diff --git a/extra/fillet-radius.py b/extra/fillet-radius.py
new file mode 100644
index 0000000..a64ba27
--- /dev/null
+++ b/extra/fillet-radius.py
@@ -0,0 +1,70 @@
+import matplotlib.pyplot as plt
+from math import sqrt
+import sys
+
+if __name__ == "__main__":
+    
+    try:
+        stype = sys.argv[1]
+
+    except IndexError:
+        print("python fillet-radius.py [simple|bodyCentered|faceCentered]")
+
+        exit(1)
+
+
+    if stype == "simple":
+        r0 = 1.0
+        
+        C1, C2 = 0.8, 0.5
+        theta1, theta2 = 0.01, 0.28
+        
+        delta = 0.2
+
+    elif stype == "bodyCentered":
+        L = 1.0
+        r0 = L * sqrt(3) / 4
+
+        C1, C2 = 0.3, 0.2
+        theta1, theta2 = 0.01, 0.18
+        
+        delta = 0.02
+
+    elif stype == "faceCentered":
+        L = 1.0
+        r0 = L * sqrt(2) / 4
+
+        C1, C2 = 0.3, 0.2
+        theta1, theta2 = 0.01, 0.13
+
+        delta = 0.012
+
+    else:
+        print("python fillet-radius.py [simple|bodyCentered|faceCentered]")
+
+        exit(1)
+
+
+    Cf = lambda theta: C1 + (C2 - C1) / (theta2 - theta1) * (theta - theta1)
+    fillet = lambda theta: delta - Cf(theta) * (r0 / (1 - theta) - r0) 
+    
+    tocount = lambda num: int(num * 100)
+
+    theta = [ 0.01 * n for n in range(tocount(theta1), tocount(theta2) + 1) ]
+    coeffs = [ Cf(n) for n in theta ]
+    radiuses = [ fillet(n) for n in theta ]
+
+    plt.figure(1)
+    
+    plt.subplot(211)
+    plt.plot(theta, coeffs, "o")
+    plt.grid(True)
+    plt.ylabel("Cf")
+
+    plt.subplot(212)
+    plt.plot(theta, radiuses, "o")
+    plt.grid(True)
+    plt.ylabel("Radius")
+    plt.xlabel("Theta")
+    
+    plt.show()
diff --git a/samples/bodyCentered.py b/samples/bodyCentered.py
index d3dd7a6..0f33c91 100644
--- a/samples/bodyCentered.py
+++ b/samples/bodyCentered.py
@@ -28,10 +28,11 @@ def bodyCenteredCubic(theta = 0.01, fillet = False, direction = [1, 0, 0]):
     yw = xl
     zh = height
 
-    C1, C2 = 0.8, 0.5 #0.8, 0.05
-    theta1, theta2 = 0.01, 0.13
+    C1, C2 = 0.3, 0.2 
+    theta1, theta2 = 0.01, 0.18
     Cf = C1 + (C2 - C1) / (theta2 - theta1) * (theta - theta1)
-    filletradius = 0.05 - Cf * (radius - r0)
+    delta = 0.02
+    filletradius = delta - Cf * (radius - r0)
     
     scale = 100
     oo = geompy.MakeVertex(0, 0, 0)
@@ -178,10 +179,11 @@ def bodyCenteredHexagonalPrism(theta = 0.01, fillet = False, direction = [1, 1,
     point.append((0 + xl, L + yw, L + zh))
     point.append((L / 3 + xl, L / 3 + yw, 4 * L / 3 + zh))
 
-    C1, C2 = 0.8, 0.05
-    theta1, theta2 = 0.01, 0.13
+    C1, C2 = 0.3, 0.2
+    theta1, theta2 = 0.01, 0.18
     Cf = C1 + (C2 - C1) / (theta2 - theta1) * (theta - theta1)
-    filletradius = Cf * (radius - r0)
+    delta = 0.02
+    filletradius = delta - Cf * (radius - r0)
     
     scale = 100
     oo = geompy.MakeVertex(0, 0, 0)
diff --git a/samples/faceCentered.py b/samples/faceCentered.py
index bb32cb4..0a24740 100644
--- a/samples/faceCentered.py
+++ b/samples/faceCentered.py
@@ -28,10 +28,11 @@ def faceCenteredCubic(theta = 0.01, fillet = False, direction = [1, 0, 0]):
     yw = xl
     zh = width
 
-    C1, C2 = 0.8, 0.05
+    C1, C2 = 0.3, 0.2
     theta1, theta2 = 0.01, 0.13
     Cf = C1 + (C2 - C1) / (theta2 - theta1) * (theta - theta1)
-    filletradius = Cf * (radius - r0)
+    delta = 0.012
+    filletradius = delta - Cf * (radius - r0)
     
     scale = 100
     oo = geompy.MakeVertex(0, 0, 0)
@@ -176,10 +177,11 @@ def faceCenteredHexagonalPrism(theta = 0.01, fillet = False, direction = [1, 1,
     point.append((-width + xl, 0 + yw, 0 + zh))
     point.append((-2 * width / 3 + xl, -2 * width / 3 + yw, width / 3 + zh))
 
-    C1, C2 = 0.8, 0.05
+    C1, C2 = 0.3, 0.2
     theta1, theta2 = 0.01, 0.13
     Cf = C1 + (C2 - C1) / (theta2 - theta1) * (theta - theta1)
-    filletradius = Cf * (radius - r0)
+    delta = 0.012
+    filletradius = delta - Cf * (radius - r0)
     
     scale = 100
     oo = geompy.MakeVertex(0, 0, 0)