High Speed Cutting (HSC)

High-Speed Cutting of Large Naval Propellers: Overcoming Challenges with Parallelkinematic-Modules

Current Challenges in High-Speed Cutting of Large Naval Propellers

Machining large naval propellers presents several challenges. The workspace requirements for such huge components demand advanced machinery capable of fast, reliable and precise machining. Key concerns include:

• Machining Time: High chip removal rates are crucial to meet production deadlines.
• Surface Finish: A high-quality surface finish is crucial for the optimal performance of a propeller. Achieving excellent surface quality during the machining process can significantly reduce operational costs by minimizing the need for additional refining steps, such as extended polishing time.

How Parallelkinematic-Modules (PKM) Excel in High-Speed Cutting of Large Cast Parts

The PKM has proven its capability in high-speed cutting, thanks to its unique features:

• Fast and Accurate Machining: The combination of a rigid and lightweight structure ensures consistent performance even at high feeds, lowering machining time and enhancing reliability.
• Large Workspace: Designed to accommodate massive components, the PKM provides ample space for large components.
• Low footprint: The design minimizes the initial investment in foundations and offers flexibility to adapt to existing facilities. Additionally, its lightweight modular structure results in significantly lower energy consumption compared to traditional solutions.
• Single Position Fixturing: The reach of the machine in combination of the large work volume allows machining one complete side of the propeller without refixturing.

Achieving Extraordinary Surface Finishing with Parallelkinematic-Modules

The PKM employs advanced techniques to ensure exceptional surface finishes:

• Process Simulation: Precise path and tool planning by enhanced digital twin.
• 5-Axis Movement: The PKMs capability to move free of singularities around the propeller ensures a constant contour accuracy.
• Rapid Tool Reorientation: 5 times faster tool reorientation due to the high jerk and parallel kinematics.
• Calibration and Compensation: Excels the accuracy of the machine and compensates for external influences. 

Klaus Saffian – Production Manager at MMG

“As a manufacturer of large naval propeller blades, we faced numerous challenges with the costs of the high-speed cutting of our large components.
Thus, we tested the SigmaTau ST 3000 Robot and are extremely impressed with its performance. The ST 3000 handles cast parts of varying sizes with remarkable efficiency, and the competitive machining times help us meet our production demands. The exceptional surface finish reduces later polishing steps, making our process faster and more cost-effective.”

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General information on metal processing

Precise
High contour accuracy and high repeatability.

Fast
Spindle speed up to 80.000rpm, feed speed up to 50m/min.
Fast tool reorientation due to the high jerk and parallel kinematics.

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