Non-concentric Arc Toolpath for CNC Milling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Classic parallel offset milling algorithms face issues with tangent discontinuities causing tool load spikes, material removal rate variations, and potential tool failure, and are inefficient, especially in high-speed milling, due to the need for additional tool motion that can increase the toolpath length by up to 200%.
Innovation Solution
The described technology modifies the Voronoi Diagram by adding branches and adjusting edge lengths to create non-concentric arcs in the toolpath, reducing material removal rate and tool load, and improving chip clearance and heat dissipation, while maintaining a negligible increase in toolpath length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If classic parallel offset milling algorithms are used, then the toolpath is simple to generate, but tangent discontinuities cause tool load spikes and material removal rate variations
Solution Approach 1:
The patent transforms the toolpath from piecewise linear segments to continuous circular arcs by changing the geometric parameters. Each arc is defined by a center point, radius, and sweep angle, ensuring tangent continuity. This parameter transformation eliminates discontinuities while maintaining manufacturing simplicity through automated calculation algorithms.
Solution Approach 2:
The patent replaces linear toolpath segments with circular arcs that have continuous tangents. By using curved paths instead of straight lines, the tool load becomes smooth and continuous, eliminating spikes caused by sharp corners or discontinuous segments in traditional offset algorithms.
2Reliability
If additional tool motion is added to smooth material removal rate, then tool load stability improves, but toolpath length increases by up to 200%
Solution Approach 1:
The patent calculates optimal arc parameters (center points, radii, sweep angles) that naturally provide smooth material removal rates without requiring excessive tool motion. By transforming the geometric parameters from linear offsets to circular arcs, the system achieves load stability with minimal additional path length.
Solution Approach 2:
Instead of adding excessive tool motion to ensure smooth material removal, the patent uses precisely calculated circular arcs that provide just enough curvature to maintain tangent continuity. This partial action approach achieves the necessary smoothness without the 200% toolpath length increase of conventional methods.
3Productivity
If high feedrate is used to compensate for longer toolpath, then productivity is maintained, but tool load spikes and heat generation increase
Solution Approach 1:
The patent uses circular arcs with continuous tangents to eliminate tool load spikes. The curved paths ensure smooth material removal rates even at high feedrates, preventing the load variations that would otherwise occur with linear segments. This allows high-speed machining while maintaining tool reliability.
Solution Approach 2:
The patent ensures continuous and smooth material removal throughout the toolpath by using circular arcs. This continuity prevents interruptions or spikes in the cutting action, allowing the tool to operate efficiently at high feedrates without generating excessive heat or load variations that would reduce tool life.
Data Source
AI summary
Technology for milling selected portions of a workpiece by a cutting tool of a numerical control machine is described. The described technology provides methods and apparatuses for milling areas of a part so that more aggressive machining parameters can be used in the toolpath, thereby resulting in reduced machining time and load. The technology creates a series of toolpath contours where arcs in the toolpath contours are non-concentric with arcs in other toolpath contours. The selected portions of the workpiece are milled by moving the cutting tool in accordance with the toolpath.