Stealth Rotor Blade Development

A project log for Valor Tactical Stealth sUAS

A low-cost multi-mission modular stealth UAV system

Canine-Rocket-TechnologiesCanine-Rocket-Technologies 12/21/2022 at 17:280 Comments

Stealth Rotor Blade R&D

The big part of Valor that gives its "Stealth" title is the optional stealth rotor blades! Drones are very loud creating a very distinctive buzz or whine that's easily audible and recognizable. Making a virtually silent drone is nearly impossible, at least with a quadcopter configuration. However, reducing the travel distance of the sound and masking the pitch closer to background noises is relatively straightforward. The exact methodology behind the R&D work for these blades can't be discussed in detail, but to the more technical individuals, you may have noticed some telltale details right off the bat ;)

Aerodynamics can be simulated, but until you test you simply don't know. The development of the blades involved rigorous amounts of test stand time, measuring power draw, RPM, thrust, and of course most importantly acoustics. We've taken advantage of 3D-printed props (Using SLS printers) to allow a very rapid data-driven evolutionary cycle of each version. It's more than strong enough for testing, but the final version will be made of carbon fiber.

Early spectrogram analysis of motor acoustic profile (as a control)

Early carbon fiber prop prototype 

Early dev prototype, fully FDM 3D printed (It actually survived full RPM but it was terrifying!) 

View of blade mounted on the test stand

*It's on our worktable for maintenance, all tests were conducted in a test cage 

View of stealth blade prototype not mounted on a motor

View of stealth blade integrated into motor mount assembly