3D Printed Heavy Load Remote Controlled Quick Release Hook for Drone
- Misha Herschorn
- Jul 24
- 9 min read
When we needed a strong, remotely controlled payload release system for demanding drone operations, we decided to design and build our own.
The result is our 3D Printed Heavy Load Remote Controlled Quick Release HooK. A modular system designed to carry a suspended payload beneath a drone and release it on command.
The hook was developed for real world aerial delivery work, tested through 50 controlled release cycles with a 50 lb (22.7 kg) load, and used as part of our payload delivery system during the production of Extracted Season 2.
The system is available in two formats:
Digital 3D print files
A fully assembled product
Purchase the 3D-print files:
Purchase the fully assembled quick release hook:
Designed for Remote Drone Payload Releases
The quick release hook provides a practical way to secure, carry and remotely release an external drone payload.
The system uses a standard size servo to move a mechanical locking pin. When the operator activates the assigned control from the transmitter, the servo shifts the locking mechanism and allows the hook to open.
The hook is built from several individually printed parts, making it easy to replace a single component rather than rebuilding the entire system. The battery, receiver and control electronics are housed in a separate 3D printed enclosure connected to the hook.
This modular design offers several benefits:
Damaged or worn parts can be printed individually.
Print settings can be adjusted to balance weight and strength.
The electronics remain protected inside a dedicated enclosure.
The system can be integrated into different drone and payload-mounting configurations.
Builders can source commonly available RC electronics rather than relying on proprietary components.
Tested at 50 lb for 50 Release Cycles
We tested the quick release hook with a 50 lb, or 22.7 kg, suspended load under controlled conditions.
The hook completed 50 consecutive holding and release cycles at 50 lb without a structural failure during the test.
This testing demonstrates what our specific build accomplished using our materials, hardware, print settings and assembly methods. It does not establish a certified maximum load or safe working load rating.
The product should therefore be described as:
Tested through 50 controlled release cycles with a 50 lb load. No certified load rating or performance guarantee is provided.
Variations in printer calibration, material quality, layer adhesion, orientation, hardware, assembly and wear can significantly affect the strength of a 3D printed part. Anyone building or buying the full assembled hook must conduct independent ground testing before using it on a drone.
Watch the 50 lb test video: https://vimeo.com/1209961743/ce9fb5aa19?fl=ip&fe=ec
Used on Extracted Season 2
This quick release hook was developed for more than workshop testing. We used it as part of our aerial delivery system during the production of Extracted Season 2.
First Class Drones was brought in to deliver supply crates to contestants positioned throughout remote forest locations. The operation used the Freefly ALTA X and required stable flight with suspended payloads, precise navigation, accurate positioning and a controlled remote release.
Before each flight, the payload and release system were tested on the ground. Once the aircraft reached the delivery area, the ALTA X was stabilized directly over the designated drop zone before the release was activated. A downward facing camera and live aircraft telemetry helped confirm alignment, clearance and hover stability before each deployment.
Using the system in a professional production environment helped confirm the value of a quick release that is straightforward to inspect, easy to operate and built from individually replaceable parts.
Read more about the operation in our article, Flying the ALTA X for Aerial Deliveries on Extracted Season 2.
How the Electronics Work
The system uses a TBS Crossfire radio link to send the release command to the hook.
The signal path is:
Compatible Crossfire transmitter → TBS Crossfire Nano RX → Matek CRSF-PWM-6 → MG995 servo
The Crossfire Nano RX receives the command from the operator’s transmitter and sends a CRSF signal to the Matek converter. The converter translates that signal into the standard PWM output required by the servo.
The power path is:
External battery → LM2596 regulator set to 5V → Receiver/CRSF-PWM-6 → Servo
Power enters the enclosure through an XT60E-M panel-mount connector. The LM2596
step down regulator reduces the battery voltage to the regulated 5V supply used by the electronics.
Hardware and Electronics Used
MG995 Metal Gear Servo
The release mechanism uses an MG995 standard size, 180-degree metal-gear servo.
The servo is installed using the standard mounting bracket that comes with the servo and servo arm supplied with the servo kit. Its movement controls the printed linkage and locking pin that secure and release the hook.
TBS Crossfire Nano RX
The TBS Crossfire Nano RX receives the release command from a compatible Crossfire transmitter or transmitter module. The receiver operates from 3.3V to 8.4V, allowing it to run from the regulated 5V supply used in this build. It communicates with the Matek converter using the CRSF protocol.
Matek Systems CRSF PWM 6
The build uses the Matek Systems CRSF-PWM-6 to convert the CRSF receiver signal into a PWM output for the servo. The board provides six configurable PWM outputs. It does not contain a built in 5V regulator, so the board and connected servo must be supplied with an external regulated 5V power source.
LM2596 Adjustable Voltage Regulator
A Valefod LM2596 DC-to-DC step-down converter is used to regulate the external battery voltage down to 5V.
The module is listed for an input range of 3.2V to 35V and an adjustable output of 1.25V to 30V. However, it is a step-down converter and cannot increase voltage. Its input must remain approximately 1.5V above the selected output voltage. When configured for a 5V output, the practical input must therefore be approximately 6.5V to 35V.
Before connecting the receiver, converter or servo, the regulator must be adjusted to 5V and verified with a multimeter. The output polarity must also be confirmed.
XT60 Panel Mount Power Connector
Power is connected through an XT60E-M panel-mount male connector installed in the electronics enclosure.
The connector package used in our build includes the XT60E-M panel-mount connector with screws.
Connector used: LINSYRC XT60E-M and XT60 connector set.
Mechanical Hardware
The remaining assembly uses commonly available hardware:
4x M3 30mm button head socket cap screws for electronics box
4x M3 nuts for electronics box
4x M4 16mm self tapping screws for joining hook assembly
1x M4 12mm self tapping screws for hook turning mechanism
4x M3 8mm button head socket cap screws for servo mounting
2x M3 14mm button head socket cap screw for servo to turning mechanism bar
2x M3 nut for servo to turning mechanism bar
1x M3 6mm button head socket cap screw for servo arm. Should come with servo
1000lb Paracord Rope, 4mm
Standard servo bracket and servo arm
Suitable wiring and connectors
Solder and heat shrink tubing
A suitable external battery
A heavy-duty carabiner or another appropriate attachment device
Finished Weight
When printed using the recommended high strength settings below, the complete system weighs approximately 450 grams.
This weight includes:
The printed hook assembly
Servo and linkage
Electronics enclosure
Receiver and control electronics
Wiring
A relatively heavy duty carabiner
The approximately 450-gram weight does not include the battery.
The final weight will vary depending on the selected filament, hardware, servo, wiring, connector, battery and carabiner.
Adjustable Strength and Weight
One advantage of a 3D printed system is the ability to change the print settings for different applications.
For maximum strength, we recommend following the high infill settings used for our tested version. These settings use PETG, high infill and increased perimeter counts on the structural components.
Builders carrying substantially lighter payloads may choose to reduce infill to lower the finished weight. However, reducing infill or perimeter counts will also reduce the expected strength and durability of the hook.
A lighter version should not be assumed to perform like the version tested at 50 lb. Any change to the material, scale, infill, perimeter count or print orientation requires independent testing.
Included With the 3D Print File Package
The digital download includes:
All quick release hook part STL files
Quick Release Hook Battery and Electronics Side #1.stl
Quick Release Hook Battery and Electronics Side #2.stl
Quick Release Hook Battery and Electronics Plug.stl
A folder containing the individual STL files for all hook components
Assembly video
Recommended print settings
Print modifier reference images
Product Safety Notice and Liability Disclaimer
The digital download contains the print files and instructions only. The servo, receiver, converter, regulator, connectors, hardware, wiring, battery and carabiner must be purchased separately.
Customers who do not want to print and assemble the system can purchase a fully assembled version.
Recommended Print Settings
Print orientation, perimeter count, infill and modifier placement are critical to the strength of the finished assembly. Refer to the included reference images for the exact modifier locations.
Quick Release Body Side 1 and Side 2
Files
Quick Release Body Side 1.stl
Quick Release Body Side 2.stl
Settings
Material: PETG
Infill: 90–100%
Infill pattern: Cubic
Perimeters: 6
Supports: Everywhere
Modifier: 3 perimeters in the area shown in the included reference image
Quick Release Hook
File
Quick Release Hook.stl
Settings
Material: PETG
Infill: 90–100%
Infill pattern: Cubic
Perimeters: 8
Supports: Everywhere
Quick Release Locking Pin and Servo Bar
Files
Quick Release Locking Pin.stl
Quick Release Servo Bar.stl
Settings
Material: PETG
Infill: 90–100%
Infill pattern: Cubic
Perimeters: 4
Supports: Everywhere
Quick Release Turner Attachment
File
Quick Release Turner Attachment.stl
Settings
Material: PETG
Infill: 90–100%
Infill pattern: Cubic
Perimeters: 3
Supports: Everywhere
Battery and Electronics Enclosure
Files
Settings
Material: PETG
Infill: 25%
Infill pattern: Cubic
Perimeters: 5
Supports: Everywhere
Modifier: 4 perimeters and 90–100% infill in the area shown in the included reference image
The enclosure does not need to be printed entirely at the same infill level as the structural hook components. The modifier reinforces the required area while helping reduce the enclosure’s overall weight.
Battery and Electronics Plug
File
Quick Release Hook Battery and Electronics Plug.stl
Settings
Material: TPU
Infill: 25%
Infill pattern: Cubic
Perimeters: 3
Supports: Everywhere
The flexible TPU plug allows the enclosure to be opened so you can bind the crossfire reveiver.
Assembly and Preflight Testing
This is a multi-part mechanical and electronic system intended for builders who are comfortable with 3D printing, soldering, RC electronics and drone payload integration.
Before mounting the system to an aircraft:
Inspect every printed component for cracks, incomplete layers, deformation or poor adhesion.
Confirm that all hardware is secure.
Verify that the locking pin fully engages.
Confirm that the servo and linkage move freely without binding.
Set and verify the regulator’s output at 5V with a multimeter.
Confirm the correct polarity before connecting the electronics.
Bind the receiver and configure the assigned release control.
Configure and test an appropriate failsafe position.
Test the mechanism repeatedly without a load.
Conduct progressive ground testing with gradually increasing weight.
Verify the drone’s payload capacity, centre of gravity and available thrust margin.
Confirm that the payload and release mechanism cannot contact the propellers, landing gear or aircraft structure.
A successful ground test does not eliminate the risks associated with carrying or releasing an external payload from a drone. Payloads can affect aircraft balance, control response, flight time, thrust requirements and emergency procedures.
Product Safety Notice and Liability Disclaimer
This product was tested by the manufacturer through 50 controlled release cycles with a 50 lb (22.7 kg) suspended load. These results are provided for informational purposes only and do not guarantee performance.
The strength of 3D-printed parts can vary depending on factors including, but not limited to:
Printer calibration
Print orientation
Layer adhesion
Material type and condition
Nozzle and extrusion settings
Environmental conditions
Temperature and UV exposure
Wear, damage and age
Hardware selection
Installation and assembly methods
Before every use, inspect the complete system for cracks, deformation, loose fitment, damaged layers, worn components or abnormal servo movement. Discontinue use immediately if any damage or unreliable operation is observed.
This product is provided for general purpose use only. It is not certified for safety critical applications, life support applications, climbing, lifting people, overhead lifting, fall protection, towing, rescue equipment or any use in which failure could result in injury, death or significant property damage.
The user is responsible for determining whether the product is suitable for the intended application, complying with all applicable laws and aviation requirements, and conducting appropriate testing before use.
By printing, assembling, purchasing or using this product, the user acknowledges that 3D printed components can fail and assumes all risks associated with its use.
The manufacturer and seller shall not be liable for indirect, incidental, special or consequential damages arising from the use or misuse of the product.
A Practical and Customizable Payload Release System
This project represents the type of work we enjoy most at First Class Drones: combining professional flight experience, custom engineering and practical problem-solving.
The quick release hook was created for a real operational need, tested under controlled loads and used during a professional television production. Its modular design allows builders to print replacement parts, adjust the system for different applications and source readily available RC components.
Whether you are building an aerial delivery platform, developing a custom heavy lift drone or experimenting with remotely operated payload systems, this quick release hook provides a practical starting point.
Purchase the 3D print files:
Purchase the fully assembled quick release hook: https://www.firstclassdrones.ca/product-page/quick-release-hook
Watch the assembly video:
Watch the 50 lb test video:
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