Khaled's Time Machine was suggested by Khaled Habbab. His idea combines Polo Gear Cube (conceived by Alex Polonsky) and Time Machine (by Li Chung Man).
The creation of the two prototypes was sponsored by Khaled. This first prototype was a miserable failure. The 2x2x2 turning was fine, but the gearing was completely jammed. The second prototypes had two improvements. First of all, the numbered pieces are now well confined in a rails mechanism. Secondly, the numbered pieces are centered around a circle, as was suggested by Khaled. The result is a puzzle that turns much better than Khaled and I could have dreamed.