11 Twisted Sisters

I'm sharing some decent Symmetry Puzzles. I will try my best to present them to you.

Symmetry Puzzles are still new species, and the sub-category 3D symmetry puzzles are rarely heard of. For a long time I only knew two 3D symmetry puzzles, Fraternal Twins and Twisted Sisters, I had good time playing them and uploaded models I made for both. Later I saw there's a “plus” version of Twisted Sisters. Adding one extra piece, you get way more challenges!

11 Twisted Sisters

Designer: Tzy Hung Chein

Goal: Make symmetrical shapes out of any 2 pcs.

Note 1: This is Twisted Sisters plus one more piece. By adding one piece there are totally 3 pairs to make symmetry, including the original one pair of Twisted Sisters. So we already had 2 solutions from Twisted Sisters.

Note 2: Assembling all 3 pieces to symmetry is never the goal here. Purely out of curiosity I tried, then I lost count…

Note 3: Normally I only upload puzzles that I fully solved to ensure there's no issues whatsoever. A puzzle made of cubes should be fine, but there's an issue: the author didn't reveal how many solutions there are, then how many is “fully solved”?

I assumed there are 11 solutions, as implied by the name. But no matter how hard I try I can only find 9 shapes of symmetry, unless I count this shape as 3 solutions, for it has both rotational symmetry and 2 planes of mirror symmetry:

But I consider myself cheating, or else a simple square shape would be counted as 5 or more solutions for a symmetry puzzle!

I finally give up and upload this puzzle along the original Twisted Sisters. I assure you there are at least 9 solutions. Give it a try, and maybe you will discover the secret of the number 11?

post process

2 pieces are printed in 2 parts to avoid use of support. Snap them together and you are good to go.

What is Symmetry Puzzle

Symmetry Puzzle is somewhat similar to Tangram. But contrary to Tangram which dates back to hundreds of years ago, the first symmetry puzzle occurs just in this century. The goal of a Symmetry Puzzle is to arrange all the pieces to form a symmetrical shape, any shape is accepted as long as it has symmetry. The solution is often bizarre and hard to find, sometimes you don't even know you get the right shape by failing to recognize its symmetry.

I like Symmetry Puzzles, I especially like 3D printing them. Symmetry Puzzles don't require a packing tray or board (which usually consumes more filaments than pieces), and usually consist of only a few pieces, which makes them very efficient to print. Considering relatively long solving time, Symmetry Puzzles definitely worth printing.

• Symmetry Puzzles are hard, the more the pieces the harder the puzzle become. It's common to take a long time to fully solve a 3-Piece Symmetry Puzzle, and even 2 pieces can make a good puzzle.
  • And yes, there's even 1-piece Symmetry Puzzle that is available to print for yourself. Your task is to determine whether that piece has symmetry, and in case it has, explain what symmetry?
• No packing tray not only save filament cost, it also get rid of worry about tolerance. Tolerance is crucial for most other mechanical puzzles, but tolerance varies for everybody. More often than not when I 3D print a puzzle with packing box or tray, it's either too tight that pieces can't fit in or too loose that I thought I solved it but what I found actually can't work if tolerance is right.
  • No tolerance worry also give you freedom to scale a Symmetry Puzzle to any size,  be it last meter saver or big ornament…
• Some Symmetry Puzzles have multiple challenges / solutions, so print once and enjoy multiple aha moments. In this situation, some challenges are often less difficult, while finding all solutions remain a big challenge. These puzzles are suitable for every player of any puzzle skill level.

If you are interested in Symmetry Puzzles, please visit my collection of all Symmetry Puzzles on this site - I wish there are more but that's all I found. If I missed any please let me know.

Happy Printing & Happy Puzzling Forever!