Brief Summary
This video provides a comprehensive overview of designing and manufacturing drones using 3D printing, specifically stereolithography (SLA) and selective laser sintering (SLS). It covers key considerations such as balancing strength and weight, environmental durability, cost-effectiveness, and electromagnetic interference (EMI) management. The video also includes a step-by-step guide to assembling a custom 7.5-inch SLS printed drone, highlighting best practices for integrating 3D printed components with off-the-shelf hardware.
- 3D printing allows for on-the-go improvements, modifications and repairs.
- SLA 3D printing offers a wide variety of materials and specialised properties.
- SLS 3D printing creates lightweight, high-strength parts ideal for mission-critical applications.
Building Momentum & Formlabs Partnership
Henry Sullivan, Chief Product Officer at Building Momentum, introduces the company's intensive, hands-on training programs focused on emerging technologies like 3D printing for drone design and manufacturing. Building Momentum partners with Formlabs to offer end-to-end solutions for developing customised, high-performance unmanned systems for air, ground, and underwater applications. The video will examine stereolithography (SLA) and selective laser sintering (SLS) 3D printing technologies, discussing how to use each method to design and produce durable, mission-ready drones. Critical assembly techniques and a step-by-step workflow for a custom 7.5-inch SLS printed drone will also be covered.
Drone Applications
Unmanned systems are used worldwide for a broad spectrum of applications. Despite the variety of drones in service, designers and manufacturers must address several key considerations to ensure optimal performance and reliability. These considerations include balancing structural strength with minimal weight, ensuring environmental durability, managing production costs, and mitigating electromagnetic interference.
Drone Strength vs Weight
Drones must balance structural strength with minimal weight to optimise operational range and endurance. Lighter drones can fly longer and farther, but reducing weight too much can compromise durability. Tethered drones can prioritise heavier payloads like high-quality cameras, while untethered drones must carefully manage weight. Traditional FPV drones use carbon fibre frames, which offer excellent strength-to-weight ratios but limit design complexity. 3D printing allows for improvements, modifications, and repairs on the go, without slowing down operations.
3D Printing Technology for Drones
Using 3D printing to design and produce drones allows for on-the-go improvements, modifications, and repairs, without slowing down operations. SLA 3D printing offers the greatest material variety and specialised properties like impact resistance, high temperature tolerance, rigidity, and electrostatic dissipation. SLS 3D printing, with materials like Formlabs Nylon 12 Tough Powder, creates lightweight, high-strength parts ideal for mission-critical applications. The self-supporting nature of SLS printing enables complex, organic structures that traditional machining cannot achieve, making these materials perfect for drone frames, enclosures, brackets, and sensor housings.
Drone Environmental Durability
Environmental exposure is a primary concern in drone design, as drones operate in diverse conditions, from harsh sunlight to heavy rain and submerged environments. Durability against UV exposure and moisture is critical for long-term reliability. 3D printed materials can degrade over time due to prolonged UV exposure. Moisture-resistance is important for drones in rain or high-humidity environments, and for unmanned underwater systems facing continuous water pressure. SLA 3D printed parts are fully isotropic and inherently waterproof, making them ideal for sealed enclosures and submersible drone applications, even up to 5000 psi. SLS 3D printed parts, while durable and lightweight, can absorb moisture over time, especially under pressure, but post-processing techniques like cerakoting or resin infiltration can significantly reduce water absorption.
Drones Cost + Scalability
Drone production costs vary significantly depending on application, scale, and fabrication methods. Mass-produced FPV drones leverage economies of scale, but for defense, industrial, and specialised use cases, 3D printing enables an agile workflow that reduces lead times and shores up the supply chain. For low to medium production volumes, 3D printing is often more cost-effective than traditional machining or injection moulding, which can require expensive tooling. For high volume production, injection moulding becomes more viable, but the high initial investments in tooling make it cost-effective only for extremely large runs. Additive manufacturing bypasses traditional procurement bottlenecks, enabling on-demand, field-adaptable production without long lead times.
Drones EMI Shielding & RF Transparency
Drones require careful electromagnetic interference (EMI) and radio frequency (RF) management to ensure reliable communication, navigation, and sensor performance. Nylon 11 carbon fibre has been validated for EMI shielding and is used by major defense contractors for tactical unmanned aerial systems. Formlabs offers an open material license for the Fuse series, enabling experimentation with different sintered powders for specialised applications like RF transparency. These materials are ideal for enclosures and components requiring signal permeability, such as GPS housings, radio transparent domes, and sensor covers. TPU 90A, with its flexible properties, is useful for soft mounting RF-sensitive electronics, reducing vibration and ensuring clear signal reception.
Drones Ease of Assembly
SLS is a fantastic platform for drone frames due to its modular design, allowing for easy replacement of arms and components. The design allows high power components to be placed near the front without affecting sensitive RF components towards the back. Nylon 12 Tough powder provides similar weight, stiffness, and durability to other manufacturers' 7.5-inch drones. The drone frame components, including arms, main body, and mounting, are 3D printed, while the electronics inside are commercial off-the-shelf (COTS) with a fully NDA-compliant stack and RC link.
Drone Assembly Process: Step 1 - Attach Motor Arms to the Base
The drone assembly process begins by connecting the motor arms to the base. M3 screws are dipped in a tiny bit of Loctite to secure them. The screws are left slightly loose to ensure correct alignment before tightening them down. The drone base has slots that capture the square nuts, simplifying the process of securing the arms. The drone design is fully parametric, allowing for easy modification of features.
Drone Assembly Process: Step 2 - Mount the Stack into the Mounting Board
The next step involves mounting the stack onto the mounting board. Flush mount screws with pre-designed countersink holes are used to ensure the screws lay flat on the bottom of the mounting board, maintaining a precise fit to all the assembled components. This ensures a secure and streamlined assembly.
Drone Assembly Process: Step 3 - Install the VTX (Video Transmitter)
To install the VTX, a brass nut is placed around the threaded SMA connector and tightened to mount the antenna connector to the frame. Before positioning the VTX onto the frame, screws are pushed through the bottom of the mounting board to match the mounting pattern of the VTX. Spacers are used to ensure adequate airflow around the electronic speed controller (ESC) to prevent overheating. The VTX is then secured to the mounting board with the spacers in place.
Drone Assembly Process: Step 4 - Mount the Camera
The camera is mounted using a camera mount printed in TPU 90A powder, which is elastomeric and behaves like rubber, making it excellent for vibration dampening. The camera mount is placed on the mounting board, and the camera is secured with small screws included in the VTX kit. This ensures the camera is stable and protected from vibrations during flight.
Drone Assembly Process: Step 5 - Mount the Motors
Attaching the motor securely is essential. Loctite is applied to the tips of the screws, and a washer is used to distribute the force of the screw going through the nylon material. The screws are kept slightly loose to ensure proper alignment before fully tightening them. The nylon locking nut included with the motor is added onto the motor shaft, but kept loose.
Drone Assembly Process: Step 6 - Wire Management
Organising the build by zip tying, electrical taping, or using wire channels to secure the motor wires to the drone arms is good practice. Slack is removed when possible to avoid mistakes in the assembly process and reduce the risk of a prop getting caught in a stray wire. Proper wire management ensures a clean and safe build.
Drone Assembly Process: Step 7 - Install the ESC (Electronic Speed Controller)
The ESC is mounted with the main power pads towards the front of the drone. The drone build is designed to be field serviceable, allowing the drone battery to serve as the power supply for a field soldering iron. Flux is applied to the pads to ensure a quality solder joint. Solder is added to the desired pad by applying heat to the pad first, then adding the solder. The wire is trimmed to the desired length and wrapped around the screws for better organisation.
Drone Assembly Process: Step 8 - Install GPS and RC Antenna
The GPS module is mounted into the TPU mount before connecting the supplied cable. A small tool is used to clear out any additional powder if needed. The UFL connector end of the RC receiver antenna is pushed through the hole in the underside of the TPU mount, using a small tool if necessary. One of the antenna holes on the backside of the TPU mount is cut to allow for the RC antenna to mount without breaking or bending. The GPS cable is twisted to make it easier to push through the frame, reduce EMI, and add a polished look.
Drone Assembly Process: Step 9 - Install the Power System
A frame mounted XT60 connector is used for easy connection and disconnection of the power source. The 12 gauge red and black wire is cut to length, and the ends are stripped and tinned. One end is soldered to the XT60 connector, ensuring the flat side is positive. Heat shrink is added to minimise the risk of short circuits. The XT60 connector is mounted directly onto the frame using M3 hardware, and the power cables are routed back to the ESC. The wires are then soldered to the ESC's main power pads.
Drone Assembly Process: Step 10 - Install the Flight Controller
The process of mounting the flight controller on top of the ESC begins. The ESC needs to communicate with the flight controller to receive motor commands. The flight controller is flipped upside down and placed onto the mounting screws for easier access to the solder pads. Solder pads are prepared to connect the GPS module by cleaning and tinning those pads. The radio that receives all the pilot commands also needs to be soldered to the flight controller. The wires are tinned, and the proper pins are connected to the correct pads, referring to the manufacturer's pin/wiring guide to ensure proper connections.
Drone Assembly Process: Step 11 - FAA Rules and Regulations
As required by the FAA, a remote ID must be used if flying commercially, but is not needed if flying recreationally under 250 grams. The remote ID module is attached by soldering the positive and negative wires to an available 5 volt and ground pin pair on the flight controller. This ensures compliance with regulations for commercial drone operations.
Drone Assembly Process: Step 12 - Place Cover
The SLS printed cover is placed on top of the mounted board. The design uses slots for airflow and cable routing. The remote ID power cable is routed through one of these slots. This cover protects the internal components while allowing for necessary ventilation and cable management.
Drone Assembly Process: Step 13 - Finishing Touches
The FPV antenna is attached. The propellers are placed on the motors and secured with nylon locking nuts, which are then tightened with a wrench. The battery pack is secured with velcro straps, and the balance lead of the battery is taped out of the way to prevent it from getting tangled or nicked by any of the propellers.
Drone Assembly Process: Step 14 - Fly
By applying these design and assembly strategies, the drone remains lightweight, durable, and easy to maintain while taking full advantage of the flexibility that additive manufacturing provides. These strategies ensure optimal performance and longevity of the drone.
How to Learn More & Contact Us
To learn more about the Fuse Series SLS ecosystem, contact the Formlabs Aerospace and Defense Team. To learn more about Building Momentum's custom additive manufacturing curriculum, including drone design, manufacturing, and operations, visit buildmo.com.
