diff --git a/rocolib/builders/boat/mounts/ServoMountWithArmsBuilder.py b/rocolib/builders/boat/mounts/BottomServoMountBuilder.py
similarity index 82%
rename from rocolib/builders/boat/mounts/ServoMountWithArmsBuilder.py
rename to rocolib/builders/boat/mounts/BottomServoMountBuilder.py
index 52435286d7d81b7b18b7177679eb5e4a8160a9d7..1ffa889af3486d42c54b218e0c49fe224f98b085 100644
--- a/rocolib/builders/boat/mounts/ServoMountWithArmsBuilder.py
+++ b/rocolib/builders/boat/mounts/BottomServoMountBuilder.py
@@ -9,21 +9,21 @@ c.addParameter("width", 90, parameterType="length") # = boat depth
 c.addSubcomponent("servoMount", "SideServoMount", inherit="depth")
 
 c.addSubcomponent("leftArmDown", "Rectangle")
-c.addConstConstraint(("leftArmDown", "w"), 24)
+c.addConstraint(("leftArmDown", "w"), "servoMount.depth")
 c.addConstraint(("leftArmDown", "l"), "depth", "x-3") #DEPTH OF BOAT - 3 for the tab
 
 c.addSubcomponent("leftArmAcross", "Rectangle")
-c.addConstConstraint(("leftArmAcross", "w"), 24)
+c.addConstConstraint(("leftArmAcross", "w"), "servoMount.depth")
 c.addConstraint(("leftArmAcross", "l"), ("width", "servoMount.depth"), "x[0]/2 - x[1]/2") #DEPTH OF BOAT - 3 for the tab
 
 c.addConnection(("leftArmDown", "r"), ("leftArmAcross", "r"), angle=-90)
 
 c.addSubcomponent("rightArmDown", "Rectangle")
-c.addConstConstraint(("rightArmDown", "w"), 24)
+c.addConstConstraint(("rightArmDown", "w"), "servoMount.depth")
 c.addConstraint(("rightArmDown", "l"), "depth", "x-3") #DEPTH OF BOAT
 
 c.addSubcomponent("rightArmAcross", "Rectangle")
-c.addConstConstraint(("rightArmAcross", "w"), 24)
+c.addConstConstraint(("rightArmAcross", "w"), "servoMount.depth")
 c.addConstraint(("rightArmAcross", "l"), ("width", "servoMount.depth"), "x[0]/2 - x[1]/2") #DEPTH OF BOAT - 3 for the tab
 
 c.addConnection(("rightArmDown", "r"), ("rightArmAcross", "r"), angle=-90)
@@ -34,4 +34,4 @@ c.addConnection(("servoMount", "rightInterface"), ("rightArmAcross", "l"))
 c.inheritInterface("leftArmInterface", ("leftArmDown", "l"))
 c.inheritInterface("rightArmInterface", ("rightArmDown", "l"))
 
-c.toLibrary("ServoMountWithArms")
+c.toLibrary("BottomServoMount")
diff --git a/rocolib/library/ServoMountWithArms.yaml b/rocolib/library/ServoMountWithArms.yaml
index 002b20ea82da0159fbe773c95b97d07877596507..865c3d1a402d37ffda42e350b0ea7718870501c2 100644
--- a/rocolib/library/ServoMountWithArms.yaml
+++ b/rocolib/library/ServoMountWithArms.yaml
@@ -45,7 +45,7 @@ parameters:
     defaultValue: 90
     spec:
       parameterType: length
-source: ../builders/boat/ServoMountWithArmsBuilder.py
+source: ../builders/boat/mounts/ServoMountWithArmsBuilder.py
 subcomponents:
   leftArmAcross:
     classname: Rectangle
@@ -64,7 +64,8 @@ subcomponents:
       l:
         function: x-3
         parameter: depth
-      w: 24
+      w:
+        parameter: servoMount.depth
   rightArmAcross:
     classname: Rectangle
     kwargs: {}