out responses, making the drone less aggressive but more stable and easier to control. This iterative process of flying, observing, and adjusting is fundamental to optimizing any multirotor’s performance, especially one with a unique configuration like the Twin Tricopter.
Powering Performance: The 3S 20C Battery and Throttle Management
The Twin Tricopter is running off a “three S, twenty C” battery. Breaking this down, “3S” indicates a 3-cell series LiPo (Lithium Polymer) battery, which provides a nominal voltage of 11.1 volts (fully charged around 12.6V). “20C” refers to the continuous discharge rate, meaning the battery can safely deliver current at 20 times its capacity. For example, a 2200mAh 3S 20C battery can provide a continuous 44 amps (2.2 Ah * 20C).
The builder states they were pushing the throttle “only about seventy-five percent.” This observation is crucial for several reasons. First, it suggests the motors and propellers are well-matched to the heavy frame, providing ample power even at partial throttle. Second, having headroom in the throttle range means the drone has significant reserve power for quick maneuvers, ascent, or battling strong gusts. Maintaining stable hover at 50-70% throttle is generally considered efficient and indicates a well-balanced power system for the drone’s weight.
Flight Controller Insights: The KK2 Board and the Missing Magnometer
The Twin Tricopter uses a “KK2” flight controller. The KK2 board was a popular, entry-level flight controller known for its ease of use and on-screen display (OSD) for tuning without needing a computer. It was a favorite among hobbyists for its simplicity and robustness, making it ideal for custom builds and learning about PID tuning.
However, the speaker expresses a wish that the “KK2 had a magnometer.” A magnometer is a digital compass that provides heading information, allowing a flight controller to maintain a specific direction independently of GPS. Without a magnometer, the drone relies solely on its accelerometers and gyroscopes for orientation, which can lead to “yaw drift” over time, especially in tricopters due to their single yaw motor. Integrating a magnometer, either built-in or externally, would significantly enhance the drone’s ability to hold a stable heading, making advanced flight modes and autonomous capabilities more precise.
Agility and Speed: The Tricopter’s Natural Strengths
Despite the heavy frame and gusty wind, the Twin Tricopter demonstrated impressive performance. “Very maneuverable. Very fast,” the builder exclaimed. This inherent agility is a hallmark of the tricopter design. The ability of the rear motor to tilt provides direct thrust vectoring for yaw control, which is often perceived as more immediate and precise than the differential thrust used by quadcopters for yaw.
This direct mechanical control contributes to the Twin Tricopter’s responsiveness, allowing for sharp turns and rapid changes in direction, even when battling the elements. The combination of a powerful motor system (evidenced by the 75% throttle observation) and the tricopter’s unique yaw mechanism creates a platform capable of both robust stability and exhilarating speed.
Addressing Build Quirks: The Tail Rubbing Incident
During the flight, a distinctive sound was noted: “Oh, did you hear that? The tail is turning so sharp that it’s rubbing against my wooden frame.” This is a common occurrence in custom builds and highlights the importance of precise mechanical clearances. When the rear servo-controlled motor tilts to provide yaw, the propeller or motor housing can sometimes come into contact with the frame if not enough space is provided.
This issue, while minor, suggests a need for a slight modification. Solutions could include:
- Adjusting the servo throw limits on the flight controller to prevent excessive tilt.
- Modifying the wooden frame to create more clearance.
- Selecting a slightly smaller propeller for the rear motor.
- Ensuring the motor mount and servo arm are optimally positioned.
Such small mechanical adjustments are typical in the iterative process of building and refining a custom Twin Tricopter or any multirotor project.
Debriefing the Maiden Flight: Your Twin Tricopter TT Heavy Frame Questions
What is a tricopter?
A tricopter is a type of drone that has three rotors, which is different from a quadcopter that has four. It often uses a tilting rear motor for precise steering control.
Why are tricopters good in windy conditions?
Tricopters can handle wind well because their unique design, especially the tilting rear motor, helps them actively counteract strong gusts. This leads to better stability and a more controlled flight.
What does it mean to tune a drone to the ‘milder side’?
Tuning a drone to the ‘milder side’ means adjusting its flight controller settings to make it less aggressive in its movements. This results in smoother responses, making the drone more stable and easier to control.
What is a KK2 flight controller?
The KK2 is a simple and popular flight controller often used by hobbyists because it’s easy to use. It allows you to tune the drone’s settings directly on its screen without needing a computer.
