The 3D printer may be nothing more than a tool, but it’s a tool which allows for the creation of complex objects that gives researchers, scientists, and artists a way to realize their vision of the future without resorting to painstakingly slow methods of construction.
It’s the speed at which such creators can design, iterate, and build out their ideas which has led to some amazing advances. Take this vehicle made by James Paulos, one of Professor Mark Yim’s students at the University of Pennsylvania Modlab, for example.
A traditional coaxial micro helicopter uses a large propeller motor, and in conjunction with two small servomotors to control thrust, pitch, and roll forces, generates the necessary forces through coordinated control of multiple actuators.
Paulos, seeking to simplify the entire mechanics of such vehicles, 3D printed a novel propeller architecture, one that allows a single motor and rotor to do the same thing a quadcopter can do, but by controlling and modulating the torque applied to one passively hinged, underactuated propeller.
The three part propeller hub was manufactured on an Objet 3D printer from a plastic polymer, and the fixed hub interfaces with the motor shaft using a commercial aluminum mandrel and two custom plastic blade clamps which connect to the central hub along steel wire hinges.
Conventional UAVs present some serious design challenges and normally require a “swashplate” which means an increase in mass, size, and cost. With four actuators – two big rotor motors, two swashplate servo motors, and a complex linkage assembly – the normal setup is a complicated system indeed.
Paulos says this new rotor system provides “significant system simplifications” while it manages to retain all the advantages of “cyclic control” of current UAV setups.
In Paulos’ system, the main motor directly drives a propeller hub which is itself connected to propeller blades by two inclined, 3D printed hinges. The hinge geometry creates what the designer calls “lead-and-lag oscillations to a change in blade pitch,” and instead of simply driving the motor with a steady torque, a sinusoidal component in phase with the rotation of the rotor can induce a “cyclic pitch variation” which determines the magnitude and direction of the vehicle.
“We can attain this motion directly from a passive dynamic response of the propeller itself,” Paulos says. “For such a propeller the mean applied torque sets the rotational speed and thrust, and an applied oscillatory torque induces the desired cyclic oscillation in blade pitch. Conceptually, this ‘positive’ rotor responds to an impulsive torque on the hub by flexing backwards and exposing increased blade pitch.”
What it means is that the design allows for new types of conventionally-capable micro air vehicles which require just two motors for practical control. Contrast that setup with conventional designs which require many servos and linkages, and the advantages become clear in their simplicity.
Do you think this new rotor and blade design for a UAV represents a workable step forward? Have you worked on UAVs which use 3D printed parts to make them function? Please weigh in with your knowledge or comments in the 3D Printed UAV forum thread on 3DPB.com.
You May Also Like
Researchers Increase Strength of FDM 3D Printed Parts for UAV Applications
A collaborative team of researchers from Kingston University, the University of Liverpool, and Khalifa University of Science and Technology recently published a paper, titled “Additive Manufactured Sandwich Composite/ABS Parts for Unmanned...
Titomic Shares News About 3D Printing Executives and $1.8 Million MoU to Make 3D Printed Soldier Systems
Australian metal 3D printing company Titomic, known for its innovative Titomic Kinetic Fusion (TKF) process, has plenty of big news to share this week. First, CEO Gilbert Michaca, who was responsible...
Examining the Effectiveness of 3D Printing for Drone Construction (MALE UAVs)
Drones are becoming more and more a part of modern life, being used for everything from military applications to delivering pizza, not to mention the growing number of hobbyists using them...
3D Printed Drones and the UAS Integration Pilot Program
Other nations have been more aggressive than the United States regarding drone testing. To accelerate the development of a robust US market, drone operators need to have approved spaces to...