A drone gimbal consists of drive motors, mechanical brackets, a control board, attitude sensors, and a power supply system. Its motors rotate the camera along different axes, while sensor feedback and control algorithms compensate for vibration and changes in aircraft attitude during flight. Building a gimbal involves material preparation, mechanical design, control programming, and assembly and testing. Each stage must be completed properly to ensure smooth axis movement and stable camera operation.
Materials and Components Required for Building a Drone Gimbal
A basic 2-axis drone gimbal generally requires the following components.
Servo Motors
At least two servos are required for a 2-axis gimbal, typically controlling the pitch and roll axes. Motor selection should be based on camera weight, center of gravity, and required motion range. Output torque and operating speed must both meet the application requirements.
Digital servos with position feedback can be considered. Some models also support magnetic encoder feedback or digital bus communication, providing additional positioning and control capabilities.
The DS3225 mentioned in the original material is a digital RC servo that can be considered as a drive component. However, a standard digital servo and a digital bus servo are not the same. Its communication interface and position feedback functions must be checked before selection.
Main Control Board
The control board receives attitude sensor data, runs the control algorithms, and sends movement commands to the servos. Common choices include STM32 and Arduino development boards.
The board should provide sufficient PWM output channels and serial communication interfaces for the project. A suitable development environment, such as Arduino IDE or Keil, is also required for programming and debugging.
Power Supply System
The power supply must match the operating voltage and current requirements of the selected servos. Small servos commonly operate at approximately 5V to 7.4V, but the actual voltage range must be confirmed using the corresponding product datasheet.
A Battery Eliminator Circuit (BEC) can be used to provide regulated power to the servos. The design must account for peak current during startup and changes in load. The peak current of a single servo may reach 1A or higher. An insufficient power supply can cause voltage drops and affect servo response and gimbal stability.
Mechanical Components
The mechanical structure mainly consists of servo brackets, camera mounting plates, shaft connectors, and other fastening components. Aluminum alloy and carbon fiber are common material choices because they provide a balance between structural stiffness and overall weight.
For prototype development, 3D-printed components can also be used. PLA and nylon are two common choices for adjusting mounting dimensions and structural layouts during testing.
Wiring and Auxiliary Components
Additional materials include Dupont wires, screws, nuts, and counterweights. M2 to M3 fasteners can be selected according to the structural dimensions.
Counterweights are used to adjust the center of gravity of the camera and gimbal assembly, reducing the additional load placed on the servos during operation.
Mechanical Design of a Drone Gimbal
Mechanical design should be based on camera dimensions, weight, installation space, and required motion range. A suitable axis arrangement and balanced center of gravity help reduce uneven motor loading and improve operating stability.
Determine the Dimensions and Payload
First, measure the camera's overall dimensions and weight. The servo brackets and mounting plate can then be designed according to the camera installation requirements. For example, the original material gives a reference weight range of 100g to 200g for the GoHero camera series.
The servo output torque must be sufficient to support the camera and its mounting structure, with an appropriate allowance for dynamic operation. Actual load capacity should not be determined solely by the servo's maximum stall torque.
Adjust the Camera Center of Gravity
The camera's center of gravity should be positioned as close as possible to the corresponding rotation axis. This reduces the torque generated by the camera's weight and lowers the continuous torque required from the servo to maintain its position.
When the center of gravity is too far from the rotation axis, the servo must continuously generate greater torque to hold the camera in position. This increases motor loading and may affect gimbal smoothness.
Design the Rotation Mechanism
Two common drive arrangements can be used in a gimbal:
Direct drive: The servo output shaft connects directly to the moving gimbal component. This arrangement has a relatively simple structure and is suitable for basic gimbal designs.
Gear transmission: A gear train transfers power between components and allows the transmission ratio to be adjusted according to the design. Backlash must be controlled to prevent positioning errors.
Bearings or linear guides can be used at rotating and supporting positions, depending on the load and structural arrangement. These components help reduce friction and improve movement smoothness.
A 2-axis gimbal should also have mechanical travel stops to prevent the axes from exceeding their designed motion ranges and to avoid cable twisting during rotation.
Mounting and Vibration Isolation
Rubber vibration dampers or silicone pads can be installed between the servos and mounting brackets to reduce the transmission of high-frequency vibration to the camera assembly.
The main supporting structure must also have sufficient stiffness. Loose connections or bracket deformation can affect axis alignment and positioning accuracy.
Control Programming for a Drone Gimbal
After completing the mechanical design, the control program must be developed to adjust servo angles according to changes in attitude. A common approach uses an Inertial Measurement Unit (IMU) to collect attitude data and a PID control algorithm to calculate the required servo adjustments.
The program generally includes the following functions:
Servo initialization: Move the servos to their predefined neutral positions when the system starts and check that each axis is operating normally.
Command reception: Receive commands from the flight controller, remote controller, or host computer through PWM signals or serial communication.
Attitude data acquisition: Use gyroscopes and accelerometers to detect changes in the attitude of the gimbal or UAV.
PID angle control: Calculate the control output from the deviation between the target angle and the measured attitude, then adjust the servo direction and position.
Data filtering: Filter sensor data to reduce the effect of noise on control results and prevent unnecessary small servo movements.
When servos support external position feedback, an encoder can also be used to measure the actual rotation angle and provide additional position feedback. Standard PWM servos do not necessarily provide externally accessible encoder data, so this function should not be assumed for every digital servo.
Assembly and Testing of a Drone Gimbal
After completing the mechanical structure and control program, the entire gimbal must be assembled and tested. The main tasks include:
Servo installation: Install the pitch and roll servos according to the design arrangement. Check the alignment between the output shafts and connecting brackets, and secure the wiring.
Motion range inspection: After powering up the system, calibrate the neutral positions and test the rotation range of each axis. Confirm that there is no mechanical interference or cable twisting during movement.
Control parameter adjustment: Install the actual camera payload and test the stabilization performance. Adjust the PID parameters according to image movement and servo response.
Power supply and operating checks: Monitor servo current and operating conditions at different positions. Confirm that the supply voltage remains stable and that the drive components do not show abnormal heating or continuous oscillation.
After these tests, evaluate the gimbal under actual flight conditions to confirm that the mechanical structure, drive system, and control program operate together as intended.
Custom Machining of Precision Parts for Drone Gimbals
Drone gimbals contain servo brackets, camera mounting plates, shafts, connecting components, and other precision mechanical parts. Their machining requirements depend on camera dimensions, axis arrangement, and mounting interfaces. Hansheng Automation provides custom precision machining based on customer drawings and accepts both single-piece and small-batch orders.
In addition to structural components for drone gimbals, our machining services also cover precision parts for yachts, tobacco packaging machinery, RC racing cars, and filling equipment. Components are manufactured according to the structural requirements and drawings provided for each project.
