diff --git a/src/sand-wedge-data/mygrid.cc b/src/sand-wedge-data/mygrid.cc
index b6001067dd79afc1f74b1265a6223a277be92411..b19d164885a0f495f05d55921abf8c7dbad74998 100644
--- a/src/sand-wedge-data/mygrid.cc
+++ b/src/sand-wedge-data/mygrid.cc
@@ -53,12 +53,19 @@ template <class Grid> GridConstructor<Grid>::GridConstructor() {
   auto const BC = midPoint(B, C);
 
   auto const AAB = midPoint(A, AB);
-  auto const AAC = midPoint(A, AC);
   auto const ABB = midPoint(AB, B);
-  auto const ABC = midPoint(AB, C); // the interiour point
+
+  auto const AAC = midPoint(A, AC);
   auto const ACC = midPoint(AC, C);
 
-  unsigned int const vc = 11;
+  auto const BBC = midPoint(B, BC);
+  auto const BCC = midPoint(BC, C);
+
+  auto const ABAC = midPoint(AB, AC);
+  auto const ABBC = midPoint(AB, BC);
+  auto const ACBC = midPoint(AC, BC);
+
+  unsigned int const vc = 15;
 
 #if MY_DIM == 3
   Dune::FieldMatrix<double, 2 * vc, MY_DIM> vertices;
@@ -73,10 +80,14 @@ template <class Grid> GridConstructor<Grid>::GridConstructor() {
     vertices[k++][i] = ABB[i];
     vertices[k++][i] = B[i];
     vertices[k++][i] = AAC[i];
+    vertices[k++][i] = ABAC[i];
+    vertices[k++][i] = ABBC[i];
+    vertices[k++][i] = BBC[i];
     vertices[k++][i] = AC[i];
-    vertices[k++][i] = ABC[i];
+    vertices[k++][i] = ACBC[i];
     vertices[k++][i] = BC[i];
     vertices[k++][i] = ACC[i];
+    vertices[k++][i] = BCC[i];
     vertices[k++][i] = C[i];
     assert(k == vc);
 #if MY_DIM == 3
@@ -86,10 +97,14 @@ template <class Grid> GridConstructor<Grid>::GridConstructor() {
     vertices[k++][i] = ABB[i];
     vertices[k++][i] = B[i];
     vertices[k++][i] = AAC[i];
+    vertices[k++][i] = ABAC[i];
+    vertices[k++][i] = ABBC[i];
+    vertices[k++][i] = BBC[i];
     vertices[k++][i] = AC[i];
-    vertices[k++][i] = ABC[i];
+    vertices[k++][i] = ACBC[i];
     vertices[k++][i] = BC[i];
     vertices[k++][i] = ACC[i];
+    vertices[k++][i] = BCC[i];
     vertices[k++][i] = C[i];
     assert(k == 2 * vc);
 #endif
@@ -117,16 +132,28 @@ template <class Grid> GridConstructor<Grid>::GridConstructor() {
 #else
   SimplexManager sm;
 #endif
-  sm.addFromVerticesFBB(1, 5, 0);
-  sm.addFromVerticesFBB(1, 6, 5);
-  sm.addFromVerticesFBB(2, 6, 1);
+  // bottom row
+  sm.addFromVerticesFFB(1, 5, 0);
+  sm.addFromVerticesFFB(2, 6, 1);
+  sm.addFromVerticesFFB(3, 7, 2);
+  sm.addFromVerticesFFB(4, 8, 3);
+
+  sm.addFromVerticesFBB(6, 5, 1);
   sm.addFromVerticesFBB(7, 6, 2);
-  sm.addFromVerticesFBB(7, 2, 3);
-  sm.addFromVerticesFBB(7, 3, 8);
-  sm.addFromVerticesFBB(7, 8, 10);
-  sm.addFromVerticesFBB(7, 10, 9);
-  sm.addFromVerticesFBB(7, 9, 6);
-  sm.addFromVerticesFBB(8, 3, 4);
+  sm.addFromVerticesFBB(8, 7, 3);
+
+  // the wheel
+  sm.addFromVerticesFBB(10, 9, 6);
+  sm.addFromVerticesFBB(10, 12, 9);
+  sm.addFromVerticesFBB(10, 13, 12);
+  sm.addFromVerticesFBB(10, 11, 13);
+  sm.addFromVerticesFBB(10, 7, 11);
+  sm.addFromVerticesFBB(10, 6, 7);
+
+  // the three surrounders
+  sm.addFromVerticesFBB(6, 9, 5);
+  sm.addFromVerticesFBB(11, 7, 8);
+  sm.addFromVerticesFBB(12, 13, 14);
   auto const &simplices = sm.getSimplices();
 
   // sanity-check choices of simplices