Wednesday, 17 June 2015

Visible Burr

This interlocking burr gave me a real headache! In fact I was "visibly" frustrated trying to assemble the thing after it arrived in pieces....all twenty four of them. More about this later.

The Visible Burr, designed by Bill Cutler is a handsome puzzle. With its size about 13cm x 13cm x 13cm, this thing is relatively large and displays really well. Made by Eric Fuller, the craftsmanship is excellent. All the pieces are precisely cut and  slide smoothly against each other with just the right amount of tolerance. Eric had chosen Canarywood, Purpleheart and Paduak which gives it a contrast of rich colours. 

Now what is so special about the Visible Burr? Well, for one, its a classic and dates back to 1978. It has been made by different puzzle craftsmen since that time. Here's what Bill said about his design...

"I like to design burrs which are difficult to take apart. This requires irregular notches in the pieces, and I usually like to hide these in the interior of the puzzle. With the Visible Burr, I decided to make all of the notches visible to the solver. Solution of this puzzle can thus be done by analyzing the notches, rather then by using trial-and-error."

While it may look extremely complicated, dis-assembly is humanly possible as Kevin Sadler can testify. He has gotten it into pieces and now (still) figuring how to fix it back together; good luck Kevin! On paper its not that difficult being a Level 7 solution with a total of 46 moves. But its apparently a real tough cookie! And I am not so sure about the re-assembly tho'

I thought with the aid of that savior of puzzlers a.k.a Burr Tools, I could get the twenty four pieces backed to the solved state in a jiffy but no such luck. I was in for a rude shock! It is very difficult to assemble even with Burr Tools. The fact that the pieces slide smoothly caused me the biggest problem, I could not get the early six or seven pieces to "stay put" together in my left hand while using my right to handle the assembly. Identification of the pieces is also not easy at all, given there are so many and looking similar (Hint-mark your pieces according to the numbering in Burr Tools; it will save you a lot of hassle later). 

Missed a step and had to back track...with only two pieces left to go

So what did I do?...ha ha, I allowed the pieces to stay outside of my dehumidifier puzzle closet in the open to let the pieces expand a bit so they would be more "sticky" against each other. For once, I was really thankful that Singapore has high humidity, 70-90%. Two days of exposure to the environment and presto... the pieces "held" themselves and I could concentrate on the fixing instead of the grappling. But even with this problem solved, it was still a very tricky task...the movements of many of the pieces are very subtle, tiny even. Miss one and you can get stuck for a while wondering what went wrong. I made it all the way with only two pieces left before I discovered I had overlooked a step (and a piece) and had to back track about 5 moves and start again. 

All in, I think it took me nearly three hours from start to finish. The most difficult assembly I have ever done for a burr, and mind you, this is with guidance of Burr Tools.

The Visible Burr is still available from Eric for US$109, fully assembled. Previously you had to top up another US$10 for an assembled puzzle.


  1. Incredible puzzle. I am still daunted by burrs and have no idea how to use burr tools. I'll just enjoy reading about how you accomplished it!

    1. Oh no, I couldn't have done it without Burr Tools! I am very lousy at burrs too!