deploy.

App/wwwroot/HiAPI-docsite/technique/measurement/smart-holder-training.html

@@ -95,6 +95,10 @@
 <li>T2 Drill bit, diameter unrestricted</li>
 </ul>
 <p>Click to download <a href="smart-holder-training-img/train.nc">NC code</a>.</p>
+<div class="IMPORTANT">
+<h5>Important</h5>
+<p><strong>What this set determines, and what it does not.</strong> Both <a href="#shape-ii">Shape II</a> passes run T1, so the milling passes span two feeds per tooth — 0.1 and 0.05 — at a single helix angle. That is a spread in the right variable, and a narrow one: it works on the slope–intercept collinearity between the shear and the ploughing coefficients. Nothing in the set works on the other degeneracy, the bending-moment plane null: one combination of the edge and normal shear coefficients stays unobservable, and a set of symmetric four-flute passes carries no cutter phase of its own. Which way the run then fails depends on the channels measured — with the axial torque channel present (<code>IsMzEnabled</code>, see <a class="xref" href="../../workflows/force-training.html">Force Training</a>) the fit converges and reports a high correlation over shear values orders of magnitude too large; without it the fit collapses rather than degrading. Repeating <a href="#shape-ii">Shape II</a> with an end mill of a clearly different helix angle removes the plane null, but does not on its own make the set determined — a wider chip-load range across the passes is the other half. See <a href="training-cut-set-design.html">Designing a Training Cut Set</a>.</p>
+</div>
 <div class="NOTE">
 <h5>Note</h5>
 <p><strong>Adjusting Machining Method</strong></p>

App/wwwroot/HiAPI-docsite/technique/measurement/training-cut-set-design.html

@@ -136,9 +136,23 @@ not by the magnitude of any one coefficient.</p>
 </div>
 <h2 id="flute-count-is-not-a-lever">Flute Count Is Not a Lever</h2>
 <p>Adding more passes with the same symmetric multi-flute cutter buys nothing, at any feed. That
-sample subspace is degenerate, and more of it stays degenerate: a set made only of symmetric
-four-flute passes cannot derive its own cutter phase, and the fit collapses rather than degrading.
-What buys identifiability is spread — in helix angle, and in feed per tooth.</p>
+sample subspace is degenerate, and more of it stays degenerate. Evenly spaced flutes also cancel
+the rotation-averaged transverse moment a run derives its own cutter phase from, so a set made only
+of symmetric passes carries no phase reference of its own. Which way it then fails depends on the
+channels measured: with the axial torque channel present the fit still converges and reports a high
+correlation over shear coefficients orders of magnitude too large; without it the fit collapses
+rather than degrading. Neither outcome is usable, and adding passes repairs neither. What buys
+identifiability is spread — in helix angle, and in feed per tooth.</p>
+<p>Supplying the phase from outside removes that half of the problem and nothing else.
+<a class="xref" href="../../api/Hi.MillingForces.Training.MillingTraining.html#Hi_MillingForces_Training_MillingTraining_EnableCwePhasePairing">EnableCwePhasePairing</a> <small>(API)</small> reads
+each step's phase from the engagement blocks instead of bootstrapping it from the samples, for
+one-flute and symmetric two-flute cutters in light radial side cuts; outside those preconditions the
+training falls back to the bootstrapped path with a warning, so a four-flute set is not rescued by
+it. The null a single helix angle leaves is untouched either way.</p>
+<p>The shipped smart-holder cut set has exactly this shape: its milling passes are one symmetric
+four-flute end mill at two feeds, so the set is spread in feed per tooth alone and does not
+determine its own edge and normal shear values — see
+<a href="smart-holder-training.html">Smart Holder Training</a>.</p>
 <p>Symmetric off-the-shelf cutters are nonetheless sufficient. Custom single-flute grinding is not
 required for either fix; a pair of stock two-flute cutters ground at different helix angles carries
 the same identifiability, and is what a shop can actually obtain.</p>