A couple weeks ago, the Cincinnati, Ohio-based grocery chain Kroger made its first drone delivery less than 30 minutes from my home in Dayton, flying one mile from Centerville’s Kroger Marketplace to City Hall and delivering two bags of rice, along with a piece of fabric from the Wright Brothers’ 1903 flyer; we’re very proud of our “first in flight” heritage around here. Drones, or unmanned aerial vehicles (UAVs), can be used for all sorts of tasks, from delivering groceries, food, medical supplies, and even spare parts to surveillance, search and rescue missions, clearing land mines, and fighting fires, and 3D printing is often used to make or customize them.
This winter, global engineering community and platform Wevolver announced a partnership with Mitsubishi Chemical Advanced Materials (MCAM) to launch the KyronMAX Design Challenge, and we recently learned that the winner is an ultra-quiet UAV propeller, and that 3D printing played a part in the design.
The goal of the challenge was to create a design that uses MCAM’s KyronMAX range of high-strength carbon fiber-based composite materials to solve a manufacturing or engineering challenge, and a team of engineers from Canadian aerospace startup Delson Aeronautics won for its Ultra-Quiet Unmanned Aerial Vehicle (UAV) Blades, which promise to decrease propeller noise by an astonishing 50%, so that obnoxious buzzing sound you typically hear with drones will be no more.
In order to handle heavy loads, and be flexible enough to avoid any damage, drone propellers need to be able to generate a significant amount of lift, and herein lies the challenge that the Delson team decided to solve—finding cost-effective, lightweight, and manufacturable materials to make UAV propellers that also feature the necessary amount of flexibility, strength, and stiffness is no easy feat. Additionally, when a drone propeller spins faster to generate more thrust, the noise also goes up.
Delson engineers Michael Deloyer, Eitan Rotbart, and Ammar Jessa thought that MCAM’s injection molding technology and structural thermoplastic KyronMAX materials, with their increased mechanical properties, could help them create a better UAV propeller, and one with reduced sound as well.
Graph showing sound pressure level vs. thrust. Image courtesy of Delson Aeronautics.
When it comes to injection molding, CNC machining is often required, and depending on the complexity and size of the parts you’re making, this can really drive up costs. This isn’t as much of an issue when you’re manufacturing large batches, since the individual cost per part goes down as the number you’re making goes up, but it’s really not practical to use it for prototyping, testing, and small batch manufacturing.
Delson knew that MCAM’s KyronMAX platform could help them here, as it uses a technology called SPRINT (Soluble PRinted INjection Tooling), which involves AddiFab’s Freeform Injection Molding (FIM) process and 3D prints soluble mold inserts using photopolymer resin. Once you’ve got the 3D printed mold inserts, they can be put into the main metal mold base and then injected with molten plastic; the soluble mold is later washed in a solution that dissolves and exposes the completed plastic part, which is said to be both strong yet lightweight, as well as more affordable.
It takes just days, rather than months, to complete this process, and SPRINT also makes it possible to create complicated geometries without having to use sliding mold surfaces or complicated cam devices. In addition, KyronMAX materials, when they’re used for injection molding, can supposedly produce parts that are 40% lighter than aluminum and 75% lighter than steel. All in all, the Delson team was able to produce tough propellers with the aesthetic finish and surface qualities of injection molding and the lead time and design freedom of AM.
As the winner of the KyronMAX Design Challenge, Delson Aeronautics has received $25,000 worth of design and manufacturing support from MCAM to help develop their ultra-quiet propellers and bring the product to the commercial market.
“The team is very excited to have kicked off the program with Mitsubishi Chemical Advanced Materials and Wevolver,” said Deloyer, the Founder of Delson Aeronautics. “Their support will help show what the Delson blades are capable of and the impact they can have on the future of the UAV industry. The prize has greatly increased interest from UAV manufacturers and we are now discussing potential collaborations to help bring these blades to market.”
Delson Aeronautics test their ultra-quiet blades.
The Delson team will continue to work closely with MCAM engineers to build and test out the propeller blades, with a product release already scheduled for later this year. You can follow the project here, as their progress will be documented all the way through to the final stage of commercialization.
(Source/Images: Wevolver)