Calibration and lens correction

.cor correction files

An F-theta lens distorts the field; the distortion is compensated by a correction table in a .cor file (the EzCad/SeaCAD format). The file is attached in Hardware Settings → Field → Correction File and is part of the lens profile. Three ways to get a .cor:

  1. A ready EzCad file — pick an existing .cor with the browse button.
  2. Import the whole EzCad configuration — the “Import from EzCad…” button reads markcfg7 from a working EzCad machine: field, galvo corrections, delays; if the configuration references a .cor, the file is copied and attached automatically.
  3. Create your own — the lens calibration wizard (below).

The lens calibration wizard

Four steps:

  1. Mark the calibration grid — the machine burns a grid of crosses without correction (5×5, 9×9, or 13×13), with an explicit warning before firing. The step can be skipped if the grid is already marked.
  2. Enter deviations — the measured deviation of each cross in mm; the corners and edges matter most, inner points can stay zero.
  3. Review the correction — an arrow visualization plus a summary of the maximum and RMS deviation.
  4. Save the .cor — with options to “apply to hardware settings” right away and to “mark a verification grid” already with the correction.

BiDir calibration

For the raster scan: the BiDir Offset Calibration dialog (the “Calibrate BiDir…” button in the engrave panel) — one control with fine adjustment until the even and odd scan lines align perfectly. The value is stored on the selected bitmap object.

Test fire

The Test Fire dialog (Hardware Settings → Laser): a controlled pulse into the field center with the chosen frequency, power, pulse width (MOPA), and shot duration; a confirmation before activating the laser, “Laser ON” / “STOP” buttons, and a countdown.

Material Test — the test matrix generator

The Material Test flyout generates a grid of test cells on the canvas: rows sweep one parameter, columns another. Power, speed, frequency, pulse width, and hatch spacing can be varied; the default is speed by rows, power by columns, an 11×11 grid. Cell size and spacing, value labels, a border, and hatch fill are configurable. Burn the matrix with one MARK, pick the best cell, and transfer its mode into a pen (the pen preset library helps build up a per-material base).

Machine verification status

Test fire is machine-confirmed and used in hardware sessions. The lens calibration wizard, BiDir calibration, and Material Test are fully implemented; their systematic verification on the machine is still in progress.