The Hyperboloid Burr is a very fun six-piece burr puzzle made from identical hyperboloid pieces, designed by Oskar van Deventer and Naoaki Takashima.
The puzzle has two solutions. The six-piece version is a put-together that assembles and displays well, but if picked up by a single piece falls apart under its own weight. The seven-piece solution is completed with a satisfying "click" and holds together well.
Both assemblies are made possible by machining to very accurate tolerances. A mere 0.03mm variance and the seven-piece version of the puzzle either does not assemble or falls apart!
The pictures container no spoilers, neither the six or seven-piece assembly is shown. This puzzle ships disassembled.
I must admit that i dont own this brass version but was able to obtain a wooden version from a past IPP. You think "its so easy" but then WHERE DOES THE 7TH PIECE GO!?!? Youll be shocked and amazed as the aha moment rocks your socks and youll marvel in delight at the exceptional work of the "Brass Monkey" teams metal work. Highly recommend.