diff --git a/gantry.py b/gantry.py
index 9a57aab..217c21e 100644
--- a/gantry.py
+++ b/gantry.py
@@ -96,14 +96,19 @@ class Gantry:
             .rect(column_spacing + tube_w, tube_w)
             .extrude(plate_z)
         )
-        self.ball_screw_w = w.transformed(
-            offset=(
-                ballscrew_len / 2 - (-15 - 39 + 25 + 10 - 7 / 2 - 20 / 2) / 2,
-                ballscrew_x_offset,
-                (upper_center + lower_center) / 2,
-            ),
-            rotate=(0, 0, 90),
-        ).transformed(rotate=(0, 90, 0))
+        self.ball_screw_w = (
+            cq.Workplane()
+            .copyWorkplane(w)
+            .transformed(
+                offset=(
+                    ballscrew_len / 2 - (-15 - 39 + 25 + 10 - 7 / 2 - 20 / 2) / 2,
+                    ballscrew_x_offset,
+                    (upper_center + lower_center) / 2,
+                ),
+                rotate=(0, 0, 90),
+            )
+            .transformed(rotate=(0, 90, 0))
+        )
         self.ball_screw_model = SFU1204(self.ball_screw_w, ballscrew_len)
         self.floating_mount_w = self.ball_screw_w.transformed(
             offset=(0, ballscrew_len + (-10 + 7 / 2 + 20 / 2), 0), rotate=(-90, 0, 0)
@@ -372,7 +377,7 @@ class Carriage:
             .copyWorkplane(rbolster_w)
             .rect(bolster_w, carriage_h)
             .extrude(bolster_z)
-            .copyWorkplane(lbolster_w.transformed(rotate=(0, 180, 0)))
+            .copyWorkplane(rbolster_w.transformed(rotate=(0, 180, 0)))
             .pushPoints(points)
             .hole(3)
         )
@@ -399,6 +404,27 @@ class Carriage:
             .rect(60, 60)
             .extrude(64)
         )
+        self.x_nut_mount = gantry.ball_screw_model.nutHoles(
+            self.x_nut_mount, x + carriage_w / 2
+        )
+        self.x_nut_mount = self.x_nut_mount.copyWorkplane(
+            gantry.ball_screw_model.w.transformed(
+                offset=(0, x + carriage_w / 2, 0), rotate=(90, 0, 0)
+            ),
+        ).hole(14)
+
+        def nut_mount_holes(s, forward=True):
+            return (
+                s.copyWorkplane(back)
+                .center(-x - HGR20.L - x_carriage_spacing / 2, -x_rail_spacing / 2)
+                .transformed(rotate=(0 if forward else 180, 0, 0))
+                .rect(44, 44)
+                .vertices()
+                .hole(5)
+            )
+
+        self.x_nut_mount = nut_mount_holes(self.x_nut_mount)
+        self.plate = nut_mount_holes(self.plate, forward=False)
 
         # these are filled in by the carrier
         self.z_nut_mount = None