Thursday, December 20, 2012

3d Printer Brings New Light to Antique Japanese Lantern

Ben Sherwood experimented with the use of modern technologies to help repair this 150 year old Japanese lantern.  It was missing a curved wooden rib like the one in the picture, so we 3D printed a replacement on the SD300.

The 3D printed rib fit the size and curvature of the lantern perfectly, thanks to careful measurements that Ben took prior to building it.  But naturally the modern plastic looked a bit funky among all the wood and paper components of the lantern.

Ben Purdy, a maker colleague, took my CAD data and adapted it to a vector drawing so he could make a replacement rib in acrylic using a laser cutter.

It looked even funkier than the 3D printed rib, but the acrylic rib fit the lamp so neatly that it could have been used to make a perfect repair.

Ben turned up the intensity of the laser and cut another replacement rib from solid wood.

The laser charred the sides of the wooden rib, which makes it a nice match for the original wood in the Japanese lantern.

The laser didn't touch the top edge of the rib, so it's still pale.  But Ben can choose to apply stain and lacquer to make it a perfect match if he chooses.  Although the 3D printer didn't manufacture the final replacement rib, it was a helpful catalyst for completing the project.

It was certainly a fun, satisfying project.  Ben Sherwood shared it in a five-minute standup presentation at Ignite TAO PDX at the Alberta Rose Theater in Portland, which they recorded for posterity...

Thursday, September 27, 2012

Success 3 - Guile in the Box

Partial-spoiler warning: This blogpost does not disclose the solution, but for the sake of discussion it discloses history and design details that could spoil some of the surprises, especially for avid puzzlers.

Guile in the Box was my first-ever entry in the Nob Yoshigihara Puzzle Design competition, another personal landmark.  The challenge is to fit the four pieces into the box and shut the lid.  The four pieces are almost identical--each has an off-center notch, but one piece is a mirror image of the other three.  The box at rear left shows how three pieces (white) nearly fill the box, so the fourth piece is attached to a storage hook on the outside of the box.

Inspiration came from the 4-T Puzzle, an elegant challenge to fit four T-shaped pieces into square openings of two different sizes.  It's trivial to fit the pieces into the larger square, but the smaller one requires an "Aha!" insight.  The 4-T Puzzle is currently sold by ThinkFun.

Bits & Pieces sold a derivative called T Party, which extended 4-T Puzzle into a 3-dimensional puzzle by transforming the tray into a box with a lid, and by replacing the four T-shaped pieces with extruded aluminum segments.  The red pieces are cut from aluminum T angles.  Unfortunately the stock-sized aluminum didn't have the right proportions for this puzzle, so T Party has a number of unintended solutions other than the elegant one the designer intended.

Over time I grew dissatisfied with T Party because so many people who attempted it found inelegant solutions: arrangements that fit entirely inside the box, but didn't resemble the intended solution.  And it didn't exploit its three-dimensional design to accomplish anything new.

So I devised another three-dimensional adaptation with careful attention to all the specific ratios of height, width, and wall-thickness that would be required to replicate the behavior of the T-pieces in a square box.

I wanted the pieces to fit inside the box like they had in 4-T Puzzle, but I wanted there to be an added twist: that shouldn't be the solution to the puzzle!  But how to accomplish that?

Gotcha!  It's impossible to put the removable lid on when the pieces are arranged in the 4-T configuration because the pieces block access to the corner where the lid attaches to the box.  Users briefly think they've found the solution, but they can't close the lid--which unambiguously tells them they need to try something else!

To keep things interesting the asymmetrical pieces can fit together in various neat ways, but they can't all fit together the same way because one piece is a mirror image of the others.  I took advantage of a lot of testers' feedback while developing the puzzle, and tuned the pieces so they can fit and interlock in all sorts of fascinatingly distracting configurations.

The strange combination of pieces (3 left-handed and 1 right-handed) led many testers to think they'd gotten a mismatched set.  I embossed letters A, B, C, and D onto the four pieces to provide a visual confirmation they were correctly matched.

At the design competition Guile in the Box was exhibited adjacent to Tom Jolly's Little Window, another 4-piece packing puzzle handsomely crafted from manzanita and zebrawood.  Above, puzzle enthusiast Bram Cohen is trying to fit together Little Window after he'd already finished Guile in the Box.

[EDIT] As the founder of Bittorent Corporation, Bram Cohen got a bit of nice press today here.  It's so nice how well-connected everything is in the puzzle domain!

Wednesday, September 12, 2012

Success 2 - Its' Nuts!

In May I blogged how I built an enhanced copy of Oskar van Deventer's Cooksey Tribute D puzzle.  Oskar already owned a copy of Cooksey Tribute D, and so did I, so Oskar suggested I send the third as a gift to Jerry Slocum, a renowned puzzle enthusiast and author.

Coincidentally two other puzzle enthusiasts, John Rausch and Tyler Barrett, had recently persuaded me to build a small quantity of bolts with trick nuts like the ones in my Wrong Way Nut video so I chose to send one to Jerry.  That way Cooksey Tribute D would be a gift from Oskar, and Wrong Way Nut could be a gift from me.

For reference, here's the Wrong Way Nut video:

Jerry telephoned me immediately after he'd received the puzzles and asked if I could possibly build 120 copies of the bolt and nuts for the Puzzle Party.  I was thrilled!

We agreed the puzzle needed a name because I had originally adopted "wrong way nut" as a descriptive phrase, not an actual title.  Jerry researched to ensure we wouldn't infringe any trademarks.  I liked his suggestion Its' Nuts because it used an apostrophe in a nonstandard way, which was a subtle puzzle in itself.  Had it been intended as the contraction It's Nuts or a possessive term Its Nuts?

Each nut is embossed with "Its'" on one side and "Nuts" inverted on its opposite side so the puzzle's title appears when the nuts are correctly threaded onto the bolt.  Can you work out the probability of correctly assembling the bolt and its nuts so they say Its' Nuts?  (It's not just 1 in 2, as you might guess.)

It's customary for entries in the Edward Hordern IPP Puzzle Exchange to carry the name of the person exchanging them and the date of the IPP event when they were exchanged.  The bolts I built for Jerry are custom-embossed with IPP32 and the year 2012 on one face, and From Jerry Slocum on an opposite face.

With Jerry's approval, I added my own name to the top of the bolt head to identify myself as the creator.  Pay attention to how thin those letters really are, forming narrow strokes less than 1mm thick.

I deliberately made those hollow areas are narrower than 1mm so they wouldn't be sufficiently wide for the SD300 to apply anti-glue inside those narrow channels.  Consequently the letters are glued into the solid bolt head when the SD300 builds them, forming subtle outlines that can only be read by carefully examining the sheen of the top surface.

Screw threads need a slick finish, but the SD300 ordinarily builds layers with sharply-defined edges so I dipped every single nut and bolt in Weld-On 2007.

The solvent smooths and seals the layers, but after a few uses the solvent also tends to fog up the glossy top surface--an undesirable side effect.  To avoid fogging I learned how to dip the bolt only up to the sides of the hex-shaped head, but that left the side walls of the bolt head with a half-glossy/half-matte appearance.  The solution?  I wiped the side walls with ordinary PVC Pipe Primer from my local plumbing supply--it contains just enough solvents to impart a uniformly glossy appearance, and it includes a neat applicator.

This was a big project.  It took over a week to build all those bolts, and almost two weeks more to build all the nuts.  The nuts were more trouble than the bolts because I had to manually clear 72 layers of leftover support material from the center of each nut, tearing out the layers with a pointed probe as illustrated in this previous blog post.  It went at least twice as fast if I heated the model in my microwave oven for 30 seconds, a tip I learned from Jason Harris.

After the various pieces had been built, I assembled them into completed Its' Nuts sets.

I vacuum packed the bolt sets in groups for convenient shipping to Jerry.

For their final presentation Jerry repackaged Its' Nuts into individual prescription-drug containers, playfully labeled Slocum Pharmacy.  It included a caution, "Be sure to take with 1 grain of salt."

Jerry Slocum increased his order to 135 sets of Its' Nuts and I managed to build all 135 of them without any rejects or second-quality parts.  I sent him every single bolt I had built with the custom "From Jerry Slocum" inscription, and I forgot to keep one for myself!  I'm happy to build more bolts, but I wouldn't allow myself to build any more of Jerry's bolts--I regard them as a work-for-hire.

So I negotiated a puzzle-swap: he traded me one of the customized IPP bolts and in exchange I gave him this one-of-a-kind bolt that was professionally built via SLA, polished, and lacquered by a professional bureau.  To commemorate the occasion, I paired it with the very first nuts that had ever been inscribed with Its' Nuts.

Jerry Slocum won me over to the name Its' Nuts because the odd placement of the apostrophe struck me as a clever piece of word-play.  He later confessed that it originated as a typo.

Monday, September 3, 2012

Success 1 - International Puzzle Party 32 - Party Day

Each year the International Puzzle Collectors Association hosts a major puzzle event in various countries worldwide: the International Puzzle Party, affectionately referred to as "IPP" by those who attend it.  As a longtime puzzle collector I've really wanted to attend, but it's invitation-only and the guest list is carefully managed.  I was probably nominated on a previous occasion, without my knowledge, but was passed over.

My use of the SD300 has enabled me to become a puzzle creator, which connected me with several important people in the puzzle community and, in turn, won me a last-minute invitation to this year's IPP 32 in Washington DC.  So I attended the event in three roles: a puzzle collector, a puzzle maker, and a puzzle-design competition entrant.

Party Day would be a frenzied event where puzzle makers showcase their wares at tables in the hotel's large ballroom.  Puzzles and toys may be offered for sale or (preferably!) for exchange in hopes of bartering with other collectors for trades.  Although I'd never attended such an event, I reserved a table and anxiously formulated the best showcase I could devise.

But how could I create a showcase of amusements and transport it from my home in Oregon to Washington, DC, many thousands of miles away?  The deadlines were only two weeks away, so I had very little time to plan!
I solved both challenges by adapting the cartons from the SD300's material kits.  Gathering various containers from old supply kits, I found each shipping carton neatly held a modular collection of 12 small flip-top boxes and 2 larger tray-style boxes that had previously house glue and anti-glue cartridges for the SD300.  Bonus: I could use the inner cartons as additional shipping containers for puzzles I acquired in Washington DC!
I packed the boxes with puzzles and toys, and included an assortment of supplies that would contribute a festival atmosphere: battery-powered animated lights, sticky-note paper, markers, poster putty, and hundreds of zip-closure baggies of various sizes.
My showcase included a comical poster for Not So Strait of Dover, which was going to require some sort of easel or frame to display it.  Happily, I devised a simple 3D-printed device that converted Solido's tray-style box into a display-stand.  (inset above)  My table had things to look at, stuff to read, toys to play with, and puzzles for sale.  A satisfactory showcase.

It all worked, perhaps a bit too well for my tastes: I'd barely had time to frantically arrange things on my table when a deluge of puzzle collectors swarmed into the ballroom.  My table attracted a crowd that sustained so much attention that I didn't get a break for over five hours!  I only managed to get a picture of my table during the last hour, as things were winding down and my table was relatively empty.  (Thanks for taking my picture, Matt!)

I finally got a few minutes to visit a few other tables in the room.  Not enough time!  I especially liked this Puzzled Guy Bakery table, which featured exquisitely-crafted wooden puzzle boxes in the shape of petits fours.

And that just covers one frenzied, frantic day at IPP 32.  Later I will discuss the 3D model that comprised my entry in the puzzle design competition, and the story of the 3D model that won me an invitation to the International Puzzle Party in the first place!

Allard's blog Puzzling Times describes the Party Day experience from the other side of the table.

Brian Pletcher's blog has a great picture of the whole room, photographed right over my head!  (I'm the slouching guy in the black shirt.)

Monday, August 6, 2012

Not-so-Strait of Dover

Captain Angus ferried cars between Dover and Calais.
His patronage was dwindling, there were fewer cars each day!

So he bridged the English Channel with a winding two-lane curve.
Could it bring back the traffic that his ferry used to serve?

But halfway 'cross the span there arose an awful fight--
British cars kept left while the French drove on the right!

Traffic was all jammed, held up by long delays.
So he bypassed the first bridge with two one-lane motorways!

These were even worse because there wasn't room to pass!
But his ferry was full again, so Angus didn't give a rat's concern.

I contrived this silly "ferry tale" as a whimsical backstory for my Not-so-Strait of Dover puzzle.  Angus revitalized his ferry business by enticing drivers to a bridge so twisty and impractical that they were forced to take his ferry instead.

Puzzle bloggers have lately been discussing apparently-impossible card folding tricks, like this and that.  I could undoubtedly build something like it on the SD300, but the material it uses is so resilient that the results wouldn't so incredible as carving shapes from unbroken card stock.

But I was inspired to turn the concept around: rather than folding a flat sheet into impossibly-interlocked overlaps, I could instead design already-overlapped profiles that have to be folded to make them interlock.  I started with a simple design as a test.

The layers are built in three different colors, from blue on the bottom to white on the top.  Although the strands meander, you can clearly see that they aren't woven together: the white layer is always on top, the blue layer is always on the bottom.

But after some maneuvering (and a little guidance from Martin Gardner's books) the strands can be rearranged into a woven configuration without breaking any of the connections.  Now white weaves over blue and under red.  Blue weaves over red and under white.  Red weaves over white and under blue.

Most people are quite baffled by it, but the pieces can be endlessly woven an un-woven once you discover a solution.  Some users tangled the pieces, but found it to be helpfully resilient--it tends to spring back even after becoming quite knotted.  They've withstood a great deal of abuse, suffering no more harm than an occasional crease mark.

Friday, August 3, 2012

Yoshimoto Boxes

The Yoshi Box is a hinged toy reminiscent of the folding patterns of a Yoshimoto Cube, but it employs mechanical hinges to allow the pieces to be folded into a endless cycle of shapes.  The pictured model is available for purchase from Shapeways or Sculpteo.

This toy is made up of eight bisected boxes, each attached to two of its neighbors with mechanical hinges.  This sample was built in nylon SLS with the hinges already fused together.

The small tabs enable two models to be snapped together so they'll move in harmony with each other.  I suppose you could hide small treasures inside the boxes, too.

The inspiration for the Yoshi Box came from Yoshi Prime, a previous Yoshimoto-like toy I built on my SD300 using living hinges.  It's built in one piece with thin, flexible plastic connections that permit it to be folded in each axis.

Here's a closer view of a living hinge.  To build a vertically-oriented living hinge on the SD300 I bridged the connection between adjacent cubes with a wall 0.3mm thick, with a graceful curve to spread the stresses as much as possible.  I suspect it would have a limited life because of the amount of bending required, although it hasn't broken.  (Yet.)

This model combines the box-like style of the Yoshi Box with the living hinges of Yoshi Prime, forming a group of 8 small treasure-boxes connected by living hinges.

Friday, July 13, 2012

Indian Rupee Sign, Rev. 2

My first attempt at making the Indian Rupee into a letter-dissection puzzle was an interesting puzzle-design exercise, but it yielded a fairly uninspired puzzle.  I had designed a frame for the puzzle because most people aren't very familiar with the shape of the Indian Rupee sign, but the frame just made it that much easier to solve.

But I sensed a puzzle in that shape, so I drafted and modified the outlines to explore relationships between all the lines, curves, and angles.  Hidden relationships emerged as the shape evolved.

A new puzzle emerged with so many similar curves and angles that 8 of the 9 pieces could fit together without any of them being correctly positioned.  But was it a good puzzle?  No, not really.  My friends had no trouble identifying the correct positions, and some of them couldn't even discover those "wrong" positions without considerable effort!

The puzzle at right is solved correctly, while the puzzle at left is shown with all the pieces in wrong positions.  It was a failure, but a very instructive one.  So, could I re-design the puzzle so the correct positions were more like those in the puzzle at left?

Starting from scratch I designed a new layout, paying close attention to feedback from my testers.  What emerged was a dissection of a Rupee sign into just eight pieces.  Each piece fits into the frame in more than one location, but most look like there's only one possible place to put them--and it's usually the wrong place!

The classic T letter dissection puzzle requires four pieces for its relatively simple shape, so I'm thrilled to dissect such a complex shape as the Rupee sign with just twice as many pieces.  I had to allow some wacky variations in shape and size, but it works.  Moreover, the frame actually enhances the challenge by discouraging the user from removing pieces that might have been incorrectly placed!