Contour parallel Roughing

Multiple complex surfaces can be roughed out using an efficient Z-level cutting strategy. With the Contour parallel roughing routine, material is removed at uniform depths, until all the excess material is removed. The toolpath results by default in constant climb milling for good utilization of spindle horsepower. A uniform stock amount can be designated to allow for finishing passes. This function is capable of using bull, ball, and flat cutter geometry, but the flat end tool will usually result in the fastest material removal rates.

Requires selected surfaces to be enabled. Optional selections of stock box and/or multiple nested restriction curves provide precise control of the area to be roughed. In the following example only the surfaces and the stock box are selected.

Select the model to be 3D machined and the Box stock and/or restriction curves. The stock box will control the absolute maximum depth of cut in Z, as well as the extents in X and Y. For best results a stock box is recommended.

NC-3D Milling-Roughing Z-Constant-Contour Parallel

Tool Section

Select the desired tool from the Tool library

Override or modify the Diameter D and E if needed.

Set the tool origin to tool tip or tool radius center

NC-Path Section

Sidestep Distance the maximum distance between the contour offsets that are created to rough out the excess material. Defaults to 45% of flat end tool diameter and 20% of ball end tool diameter.

Interpolation error – the coarseness of the toolpath as it is created from the surface. Set to a relatively large value such as .01 inches when testing the function. Use a value no larger than the stock distance to insure no gouging of the workpiece.

Scallop height - is automatically calculated for a Ball end mill when Sidestep distance is entered. Not really applicable when a flat end cutter is used.

Surfaces Section

Interpolation error – This value determines the coarseness of the surface interpolation. Set to a relatively large value such as .01 inches when testing the function. Use a value no larger than the stock distance to insure no gouging of the workpiece.

Stockdistance – Minimum amount of finish stock to be left after all cutting is completed.

Z-Tooling Section

Z-Height – Set to Zero to rough from the top of the stock box down. Set to a larger value to start the roughing passes from an arbitrarily higher or lower location.

Step Dz – This value determines the depth of cut per pass of the roughing cutter.

The following image shows simulation of Contour parallel roughing. Note that 5 passes to the total depth were created.

The result of the function is an entry in the Job table which can be simulated and from which NC code can be generated.