Amorphology Inc. and Additive Technologies (AddiTec) have joined forces to 3D print large steel strain wave gear flexsplines.
Amorphology is a NASA spinoff company founded from technology developed at the Jet Propulsion Laboratory (JPL) and the California Institute of Technology (Caltech).
Strain wave gears are a compact and zero backlash gearbox used in robotic arms and precision-motion mechanisms. They transmit torque through a geared thin-walled cup, hat, or band, called a flexspline.
The flexspline has precise gear teeth and a flexible wall, a combination of qualities that drives the manufacturing costs of a strain wave gearbox.
Because of their complexity, strain wave gears account for a substantial portion of the cost of a six-degree-of-freedom (6DOF) robotic arm, says Amorphology CTO Dr. Glenn Garrett.
“When you look at machining of flexsplines that are 6 to 8 inches in diameter, the large steel feedstock may be reduced to as little as 10% of its original volume.”
“This is a detriment from both cost and sustainability standpoints, as energy and material are wasted to produce a part which is a shell of the original stock.”
Garrett contends that additive manufacturing offers a more promising alternative as machining costs can be dramatically reduced while allowing for the cost-effective use of high-performance steels.
To showcase this, Amorphology and AddiTec have demonstrated a 6-inch diameter prototype of a strain wave gear flexspline printed in high-performance 17-4 precipitation hardened steel.
According to Amorphology, the prototype was fabricated on a Haas CNC hybrid system running the Meltio Engine. The printed part was later removed from the build-tray and then CNC machined into the precision shape.
The process also allows for flexible and on-time production of a variety of large flexsplines without having to keep many diameters of stock in house.
Image and content: Amorphology via BusinessWire