Kit #41, The Auto Writer

(Image from the Gakken site. Used for review purposes only.)

At some point, Gakken stopped printing volume numbers on the Otona no Kagaku kits, but they kept them in the online URLs.

(Starting out. Note the thing at the top of the photo that looks like a stir stick. It’s used for prying the cams off the cam spindle when you want to change patterns.)

Auto Writer, kit #41. 3,500 yen (w/o tax).
The original image for this kit, released almost 9 months ago, was of an old-fashioned automaton dressed up as an 19th century woman. The actual implementation is something a bit different. Novumichi Tosa, president of the art company Meiwa Denki, was instrumental in the design and testing of the kit, which kind of looks like a clown hand on a cassette tape player. The name is a gag – “automa-te”, which is derived from “AUTOMAton” and “te” (for hand), or “automate”.

(Top half, top view, with cam sliders and power button in place.)

The mook starts out with a look at Meiwa Denki, and the two brothers running the company, then discusses the development and principles behind the kit. Several pages cover the operation of a full-scale machine writer used for transcribing kanji for art prints, which is followed by a pictorial on how the cams were made for the kit. We then get a photo history of several automatons,including one of the machines by Friedrich von Knauss, and three by Pierre Jaquet-Droz. The suggested mods are to turn the kit into a UFO to make mini-crop circles, clamping two kits to a guitar to play music, and interfacing a tablet computer through an Arduino to make a kind of plotter/printer.

(Top half, bottom view. Cam slider mounting.)

There’s a section on robotic prosthetics for the handicapped, examples of figurines made using 3D printers, and a hand-held 3D doodler (think hot-glue gun that makes 3D structures) ($160). 6 pages on what the 4th dimension would look like, 2 on what children think space looks and sounds like, and 2 pages on a guy that makes model Japanese castles out of cardboard. 2 more pages on a guy that hand-makes actual transformer robot models (they change from a car to a robot), and 2 pages of entries from last year’s “15-Second Special Effects Movies” contest.

(Bottom half, top view. DC motor and gear chain. The kit uses one AA battery.)

Have you heard of “rare sugar”? I haven’t. There’s a 6-page section on “kishoutou”, which literally translates to “rare sugar”. The Japanese wiki has a page on it, but there’s no English version. The primary link is to the Rare Sugar Research Center, located in Japan. The website is Japanese, only. Example sugars are D-Allose and L-Glucose. Rare sugars seem to be promoted as having special health properties, but there’s some dispute over this.

(Top half, top view. X-axis and y-axis sliders in place.)

The rest of the mook contains construction instructions for the kit, and ends with Yoshitou Asari’s Manga Science (this one on water surface tension).

(Top half, top view. Mounting the hand. Note that the springs for the hand and the x-axis slider are in the wrong places. The black piece in the hand casing is just used to hold the pen.)

The kit is based on the same principles as the von Knauss and Jaquet-Droz machines. 3 separate motor-driven cams control the x-, y- and z- axes of the pen hand, and the movement along the slider bars is pretty much the same as for a plotter. Only the x-axis slider is directly connected to a cam lever. The y-axis slider is advanced with fishing line tied to one cam lever, pulling against a spring. The z-axis works the same way for lifting the pen off the paper. Two ribbed pieces of tubing are used to maintain tension on the fish line between cam lever wall and the connecting wall on the pen arm. This is where the first error comes in. The parts list photo shows the 2 pieces of tubing to be the same lengths, while the instructions refer to a “long” piece and a “short” piece. If you use the tubing as-is, the fish line for the z-axis will be too short. I ended up cutting 2″ off of one piece to use it for the z-axis, and even then there was more tubing than is needed to compensate for the action of the sliders.

(Top half, top view. Putting on the upper hand cover, and mounting the top and bottom halves of the main unit together. Tubing to the right is for the fish line controlling the y-axis movement.)

A second problem comes in with the springs. There are three springs, one for each axis, labeled as “big”, “medium” and “small”. The big spring is used for the y-axis, and it’s pretty obvious which is the big one. However, “medium” is the same diameter as “big”, just a bit shorter; while “small” is the same length as “medium” but with a smaller diameter. If you mix up medium and small, you’ll mash up the x-axis spring when you tighten down the screws, and the z-axis spring won’t fasten right under the smaller screws. So, use the smaller diameter, shorter spring for “small”, and larger diameter, shorter spring for “medium”. Regardless, the x-axis spring should be another 10% shorter in order to fully retract the slider arm to the “resting” position; as it is, it’s too long.

(Bottom view with both halves mounted together. The ribbed tubing shown here is for the fish line controlling the hand z-axis. Note that one end of the line isn’t connected to the hand, yet. I think the key-hole in the case is so you can hang it on the wall when not using it.)

The fishing line is held in place at one end with a knot, and the other by wrapping it around a screw. When you get the kit fully built, it’s a good idea to loosen the screws to take all of the slack out of the lines. And again, after you’ve played with the slider arms to see how they work, it might be wise to shorten both ribbed tubings to get rid of excess that could get snagged on something.

(Bottom view. Rubber feet attached to the case. Fish line attached to the hand for the z-axis movement. Spring wire inserted in the disk at the top left. That disk is a retainer used to hold the cams in place on the main gear spindle.)

You get three sets of cams, one for the kanji that appears on the front of the mook, one for the name “Tosa”, and one for a peace sign. While the full range of the sliders is about 2.5cm x 2.5cm, the height of the kanji is just over 2cm (3/4″). So, while the auto writer is a fun idea, what it can write “out of the box” is kind of limited and kind of small. If you want to make your own personalized cams, you can design them using an online app, trace the patterns out on a thin sheet of plexiglass and cut them out yourself. Personally, I don’t have plans for making new cams or for modding this kit. I thought of using it to move the stylus for the Pocket Miku, but the note play time would be too slow.

(Top view. Cams and cam retainer in place.)

A couple final notes. There are actually 2 switches on this kit, wired in parallel. The first one is the push button mounted in the corner, with the light blue button cap. You need to hold this down for about a second for the kit to go into auto mode. The second is a leaf switch driven by the main drive gear at the bottom of the kit. As the gear starts rotating, it closes the leaf switch, which lets the motor continue running after you let go of the push button. When the gear makes a full rotation, the leaf switch reaches a notch in the gear and opens up, causing the motor to stop. It’s a fairly elegant way to avoid using an electronic timer circuit.

(Using the “kanji” cams. The arm kind of sticks during movement, so it may be a good idea to spray the slider rods with lubricant.)

The second note regards what to write with. The hand doesn’t push down against the paper all that hard, although it does push enough that the pen will drag the paper around unless you hold the sheet in place with something heavy. If you use a pencil, the writing will be too faint. You can use a good ballpoint pen, a thin-line marker, or a paint brush. I suggest turning on the kit, and when the hand goes into full “down” position, pull the battery out. Put the pen in the hand and adjust the positioning so the pen writes the way you want on a sheet of test paper. Wrap masking tape on the pen to show where to slide it next time when you remove it or cap it during storage. Put the battery back in and wait until the kit turns itself off. Put a fresh piece of paper under the pen, anchor it in place, and then start the kit again.
The next kit is scheduled to be the electronic steel drums, 3,500 yen, in September.

Newsletter 160

Gakken is announcing new kits, and that means the release of the next newsletter. It starts out by commenting on how magical machines look when replicating human writing, then goes into the Table of Contents.

1) Release of the self-propelled nonsense machine: “The Auto Writer”
2) Aug. 9, an Auto Writer Workshop
3) Release of the Rainbow Loom Starter kit
4) Yoshito Asari’s “DIY Rocket” book wins the Seiun Award
5) Now accepting applications for the High School Furoku kit idea contest, #2


1) Auto Writer
This section describes the contents of the Auto Writer mook, and how the president of Meiwa Denki helped develop the kit. The Auto Writer went on sale today (July 22), for 3,500 yen ($35 USD) not including tax. It is accompanied by a 100-page A4 mook.


2) Auto Writer Workshop
Fabcross is going to co-sponsor a workshop on Aug. 9, at Loft&Fab in Shibuya, Tokyo, for anyone wanting to learn more about how to use the kit. Participants will create their own cut-outs for decorating their kits.


3) Rainbow Loom Starter Kit
The Rainbow Loom is primarily aimed at girls, and uses brightly-colored stretch bands for making bracelets, anklets and rings. The kit comes out on Aug. 5, and includes a 28-page guidebook, loom and a set of 10 colors of bands. 1,200 yen.


4) Asari Wins
Gakken manga artist, Yoshito Asari, creator of “Manga Science”, wrote the book “Building a DIY Liquid Fuel Rocket“, documenting the amateur rocketry group that actually made the rocket and successfully launched it. “Building a DIY Rocket” won the 45th Seiun award for non-fiction works. Seiun, which translates to “Nebula”, is the Japanese competition that recognizes leading SF and non-fiction science works, and is presented at the annual Japan Science Fiction Convention. “Building a DIY Rocket” came out Aug. 28, 2013, for 1,300 yen. 224 pages.


5) HS Contest
Gakken is now taking applications for the second annual High School Furoku Idea Contest. “Furoku” translates to “supplement”, and refers to the kits that are packaged with the Otona no Kagaku mooks. The idea is to encourage students to create science and technology projects using existing OnK kits, or that could be turned into new kits.

Korg DSN-12 new release

I’m on the Korg mailing list. Generally, this just means getting ads for promotional campaigns for gear like guitar effects pedals and the occasional contest. This time, though, is a bit more interesting, from my perspective.

(Images from the Nintendo e-shop, used for review purposes only.)

On June 25th, Detune released a new Korg synthesizer in Japan – the DSN-12, for the Nintendo 3DS. One good point is that it’s a lot cheaper than earlier products – 3,800 yen (not including tax), which is less than what I paid for a used copy of the M01. I haven’t tried translating the Japanese page, but it looks like the DSN-12 is based on the MS-10, and has many features similar to the M01 and DS-10+ Gameboy emulators, such as the sequencer, mixer, synth knob and synth patch cord interfaces. A big departure is the inclusion of the “o-scope” display for the audio waveform. It’s advertised as an analog synth, which I’m not sure how that would work on a digital game console, but I guess it’s possible.

Now I have decide whether I want to drop the change on a used 3DS just to be able to play this thing. Sigh.

Auto Writer Kit Update

We have an official cover photo for the auto writer kit! The release date is confirmed for July 22nd. The page showing the articles in the mook has fewer pictures than normal, but the assembly instructions look a bit more complicated this time, with close to 40 pieces, not including screws. Priced at 3,500 yen ($35 USD), it’s kind of expensive for what you get, so hopefully it’ll be a fun kit overall to make up for the cost.

It’ll take an additional 2-3 days for the kits to make their way to Kyushu, so I’ll write up the review after that.


I should also mention that the next kit up is to be an “electronic steel drum”, 3,500 yen, coming out in September. That could be very cool.

Kenning Kenken

What the heck, I’ve got a little free time. Just for the practice, let’s use a 5×5 Kenken grid from the “official” site.

The rules still hold – use all of the numbers 1 through 5 once and only once in each row and column. Apply the arithmetic operations in the cages to arrive at the specified totals. Digits can appear more than once in a cage. Start with the 1-cell cages and just plug those numbers in.

Ok, the largest and smallest sums, and multiplications, usually have restricted answers. Just for amusement, let’s do “10+” on the third row. 3-digit solutions with non-repeating digits (using only the numbers 1 through 5) are “1+5+4” and “2+5+3”. Since “3” is already used on that row, we HAVE to use “1”, “4” and “5” here. Just plug the numbers in any order right now. We’ll make corrections when/if necessary.

We can now fill in the first cell of row three, and tackle “11+”. This has to be “5+4+2”. Since the last cell of column 1 has a “1”, we can complete the column with “3”. The order for the “5” and the “4” is unimportant at the moment.

Right now, you may be wondering where to go next, and it could be a bit bewildering at first glance. However. We have logic working for us. With “6x”, and being limited to only “1”, “2”, “3”, “4” and “5”, the answer has to be “2×3”. With “2/”, we have “4/2” and “2/1”. And with “7+”, with “3” already given to us, the only solutions are “3+2+2” and “3+1+3”. The thing is, with “3+2+2”, both “2’s” would be in the same column. For “3+1+3”, while the “3’s” would be repeated in the cage, that’s ok because we can arrange the digits to keep them unique row- and column-wise. So, the “7+” cage goes first, and that dictates the order to “6x” on the top row. and “2/” on the second.

Again, the puzzle becomes almost self-solving. Obviously, I got the order wrong in the first column for the “5” and the “4”, so let’s correct that. But, the remaining “10+” becomes really easy because we’ll be using both the “5” and “1” on the first row, and the “3” and “1” on the second row (1+1+3+5=10). It does look like this is impossible because we’ll get “1” two or three times in the fourth column, but that’s just because the order of the “4” and “1” on the third row also needs to be corrected. Let’s do that.

“3-“, with only 2 digits not including “1” HAS to be “5-2”. There’s already a “2” in the third column, so the order is pre-defined.

All that’s left is to fill in the last few numbers to complete the rows and/or columns, and to error-check that the answers satisfy “1-” (5-4) and “2/” (4/2). (They do.) And, that’s it.

Yes, I Kenken

I’ve been doing Sudoku puzzles for years now, but mainly those on the Yahoo games site because that limits me to one a day (otherwise, I’d buy Sudoku books and try to finish the entire book in one sitting). Recently, I’ve noticed ads on the Daily Sudoku page for something called KenKen. To me, the name looks stupid, so I’ve tried to ignore it. However, curiosity got the better of me one day and I decided to at least find out what it is.

For those of you unfamiliar with it, KenKen is a registered trademark of some company in Japan for a logic puzzle kind of similar to Sudoku, the name being the character for ‘wisdom’ used twice. You get a grid, which is usually 4×4 or 6×6, but it can be of any size. You then put the numbers from 1 to the grid size (1 through 4, or 1 through 6) in the boxes so they appear once and only once in both the columns and rows (just as with Sudoku). The difference being that there are “cages” (areas marked out with heavier lines) containing clues. These clues mean that the numbers in the cage have to total some value based on the associated arithmetic operation. So, if you have “1-“, you’re going to subtract the numbers to get the answer “1”. If it’s “8x”, then you multiply all the numbers in the cage to get “8”.

It’s ok to have the same digit repeated in the same cage, just don’t repeat the same digit in a single row or column. All Kenken puzzles are supposed to have a single, unique solution.

Start out with a simple 4×4 grid puzzle.

Notice that sometimes some of the cages only consist of 1 square. These are your starting points. Fill in the appropriate answers.

Next, notice the 2-square cage marked “7+”. This is another good starting point. Since the two values have to be different, there’s only one answer – “3 and 4”. Don’t worry about the order right now, we can always correct it if necessary later.

The top row obviously is missing the “2”, so fill that in. And while we’re at it, let’s solve “8x”. The first number has to be “2”, meaning that the other two values have to be “1” and “4”. Since there’s already a “4” on the third row, the correct answer is going to be “2”, “4”, “1”.

Ok, so now I catch my error. We started with 4 in the third column, so I should never have put the first row 4 where I’d had. Let’s fix that and address “2/” at the same time. Because 4 has already been used on that row, we can’t use “4/2”, leaving only “2/1”. Again, no need to worry about the order right now.

We can now fill in the last number of row 2, and solve “1-“. The only option for the last number is “3”, and to get “1” we have to subtract 2.

The puzzle is virtually self-solving now. The second number on row three has to be “3”, and the last number of column 1 also has to be “3”. To get “8+”, we need to add “3+2+3”, which puts the “2” in the second square of the bottom row. As a reality check, go back up to “2/”, where I put in “1” and “2” on the second row. If my order had been wrong (“2” then “1”), we’d have to correct that now. That just leaves “3-” at the end of the bottom row, and by simply filling in the missing values of the last two columns we just need to make sure we have the proper answer (“3”).

With a little practice I can easily solve an easy 4×4 grid Kenken in under 1 minute. This is a good way to get started with Kenken, but it’s obviously going to lead to much larger, much more time-consuming grids. And that’s a drain of my time that I’m not willing to commit to.

But don’t let that stop you.

Gakken Facebook Update

Two new photos on the Otona no Kagaku facebook page, both from the engadget FES2014 event held at the 3331 building in Tokyo. One includes the president of Maywa Denki. The photos will appear in the mook for the next kit.