feat: 增加组合折叠姿态干涉扫描、力矩实测与结构强度复核数据

src/arm_build.py

@@ -211,17 +211,21 @@ class Joint:
 
     def rear_mount_holes(self, shape, t_plate=8.0, hole_d=2.8, cb_d=5.5, cb_depth=4.0):
         """Cut the 4x rear mounting bolt holes into a proximal link body.
-        Matches the 4x tapped holes on the motor rear metal endplate:
-        (±17.55, ±20.46) on the rear face at motor-local z = 0.
+        Matches the 4x M3 tapped radial slots on the motor rear endplate
+        (电机.STEP 实测)：BCD55、相位 39.9°+90k，槽宽 2.5、径向可调约 ±1.25mm。
+        旧版误用 35.1x40.9 矩形孔距：对角两颗偏出螺纹槽 ~4.7mm 无处咬合
+        （2026-10-02 用户指出"螺钉没有对齐"，按 STEP 实测槽位修正）。
         """
         cuts = []
-        for sx in (-17.55, 17.55):
-            for sy in (-20.46, 20.46):
-                h = cyl(hole_d / 2.0, -t_plate - 1.0, 3.0, sx, sy)
-                cuts.append(self.L(h))
-                if cb_d > 0 and cb_depth > 0:
-                    cb = cyl(cb_d / 2.0, -t_plate - 1.0, -t_plate + cb_depth, sx, sy)
-                    cuts.append(self.L(cb))
+        for k in range(4):
+            a = math.radians(39.9 + 90.0 * k)
+            sx = 27.5 * math.cos(a)
+            sy = 27.5 * math.sin(a)
+            h = cyl(hole_d / 2.0, -t_plate - 1.0, 3.0, sx, sy)
+            cuts.append(self.L(h))
+            if cb_d > 0 and cb_depth > 0:
+                cb = cyl(cb_d / 2.0, -t_plate - 1.0, -t_plate + cb_depth, sx, sy)
+                cuts.append(self.L(cb))
         return shape.cut(*cuts)
 
     def front_collar_pocket(self, shape, r_bore=30.25, z0=50.0, z1=56.5):