Lock Nut

Designed by Stewart Coffin (design number 105)
Sold in 2006 by Cubic Dissection (www.cubicdissection.com)
(left Bocote / right Cocobola, both 3.25 inches)

Can be solved in two ways using the same pieces; the left above is solved using coordinate motion (all pieces moving together at the same time), and the right above is solved by halving two halves that slide together. The hardest part is trying to visualize what it should look like together once it is apart. Here is what the two solutions look like when starting to come apart: