It sounds like the name of the 1970s heavy metal rock band…but that is Twisted Sister, without the “s”. This one is the name given to Theo Geerinck’s IPP37 Exchange Puzzle. The goal is to form a symmetric shape, two to be precise. The puzzle is made of wood and consists of just two pieces of 3D polyominoes. One piece comprises of two trominos glued together, with a total of 6 cubic units. The second is also 6 cubic units, but shaped differently; a domino glued to a tetromino.
Designed by Laszlo Molnar, the puzzle is made out of Cherry (I have one of Laszlo’s earlier puzzlers, the very nice L-I-Vator Cube). The puzzle comes with not one but two solutions. Unlike the increasingly popular 2D form-a-symmetric-shape type puzzles such as the award winning Symmetrick and others like 3 Pentagons which are slowly catching on with a number of designers including myself, Twisted Sisters here requires the solutions to be in 3D symmetric shapes. This ups the challenge ante quite a bit, but not to say 2D symmetrical puzzles are easy to begin with. It depends on the number of pieces and the design.
As you can see from the photo, the pieces look very similar and in the early stages I found myself placing the pieces together in all the different ways I can think of…while each attempt yielded a sort of symmetrical solution, it turned out not to be. Finally I found one which I thought was most likely a right solution and promptly shot a Facebook message to Theo with a photo to ask him to confirm if I had indeed gotten it correct. I was very happy to hear from him that I found one of the two correct solutions. Apologies I can’t show the solutions here so as not to create any spoilers. I didn’t continue with my search for the second over nearly two weeks (while away on vacation) and when I got back to the puzzle again and found what I thought could be the second correct solution, off another message to Theo for confirmation. He has yet to reply given it’s Christmas day today and he’s probably caught up in the festivities. But I do hope my second solution is correct.