Changeset 5700

Timestamp:

10/21/09 22:11:17 (4 years ago)

Author:

werner

Message:

• README: explained what all this is about
• README, rect/rect.c: described "normalized" format used by "rect"
• zscan/: new utility - a surface scanner

Location:

developers/werner/cncmap

Files:

• README (modified) (2 diffs)
• rect/rect.c (modified) (1 diff)
• zscan (added)
• zscan/Makefile (added)
• zscan/zscan.c (added)

developers/werner/cncmap/README

@@ +1 @@
+When milling a surface, we have the following parameters that depend on
+machine configuration and the piece:
+
+- piece location and orientation: the "lower left" edge of the piece is
+  usually not at the origin. Also, the piece may be slightly rotated.
+
+- z coordinates of the piece's surface: even a nominally level piece
+  can be bent. The machine itself may not be perfectly level. And last
+  but not least, there is a fixed but (initially) unknown offset
+  introduced by the milling bit.
+
+The "cncmap" package provides a set of tools for determining these
+parameters and transforming a 2D plot into an accurate surface
+
 The "cncmap" package consists of the following tools:
 
@@ -5 +19 @@
 
 rect: find a rectangle defined by three corner points and print its corners
-in a normalized form.
+in a normalized form, such that they are three adjacent corners of the
+rectangle, with the first corner between the two others, the second point
+"right" when looking from the first point towards the opposite corner, and
+the third point "left".
+
+zscan: scan the surface of a rectangular area with the contact sensor and
+generate a z map.

developers/werner/cncmap/rect/rect.c

@@ -85 +85 @@
         lr_calc(&z0, &zx, &zy);
 
+        /*
+         * Reorder the points such that "o" becomes the corner, "a" and "b"
+         * define the sides of the rectangle, and the angle from "a" to "b" is
+         * as close to 90 degrees as possible, in a counter-clockwise
+         * direction.
+         *
+         * If no angle can be found that's reasonably close to 90 degrees, we
+         * give up.
+         */
+
         best_angle = 0;
         for (o = 0; o != 9; o += 3) {