Category: Propellers

Mix and Matching Propellers Reduces Noise

It took some outside-the-box thinking by the folks at Aurora, a Boeing-owned company, to arrive at this invention. They asked the question “but Why are drones so loud?” The answer is not so simple: constructive interference. When a propeller spins, it has a noise profile. This noise profile is part spinning motor, part propeller’s interaction with air. This profile has peaks and valleys. Add 3 more propellers with identical noise profiles, and the peaks and […]

A Quieter Propeller: Chasing the Unicorn

This may be old news, but let’s look at the toroidal propeller patent from 2020. It is a valiant attempt to make drones more palatable for the general public. The idea came from the “ring wing” design, an airplane with a wing in the shape of a ring. Tests in WW2 were promising, because this design spreads out the vortices normally concentrated at the tips of regular wings. The inventor of this design (interview here: […]

Pusher-Prop Quad Will Save the Ceilings

In the early days of aviation, planes used pusher propellers. A pusher prop is typically behind the wing, and the concept probably came from boating, with the ship’s screws located on the stern to push the vessel through water. It took a few years for aerospace engineers to realize that puller props (mounted on the nose of the airplane) were superior because they spun through clean, not dirty air. The air behind the wing is […]

Improved VTOL Coaxial Blades

The Osprey is a problematic animal. Not the bird, the aircraft. It took many years and 36 lives (to date) to design a tilt-propeller ship that can take off like a helicopter and fly like an airplane. What if there is a better design? King Abdullah of Jordan thinks so. A recently-granted US Patent discloses a VTOL vehicle that can take off like a helicopter and presumably fly like a plane. The design, using coaxial counter-rotating […]

Draganfly Propellers Remove Easily, Folding Drone Ensues

Clockwise prop for the clockwise motor, counterclockwise prop for the counterclockwise motor Patent.

Parrot’s Bebop Prop Patent

Parrot, the French company that gave us the precursor consumer drone, has filed for a patent application on propeller mounting means. I know first-hand the frustration of seeing a prop fly off a spindle in mid-air, where it goes nobody knows, but it’s somewhere in the lawn. The bird in question is the new Parrot Bebop (http://www.parrot.com/ca/products/bebop-drone/) and it is fabulous. This invention at hand offers the following advantages: 1) Weight distribution of the prop […]