CAM-POST NURBS fitting module allows manufacturers to machine smoother, more accurate parts in significantly less time. Interfacing with CNC controllers supporting NURBS output formats, CAM-POST NURBS fitting is capable of defining continuous curve segments with one-quarter program data as compared to traditional linear programming.

Subsequent data reduction translates into feed-rates that are up to four times faster than conventional machining methods. NURBS fitting saves time, preserves tools, reduces machine wear and produces better parts.


Feature / Benefits Highlights

  • Higher feed-rates: Larger interpolation blocks increase feed-rates for faster machining.
  • Greater machining accuracy: Arc tolerances are significantly reduced; thereby creating more accurate parts without increasing program size.
  • Smoother surfaces: Traditional point-to-point machining creates feed “stutter” as the tool changes direction after each individual cut. NURBS fitting eliminates this problem by defining the entire curve as one continuous smooth cut.
  • Compatible with all major CAD / CAM / PLM systems: CAM-POST NURBS fitting is a CAD / CAM system independent solution that can be configured for multiple CAD / CAM / PLM systems.

CAM-POST NURBS fitting supports the following formats:

  • Dual Curve NURBS – supported by CATIA
  • Bezier – supported by Heidenhain controls
  • NURBS – supported by Fanuc and SIEMENS controls
  • Polynomial – supported by Philips and SIEMENS controls
  • Spline – supported by NUM and Fanuc controls

CAM-POST Tangential Arc Fitting

CAM-POST Tangential Arc fitting module improves part finish, significantly reduces tape size and prolongs machine tool life. Arc fitting enables users to increase the feed-rate of NC machines and improve cutting accuracy by replacing point-to-point tool paths with arcs. Since one arc represents curved surfaces more accurately than many linear points, arc fitting reduces NC tape file length by up to 90% while improving overall machining tolerances.

Tangential arc fitting takes this process a step further by ensuring that the arcs fit together so tightly that the NC machine “sees” one continuous tool path resulting precisely machined parts. Smoother tool paths also helps to extend the life of NC machines and cutting tools.

Benefits of Arc fitting as compared to Linear Interpolation

  • Shorter NC tape files: Arc fitting can reduce NC tape files to as little as one-tenth the size of files generated using Linear Interpolation.
  • Smoother, more accurate tool paths: Fitting arcs to the tool path will eliminate almost all the chordal deviation caused by the straight-line approximation of the original surface, resulting in smoother, more accurate tool paths.
  • Higher feed-rates: Larger interpolation blocks allow users to increase feed-rates while virtually eliminating data starvation and stutter step.
  • Compatible with all major CAD / CAM / PLM systems: CAM-POST Arc fitting is a CAD / CAM system independent solution that can be configured for multiple CAD / CAM / PLM systems.

Benefits of Tangential Arc fitting as compared to standard Arc Fitting

  • Greater machining accuracy: Tangential arc fitting provides a better “fit” between arcs for smoother tool paths.
  • Extends NC machine tool life: Smoother tool paths put less strain on machine tools resulting in extended tool life.

Arc Fitting

The average cut method will produce slightly flatter arcs than the overcut method. In either case, arcs will never deviate by more than the allowable tolerance from the original point-to-point motions (P1, P2, P3) being replaced.
Both the starting and ending points of the circle are always points, which exist in the CL file.