Kit 30: Animaris Ordis Parvus

Gakken Otona no Kagaku Kit #30 – the Animaris Ordis Parvus, 3500 yen (approx. $45 USD). This kit is a miniature version of one made by the Dutch physicist-turned-artist Theo Jansen. You can see more of his work at his website.

The key element of Theo’s creations is a linkage mechanism, called the Jansen Linkage. According to Jansen himself, this mechanism has 11 dimensions, based on rod length and pivot point positions, that can be calculated to create a specific foot path. By placing several of these feet side-by-side in a phased stepping pattern, you can get a very smooth horizontal movement, similar to what you get with a car tire with a shock absorber. The difference is that by having feet instead of wheels, a mechanism can move more easily across sand.

Jansen’s concept is to have a series of machines using the Jansen linkage roaming along the beaches near his home. The machines are powered by wind pushing against the banners making up the “spine” of the “beests”, and they’re generally built out of PVC tubing, although there are some “species” using other materials. The beests can “think” in a fashion. A hose attached to the nose of one beest can sense when it gets too close to the water, alerting it to turn around and go the other way. Energy from the wind can be stored in the form of pressurized soda bottles to allow the beests to keep moving when the wind dies down. Another set of soda bottles interconnected with hoses forms a 6-8 bit “brain” to allow the beest to make simple decisions, and a mechanism that pounds a stake into the ground lets the beest anchor itself during a heavy storm. Overall, “beests” are powered by mechanical forces, and use mechanical systems for decision-making and situation analysis.

The release of the Gakken kit coincided with the exhibit on Theo Jansen that was held at the Tokyo Miraikan (“Future Museum”) in Odaiba, until Feb. 14, 2011. Admission was 1800 yen ($24 USD) for adults.

(Putting in the feet)

This kit has close to 100 pieces, and a recommended construction time of 90 minutes. For me, the most time-consuming part was in removing the extra plastic from the pieces with a cutter, and putting the feet on the legs. Most of the instructions are all pretty self-explanatory and you can follow them just from the pictures. The most difficult thing for me was in trying to figure out the first step. This is where you’re being told to put the feet on the legs, but the picture is confusing. There’s a strip of 13 little rubber feet. You tear one off and push it into place in the holder gap of one of the 12 legs (this will leave one foot left over). There’s an easy way for the foot to slide into place, and a hard way. You can figure out which is which pretty quickly.

(Leg assemblies)

Once the feet are in place, build up the leg assemblies. When you have all 12 legs, start building the frame. You take a frame piece and connect it to one of the two crankshafts. Then, use the connector rods to attach one leg on each side of the crankshaft, attached to one crank rod. When the first two legs are attached, put on the second frame piece and go to the next 2 legs. When all 6 legs are attached, add the last frame piece, and then do the second half of the beest.

(If the frame looks like this, you did it wrong. You have to build up the frame as you put each pair of legs on.)

If you look at the finished assembly detail you can see that the connector rods from the legs to the crankshaft have a specific location order. The connecting rods do naturally want to attach in this order, so it’s not too difficult to get this right. Basically, you’re just trying to avoid the feet from hitting each other. Note that you don’t need any special tools for this kit – just the exacto knife if you want to remove excess plastic from the frame joints. The final product is about 4″ tall and 6″ long.

There are a lot of different mods suggested in the mook. The first and foremost is motive power. The normal power source is wind against the fan blades. But, unless you have a really strong wind, it’s not going to move. The second alternative normal source is to connect a plastic rod to the drive shaft using a rubber tube connector and turn the rod by hand. But, the connector piece may be too elastic and may just twist around itself instead of turning the crankshaft. The first real mod is to take a piece of one of the frames, trim it, and use it to wind up a rubber band to turn the crankshaft. This works, but you need a drill if you want to put a hole in the frame piece (otherwise, no other tools needed). After this, other mods include connecting two beests in series or parallel, running them with a solar-panel driven motor, or using two 3V motors to run 2 beests driven by a Japanino.

(Correctly assembled frame with legs.)

My beest has a problem with relatively high torque on the drive shaft, probably caused by the legs rubbing against each other. This makes playing with it in the wind troublesome. Putting a weight on top makes the beest move more smoothly along the floor, but doesn’t address the torque issue. I think that using the wind-up rubber band, or a 3V motor with a connecting gear, is the best way to go. Please note, though, that the Otona no Kagaku troubleshooting page states that this problem is caused by connecting the legs in the wrong order to the crankshaft, so it may be fixable in most cases.

The mook consists largely of articles on Theo Jansen and his creations. There’s no real “history of the main topic” section this time, since nothing like the beests pre-dates 1990. There is one article on modern kinetic sculptures, a good 10 pages on mods to the Animaris and variations on Theo’s beests, and 10 pages on making the Japanino-driven bluetooth-enabled RC duo-Animarus. The hobbyist highlight corner has sculptures carved from toothpicks, a worm mechanism, and ships made out of recycled paper. There is one article on the mechanics and motion path of a Jansen linkage, and comparisons to how flesh-and-blood muscles move. Finally, there’s a 12-page manga on products that cause hair regrowth in balding men.

Links from the mook:

Steel beest
Lego Beest
RC Walking Robot
Steam Spider
Strandbeest Desktop
Street Beest
Theo Jansen Walker
Schnee Beast
Straw Jansen
Papercraft Theo Jansen’s Mechanism


An unfortunate side effect of time is that after a while prices go up. When the putt put boat first came out in 2003, the Gakken kits ran around 1600 yen apiece. The first price bump occurred 18 months later, and by 2006 the kits were 2100 or 2200 each. The really big jump came on Dec., 2009, with the electric guitar, at 3675 yen, but the prices dropped a bit to between 3300 and 2950 since then. Because the kits have been fairly complex lately, the increased prices haven’t been that distracting. The Animaris Ordis Parvis, though, is 3500 yen and if you get it as an import in the U.S., it will probably be between $70 and $90. Are the Gakken kits worth this much money now?

For the Animaris Ordis Parvis, the answer is “maybe”. If you have the Japanino, you can connect up a motor, solder in a bluetooth module on the Japanino, and play with the Animaris as an RC car.

But, for me, the kits are getting a little too expensive for what they include. The electric guitar suffers from an inability to stay in tune because the strings get stretched out of shape too quickly, so I can’t really play it much. The Edo Clock is noisy, with the ticking being really loud late at night, plus it needs to be readjusted to correct for the changes in daylight all the time. The origami lantern is nice, once you decide on the lantern cover to put on it, but if you have the Japanino, you can make the lantern yourself just by buying a $2-$3 tri-color LED. The Japanino is the only kit that I’m still using 8 months later. Bottom line is I think that it’s becoming more important now to decide in advance just what you want out of these kits. If you like learning about the science behind a specific kind of technology, and you like building stuff, these kits are still worth the price. If you’re looking for toys to play with, and things to kill time with, you’re better off just buying commercial products designed for specific tasks – such as a digital clock, a lava lamp, or a Gibson Stratocaster. What this means is that I’m buying the Animaris to be able to review it here. A few weeks from now, I’ll be trying to find a good home for it to make room on my shelves for things I really want to keep long-term.

On the other hand, the kits seem to be coming out less frequently. Originally it was 4 kits a year, at roughly 3-month intervals. But, it looks like there’s going to be a 6-month gap between kits 30 and 31. I don’t know what Gakken’s strategy is, but it may be one of fewer kits per year, with higher-quality, more expensive kits.

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  1. Jansen DVD mook « threestepsoverjapan

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