Tuesday 5 January 2016

4 Ducks & A Duckling

4 Ducks & A Duckling

Jerry Loo

Manufacturer & Availability
My prototype and competition copies were 3D printed by Steve Nicholls. John Hache licensed my design for his IPP35 Exchange Puzzle and his version is laser cut 0.5in thick acrylic. You may wish to contact either Steve or John for availability.

Type & Classification
2D Packing

12.5 cm x 12.5 cm x 2cm (John's version is 10cm x 10cm x 1.25cm)

John Hache's IPP35 Exchange Puzzle (made from laser cut acrylic)

Materials & Construction
3D printed using ABS resin

4 Ducks was the second of my two entries for the IPP35 Nob Yoshigahara Puzzle Design Competition at Ottawa, Canada last August. There are 3 challenges for this puzzle:
  • Fit all 4 ducks into the pond (tray)
  • Fit all 4 ducks and the duckling into the pond
  • Fit all 4 ducks into the pond to form a symmetrical shape
WARNING: The link here shows the solutions. Password - duckling
DO NOT click on the link if you do not wish to see it. 

Difficulty Level
The first challenge is very easy, while the second is moderate. The last is pretty hard; there are 144 ways to fit the 4 ducks into the tray but only ONE will form a symmetrical pattern. Based on feedback, most puzzlers can solve the first two challenges quite quickly but take a while to figure out the third.

Prior to designing 4 ducks, I have been toying around with designing puzzles using the triangular format. While there are some instances where the format is suitable for 3D interlocking burr style puzzles, but for 2D packing puzzles, the format enables more thematic shapes and design options (like the 4 ducks here). I think it also generally makes a puzzle using triangular lines somewhat harder, since most of us are used to and always seeing and playing with vertical/horizontal format puzzle designs.


  1. I prefer the acrylic version. The only problem with acrylic is that it breaks easily. I have several acrylic puzzles which have broken when a piece falls off the table. Other than that, it is nice!

    1. Yes George, it seems that the thicker the acrylic is, the easier it breaks

  2. New challenge for this puzzle: create a symmetrical shape with 3 ducks in the pond. Good luck!