Italy-based CRP Technology, part of the larger CRP Group, has used its versatile Windform composite materials and SLS 3D printing technology to manufacture everything from masks and golf drivers to motorcycle components and drone prototypes.
In a new case study, we’re getting a closer look at the 3D printed Tundra-M, the functional prototype of Hexadrone’s first modular, easy-to-use unmanned aerial system (UAS) drone that we saw first-hand at CES 2018.
According to the case study, “Additive Manufacturing technologies in UAS applications has presented both opportunity and challenges to engineers in the field.”
The rugged Tundra-M, Hexadrone’s first mass-produced drone, has a waterproof design and was built for industrial and multi-purpose tasks in extreme weather conditions.
“We have engineered our drone by means of a cautious, multifaceted, and collaborative based approach with the involvement of broad-based stakeholders,” said Hexadrone CEO Alexandre Labesse. “In the course of two years of consulting, research and development we have gathered all the advice and customers’ testimonials useful to its design and which finally helped us in the process of devising an ideal UAV solution.”
3D printing offers engineers more design flexibility than traditional manufacturing methods, and can reduce both the timeline and costs for projects like the Tundra-M prototype, which was, as the case study notes, “conceived around a multifunction perspective.”
A faster iteration generation and timeline, coupled with the system optimization made possible due to the polyamide-based, carbon fiber-reinforced Windform XT 2.0 and Windform SP composite materials, are exactly what drew Hexadrone to CRP Technology.
“The Windform selective laser sintering technology allowed us to easily prototype key components of our product, to outcompete the plastic injection molding process in terms of deadlines, cost, and to test our prototype in real life conditions with almost the same mechanical characteristic,” said Labesse.
“The project we have designed with these two materials, the Windform SP and the Windform XT 2.0 from CRP Technology, lies in the conception of different frame parts, junction parts, a quick release patented system as well as the components forming our patented carbon-made arm system. This 3D printing time/cost saving technology helped us a lot and now allows us to calmly approach the mass production phase.”
- Consistent results
- Fast iteration process
- Best ratio between structural strength and weight
- Chance to combine multiple functionalities in one part
“Regarding the most innovative aspect of Laser Sintering technology with Windform materials, lies in the possibility to prototype with all the pros of the plastic injection process without the cons this method entails in terms of cost and deadlines,” said Labesse. “Furthermore, Windform provides us with a close enough material in terms of properties (eg, density, colour, tensile strength, modulus, elongation at break etc).”
CRP’s technology and Windform materials overcame multiple issues, including vibrations and compressive, tensile, and traction stresses. One of the biggest problems while designing the Tundra-M was a scale gain between 0.15 and 0.20 mm, due to lack of precision – if this isn’t anticipated ahead of time, the gain can cause part assembly issues.
Because of its thermal and mechanical properties, Windform SP was used to make the body frame of the Tundra-M, which contains the circuit boards and cooling system and has a removable lid.
“To devise this component, we were in need of a water-resistant, durable and sturdy material,” explained Labesse. “Moreover, this sturdy frame comes with an emergency parachute, four removable and scalable arms, two batteries as well as three easily interfaceable accessories.”
Four removable arms support the frame, which can be switched quickly to make the drone easy to maintain and flexible enough to meet multiple professional needs and flight scenarios; the arms also have three accessory connections, which make it a pliable and effective tool. Windform XT 2.0 was used to 3D print the arms, which are made up of motor supports and an interlock base – this makes them easy to tighten with the support of a stiff “tension ring” system.
“Our patented technology offers a reliable and sturdy connection while being a waterproof solution in case of inclemency,” Labesse said. “This interlocking connection is also able to handle the stress due to leverage forces. Those leverage forces are primarily generated through the components at the end applying a constant force through masses.”
Hexadrone carried out numerous tests on the Tundra-M prototype drone, including flight tests in real service conditions to see if the mounted parts could handle the varying strains encountered throughout different flight scenarios, and landing tests, so the folding and unfolding of the landing foot structure that supports the drone’s full weight could be checked. Additionally, Hexadrone completed assembly and disassembly tests of the parts to test their structure and the Windform materials’ fatigue resistance.
The Tundra-M performed admirably, thanks in large part to the high-quality mechanical components and their “intrinsic material qualities.” The lightweight Windform materials used to 3D print the prototype were flexible and compatible enough to make the drone a good choice for demanding applications, and they cost less than using plastic injection technology for prototyping. Additionally, CRP’s SLS technology produced no flaws or undercut, which is great for prototypes, as the case study mentioned that you can often notice flaws on industrial pieces made with plastic injection molding.
Hexadrone also noted the materials’ neutral color and texture, along with the moisture resistance they provided, as major advantages, as well as CRP’s ability to provide access to the cost-effective 3D printed parts within short project deadlines.
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[Images provided by CRP Technology]