My Ball In A Cube is similar to my Overlapping Cube puzzle. However it has more combinations and is trickier to solve. There are an additional 12 hidden pieces that need to be positioned and correctly orientated. These pieces correspond to the middle edges on a 5x5x5 though not as straightforward to deal with. They are only properly visible between completed moves (see the photos). All moves are accessed from the exterior cube so you never have to reach in and touch the ball.
As with my Overlapping Cube it has a central block which hinders certain movement. It is difficult to understand the effect of this block on the puzzle without handling it. Many people believe the block stops the puzzle being fully functional. However this is far from true since the block has always existed in the mechanism and does not prevent the full mixing of the puzzle. Removing the block would add functionality though would be a completely pointless exercise since the block is what makes it and my Overlapping Cube unique solving challenges. It's a bit like saying a Skewb is not fully functional since the corners can't turn. Without the block you just have a regular 5x5x5 with a few parts missing. In addition the middle row would be awkward to move and line up.
I am very pleased with the quality and rotational movement is smooth. The cube stickers are from the Eastsheen 4x4x4 it was made from and the ball stickers are made from the same high quality textured material you find on Skewbs. I have found that these Skewb style stickers are much better than normal Rubik's Cube type on curved surfaces.
To construct my Ball In A Cube it was necessary to first construct a Mini 5x5x5 Ball. Once the ball was made I could then use the appropriate parts to construct this puzzle. Everything was done by hand without the use of rapid prototyping.
It is definitely one of my favourites. I made it in 2008.