Tuesday, 1 December 2015

Pinned Wedge Key Puzzle

A rather long name but here's a fun (but not too difficult) puzzle I solved over the weekend. The Pinned Wedge Key Puzzle (PWKP) was Keith Winegar's IPP35 Exchange Puzzle to me in Ottawa, Canada this past August.

When I first saw his puzzle, I was reminded of two earlier puzzles with a similar design; Wil Strijbos' 4-Piece metal puzzle, and Hanayama's Cast Spiral. The object is to take apart the 4 pieces and then reassemble. 

Keith has designed a number of wedge key style puzzles in the past but he takes the PWKP design a couple of notches up.

Firstly in terms of construction, finish and quality...very good. The 4 jigsaw looking pieces are very precisely cut and all the outer edges and surfaces are beveled and smoothed. The puzzle is pretty hefty and solid with a size of 8.8cm x 8.8cm x 2.2cm and made of Black Walnut. 

What is different about the PWKP is that its made more difficult with a number of iron set screws inserted into the pieces. Besides the 4 pieces which "wedge" together to lock themselves, the screws serve as double reinforcement locking. The trick is to figure out how remove the screws and un-wedge the 4 pieces.

Another unusual thing is that the puzzle comes with two paper clips and a large thick rubber band. These are the only "tools" that a solver may use to help take apart the PWKP. No other external tools permitted!

It took me about 10 minutes to figure things out and separate the 4 pieces. Putting everything back was just the reverse.

Overall, a moderately challenging but great puzzle. Novices may take quite a while or even much longer, but for experienced puzzlers, it would be a relatively fast and fun solve. The PWKP is not commercially available but some of Keith's other designs and his earlier wedge key puzzle are available from PuzzleMaster.


  1. I agree this is a well-made puzzle and a good size. I found unlocking mine required a very specific technique which didn't seem to work about half the time. After a while I got better, but it was confusing when the same thing didn't always happen.

    The instructions give a different reassembly technique, but I found it easier simply to reverse the disassembly as you did.

    1. George, I think my own way of disassembly (and reassembly) works better (and pretty consistently) than the instructions, which I didn't quite fully understand,

  2. Hi- I was given one of these pinned wedge key puzzles. No paper clips or rubber bands included. Can you please share the solution?

  3. Hi Margie, please email me via my blog email (I do not wish to post any hints or the solution here) and I will forward you the solution.