diff --git a/tools/adaptive-isogrid/src/nx/extract_sandbox.py b/tools/adaptive-isogrid/src/nx/extract_sandbox.py
index 2f76d2bf..b4fd907f 100644
--- a/tools/adaptive-isogrid/src/nx/extract_sandbox.py
+++ b/tools/adaptive-isogrid/src/nx/extract_sandbox.py
@@ -169,42 +169,41 @@ def _sample_edge_polyline(edge: Any, chord_tol_mm: float, lister: Any = None) ->
         f"len={length:.3f} tol={tol:.3f} n_pts={n_pts}"
     )
 
-    # 1) Primary: UF_EVAL sampling
+    # 1) Primary: UF_MODL_ask_curve_props — normalized parameter 0..1
     try:
         import NXOpen
         import NXOpen.UF
 
         uf = NXOpen.UF.UFSession.GetUFSession()
-        evaluator = uf.Eval.Initialize2(edge.Tag)
-        limits = uf.Eval.AskLimits(evaluator)
-        t0, t1 = float(limits[0]), float(limits[1])
 
         pts: List[Point3D] = []
         parse_failures = 0
         try:
             for i in range(n_pts + 1):
-                t = t0 + (t1 - t0) * (i / n_pts)
-                result = uf.Eval.Evaluate(evaluator, 0, t)
-                p = _parse_eval_point(result)
-                if p is None:
+                param = float(i) / float(n_pts)  # 0.0 to 1.0
+                # AskCurveProps returns: (point[3], tangent[3], normal[3], binormal[3], torsion, radius_of_curvature)
+                result = uf.Modl.AskCurveProps(edge.Tag, param)
+                # result[0] is the point array [x, y, z]
+                if isinstance(result, (list, tuple)) and len(result) >= 1:
+                    pt_data = result[0]
+                    if isinstance(pt_data, (list, tuple)) and len(pt_data) >= 3:
+                        pts.append((float(pt_data[0]), float(pt_data[1]), float(pt_data[2])))
+                    elif hasattr(pt_data, '__len__') and len(pt_data) >= 3:
+                        pts.append((float(pt_data[0]), float(pt_data[1]), float(pt_data[2])))
+                    else:
+                        parse_failures += 1
+                else:
                     parse_failures += 1
-                    if parse_failures <= 3:
-                        _log(f"[edge] UF_EVAL parse miss at t={t:.6g}, raw={repr(result)}")
-                    continue
-                pts.append(p)
         finally:
-            try:
-                uf.Eval.Free(evaluator)
-            except Exception:
-                pass
+            pass
 
         if len(pts) >= 2:
-            _log(f"[edge] sampled via UF_EVAL ({len(pts)} pts)")
+            _log(f"[edge] sampled via UF_MODL ({len(pts)} pts, {parse_failures} failures)")
             return pts
 
-        _log(f"[edge] UF_EVAL insufficient points ({len(pts)}), falling back")
+        _log(f"[edge] UF_MODL insufficient points ({len(pts)}), falling back")
     except Exception as exc:
-        _log(f"[edge] UF_EVAL failed: {exc}")
+        _log(f"[edge] UF_MODL failed: {exc}")
 
     # 2) Fallback: IBaseCurve.Evaluate (signature differs by NX versions)
     try: