Updated the CadQuery library.

CadQuery/Libs/cadquery/CQ.py

@@ -298,6 +298,10 @@ class CQ(object):
             For now you can work around by creating a workplane and then offsetting the center
             afterwards.
         """
+        if len(self.objects) > 1:
+            raise ValueError("Workplane cannot be created if more than"
+                             " 1 object is selected.")
+
         obj = self.objects[0]
 
         def _computeXdir(normal):

CadQuery/Libs/cadquery/selectors.py

@@ -291,13 +291,13 @@ class DirectionMinMaxSelector(Selector):
             allow '>(0,0,1)' to work.
 
     """
-    def __init__(self,vector,directionMax=True):
+    def __init__(self, vector, directionMax=True, tolerance=0.0001):
         self.vector = vector
         self.max = max
         self.directionMax = directionMax
+        self.TOLERANCE = tolerance
     def filter(self,objectList):
 
-        #then sort by distance from origin, along direction specified
         def distance(tShape):
             return tShape.Center().dot(self.vector)
             #if tShape.ShapeType == 'Vertex':
@@ -306,10 +306,14 @@ class DirectionMinMaxSelector(Selector):
             #    pnt = tShape.Center()
             #return pnt.dot(self.vector)
 
+        # find out the max/min distance
         if self.directionMax:
-            return [ max(objectList,key=distance) ]
+            d = max(map(distance, objectList))
         else:
-            return [ min(objectList,key=distance) ]
+            d = min(map(distance, objectList))
+
+        # return all objects at the max/min distance (within a tolerance)
+        return filter(lambda o: abs(d - distance(o)) < self.TOLERANCE, objectList)
 
 class BinarySelector(Selector):
     """