Simulation wave artifact.

[jcoffland]

Simulating with a conical tool at a resolution slightly less than the step over of a path which scans back and forth can lead to a wave pattern artifact in the cut workpiece.

Example TPL:

rapid({z: 5});
rapid(0, 0);

feed(400);
speed(10000);
tool(1);
cut({z: -6});

var step = 1;
var off = workpiece().offset;
var dim = workpiece().dims;

for (var i = 0; i <= dim.y / step; i++) {
  cut({y: i * step + off.y});
  cut({x: (i % 2) ? 0 : (dim.x + off.x + 5)});
}

rapid({z: 5});

With a 10° 10mm dia. conical tool and 50x50mm workpiece, this produces:

When simulated at 0.9mm grid resolution, just less than the 1mm step over, you get this false wave pattern:

Simulating at 0.2mm yields a much better simulation without the false wave:

The wire views of each simulation show that the waves appear where the simulation grid is offset most from the path.

They don't appear in the 0.2mm simulation because the grid is small enough:

Camotics simulation file for reference:

{
  "units": "metric",
  "resolution-mode": "manual",
  "resolution": 0.9,
  "tools": {
    "1": {
      "units": "metric",
      "shape": "conical",
      "length": 57.150262,
      "diameter": 10,
      "description": ""
    }
  },
  "workpiece": {
    "automatic": false,
    "margin": 5,
    "bounds": {"min": [5, 5, -10], "max": [55, 55, 0]}
  },
  "files": ["wave_artifact.tpl"]
}