KENNAMETAL develops lightweight 3D printed stator boring tools for electric vehicles

Kennametal, a tool and industrial material supplier in Pennsylvania, has developed 3D printed stator hole tools in response to the growing needs of automotive customers. This tool is specifically designed for machining parts on hybrid and electric vehicles, and is specially developed for electric vehicle manufacturers looking for lightweight tools. Electric vehicle parts are usually processed on smaller, low-horsepower cnc machining centers, which require lighter weight tooling solutions compared to standard automotive practices.
Kennametal used 3D Printing to create two stator boring tools, which are the fixed part of the rotating equipment on the processing system, and both weigh less than half of the traditionally manufactured similar tools. The main hole that accommodates the motor stator has a diameter of about 250 mm (9.84 inches), a length of about 400 mm (15.74 inches), and a smaller bearing hole at the bottom. Supervisor Harald Bruetting explained. “When manufactured using traditional methods, this type of reamer weighs more than 25 kilograms (55 pounds), which is too heavy for existing machine tools or the work of operators.”

 Equipped with RIQ reamer and The 3D printed stator hole of the KM4X adapter. The picture comes from Kennametal.
Kennametal and additive manufacturing Kennametal was founded in 1938 and is headquartered in Pittsburgh, dedicated to the development of various metal mold products and materials. For example, the company provides blades, disks, skins, fuel control systems and landing gear products for the aerospace industry. It also developed many lathes and fixtures for the machining industry, and provided tools for customers in the automotive industry. The company’s 3D Printing department is called Kennametal Additive Manufacturing, which provides metal powders, optimization and prototyping, and mass production services for additively manufactured parts. The parts are produced using Kennametal’s internal adhesive jet and laser powder bed 3D printing technology. Its internal 3D printers include the X1 25PRO metal adhesive jet system from ExOne, a leading industrial 3D printer provider. Kennametal and the Swedish engineering group Sandvik were appointed by ExOne as a beta tester for 3D printers in May 2019.

Use 3D printing to develop lightweight automotive tools
In order to meet the needs of electric vehicle customers for the stator holes of lightweight Cnc Machine tools, the solution engineering team of Bruetting and Kennametal referred to it as an additive manufacturing solution. Two iterations of the tool were made using metal powder bed 3D printing. The first equipped carbon fiber tube weighs 9.5 kg (20.9 lb), and the other equipped with a 3D printed metal tube weighs 10.7 kg (23.6 lb). Both meet the lightweight requirements of the tool, and the weight is less than half of the standard stator hole, which is 25 kg.  3D printed stator hole with carbon fiber tube. The picture comes from Kennametal.
These tools are also designed with Kennametal’s technology to meet the accuracy, roundness, strength and surface finish requirements of standard stator hole settings. The company equipped it with RIQ reaming inserts for high-precision finishing, and equipped it with KM4X spindle adapters for maximum rigidity. Both tools also have internal 3D printed cooling channels designed to help increase their productivity and service life.