Wednesday, November 25, 2020

The Gift That Keeps Giving - The Ottawa Cube

The Ottawa Cube by Ken Irvine
Several years ago, the hosts of the 35th International Puzzle Party indicated that they liked my 4x4x4 interlocking puzzles and asked if I would be interested in designing the Committee gift for IPP35.  This gift is given to each of the hard-working committee volunteers that make the event run smoothly.  Of course, I was honored and immediately said yes.

The development of the IPP35 puzzle was a collaborative effort between several people including the IPP35 hosts, Brett Kuehner and Rob Stegmann, who provided design criteria, reviewed proposed designs, and provided feedback; myself as the designer; world-renowned craftsman Brian Menold from Wood Wonders to make them; and Rob Jones providing support.  The result of this team effort was the Ottawa Cube.

What prompted me to finally write about the Ottawa Cube this week, is the listing of an Ottawa Cube on the Cubicdissection Marketplace.  Only 30 were made and you don’t see them very often.  This particular copy is an unopened spare from IPP35 that has been added to the puzzle auction to support a charity: Community Food Bank of New Jersey.  The winner will not only support those in need but end up with a rare puzzle as well.

Since it would be awkward to describe how wonderfully awesome this puzzle is, I decided to share some of the highlights of the design process:

Round 1 - Something New

The IPP35 hosts approached me 1½ years before the event to design the puzzle.  They were looking for something similar to my 4x4x4 designs and offered the following criteria:

  • It should be a new, unproduced design.
  • It should not be too expensive to make.
  • It should be challenging but not too difficult to solve.

The Reject Series Puzzles
With that guidance, I set about creating 3 new designs and I brought prototypes to IPP34 and the following Rochester Puzzle Picnic (RPP) for the hosts to review.  Each of the designs consisted of a 4x4x4 puzzle built around an initial concept.  These concepts were:

  • An entire 2x2 face pushed in for the first move.
  • A friction move required for the first move.
  • A puzzle consisting of all U-shaped pieces.

After a thorough review by the hosts, they said that’s nice, … , but it’s not what we’re looking for.  They were looking for something more theme related to IPP35 in Ottawa, Canada.

I dubbed the 3 designs - The Reject Series, and they are now even rarer than the Ottawa Cube.  There are only 3 complete sets and I have one of them.

Round 2 - Something Themed

The Ottawa Cube in BurrTools
Armed with a pocket full of rejection, I thought about how I would approach a themed puzzle.  I pretty quickly decided on a cube with letters on the side with the following criteria:

  • The cube would have to be 5x5x5.  A 4x4x4 cube was just too small and anything larger would be too expensive.
  • All the characters used would be on the face of the puzzle and not hidden inside.
  • It would be done in two colors with red for the foreground and white for the background to match the Canadian flag.
  • Each piece would be a single color and not a combination of the two colors.  Yes, sometimes I like to make things unnecessarily complex for myself.  However, without this restriction, you could take any 5x5x5 puzzle and make it look the way you want and I felt that it would lose the quality of what makes it unique if that was done.

I worked up an initial prototype using live cubes and sent pictures to the hosts for an initial assessment to verify that I was on the right track.  I was glad to get a response back that it looked worth pursuing.

Round 3 - Something More Complex

The Ottawa Cube Pieces
Unfortunately, there was no way to lay out the letters on the face where the adjacent edges matched color.  To solve this dilemma, I had to up my game and cut the corner cubes at a 45-degree angle to get a different color on each face.  Of course, this was no longer a cubic dissection and I realized that I had probably just shot the expense criteria to hell.  

Did I mention that I imposed a restriction where each of these different color cube halves can’t be part of the same piece?  Needless to say, it was a challenge to develop an interlocking puzzle with purely colored pieces.

I created a BurrTools file of the new design where each cube in the puzzle was represented by a 3x3x3 set of cubes to allow me to cut them in half at an angle.  BurrTools was able to successfully solve the puzzle, which is always welcome feedback.

With a bit of trepidation, I sent the BurrTools file out to the team for review.  I was particularly worried about what Brian would have to say about all those 45-degree angle cuts.  As an amateur wood dabbler, it looked insurmountable to me.  

Round 4 - Final Product

The Ottawa Cube Backside
With the design process complete, Brian Menold took over the development of the Ottawa Cube. Aside from some recommended changes to improve the structural reliability of the pieces from Brett and Rob’s review of an initial prototype, it was good to go.  Rob also suggested the name: The Ottawa Cube.

The final product is a gorgeous cube with the letters for IPP35 on 5 of the 6 faces.  It’s made with Redheart and Maple to represent the red and white colors of the Canadian flag.  It’s also fairly big and heavy at slightly over 3” per side.

When I first saw the Ottawa Cube at IPP35, I was amazed on how beautiful they looked and how smoothly they moved.  Brian did an amazing job with the 45-degree angled pieces and I was impressed on how well everything came together.

I’m sure that Brian has his own story to tell about unrealistic designers and constraints.  After everything was done and I chatted with Brian about the project, I thought I heard him mumble something under his breath like “neber eggen”.

I’m glad to have been part of The Ottawa Cube team and thoroughly enjoyed working with the team.  I hope that others will be interested in acquiring a copy and helping support the Community Food Bank of New Jersey by bidding generously on the Cubicdissection Marketplace Ottawa Cube listing this week.

The Ottawa Cube Box Label


  1. Thanks for sharing the process of this design. I think it's fascinating how other people come up with their designs.

    1. This one was a nice collaboration for a specific event. I was happy to be a part of it and very satisfied with the result. Perhaps a TIC for a future gift ...

  2. This was among my top 3 for 2015. Thanks again, Ken. -Tyler.

    1. That's great to hear Tyler! You never really hear anything about it since there were only 30 made.