Two relatives of the plummer cross which people may find interesting
are given here:

The first is called a baseball.

      lL U L
      L U U
      L L L
F F F U U U B R B D B D
L L F U F F R R B D B B
F L F U F U B B B D D D
      R D R
      D D R 
      R R R

I do this one in 50 qtw though I know how to shorten it to 42.

The second is called a cube in a cube.

      L L L
      U U L
      U U L
F L L F F U B B B D D D
F L L F F U B R R B B D
F F F U U U B R R B B D
      R R R
      R D D
      R D D

I do this one in 70 qtw, though I could reduce it to 62.

These configurations both have two minor variants
which leave the essential nature of the configuration the same.
these other patterns are obtained by twisting the FUL AND BDR
corners. Both of these patterns were devised by people at Caltech.

Chris Worrell (ZILCH @MIT-AI)