# Martin Gardner, board games and 3D printing Bashny.Net

In previous publications about Designer Kubotronik (and the beginning here and here ) we pulled into the light the book Martin Gradnera "Math Puzzles & ENTERTAINMENT" and just put it down have not been able to.

We bring you the materialization of one of the logical problem that is described in this book. That is the problem itself, and drawing from the book:

"Puzzle with shunting locomotive. Making trains often leads to difficult tasks in the field of operations research. A problem with a shunting locomotive shown in the picture, has the advantage that combines the simplicity of the formulation with surprising difficulty solutions ».

Figure. Puzzle in the field of operations research.

The tunnel is wide enough to move freely around and through it the locomotive, but narrow for cars. The problem is that using diesel locomotives, swap the upper and lower carriages and the locomotive back to the starting position. The locomotive can pull and push the cars in front and behind. Wagons, if necessary, can be engaged with each other.

The best is a solution in which the desired result is achieved by the least number of operations. Under the "transaction" is defined here as any locomotive running between two stops (stop the locomotive before you start moving in the opposite direction, when approaching the car, you want to push, or when it is uncoupled from the train, which before he was pulling for themselves). Translation arrows operation is not considered.

In solving the problem easy to use visual "model": putting the figure at three coins of different denominations, they move along the rails. Not only need to remember that through the tunnel can only pass the coin depicting a locomotive. Figure car is too close to the shooter. In solving the problem, you can assume that both the car are much more "east" and the segment path that separates them from the arrows, can accommodate locomotive with another car.

Put the arrow "on the move" is not allowed. For example, it is impossible to translate the arrow at a time when the locomotive just pushed through it is not linked with him wagon to wagon rolled on one branch, and the locomotive, without stopping, continued movement on the other. & Quot;

In general, the text of the problem, is directly written & quot; ... easy to use visual "model": Put a figure three coins of different denominations, they moved on rails .... & quot ;, so where the author of a coin, drawing and other restrictions, we design, choosing the right strategy of building "without supports», 3D printing on our printer and assembly.

At the beginning we tried to create test items to test, including visually and tactilely, as it feels and looks. The photo shows that cornering has been chosen two rackmount chassis chips, and in consequence there was a jumper to avoid ambiguous passage of the arrow with a "tip." The chip is often unfolds to two possible outcomes.

Then, there was work on the bugs, and the final version of which can already be given to children as puzzles. Please note that nowhere call for chips that move. This is done intentionally to make it smaller parts, and locomotives and the cars are inserted on the arrow at an angle relative to the straight sections. Provided, and a restriction on the movement of cars made artificial narrowing, there is only black chips can drive the locomotive.

After the first field ready, once there was a need in the second, maybe somebody said, "and I want to try." You can now compete in pairs, who is faster.

At the same time competitively-reshatelnym process, the question arose as to be a girl, with the railway boys like to play more and we have to come up with new scenarios of the game, changing the images of the characters and of their assignment.

By the way the chips can be styled like a real wagons and locomotives, and the rest under the fictional characters.

Here are examples of additional options for jobs have not come up on railway theme:

Characters Mole and baskets. One empty and it should be put under the entrance to the burrow to load and full must be removed. And in one place hole is very thin and there is only a mole can crawl through and get stuck baskets.

Characters Mouse and coach, one of the pumpkin carriage, the other real. Mouse should be pushing to change the usual Magic coach and then a coach Cinderella disappears. On the roads you can ride, but the bridge over the river can run only the mouse and obbegat carriage on the sides can not only pull or push.

Downloads playing field and chips you can take from our site . The total weight of the resulting board game about grams 20 grams, which means that the price of less than 50p a useful solution that is very, very good at present.

And if you have any suggestions for characters and attributes for this logical game, we hear them with joy and listed in the description of the files to be printed to the parents themselves can tell the children fairy problem of their choice.

We also think that it makes sense to store printing solutions such materials to those parents who already have the device for 3-D printing, and were able to use it to save money on the purchase and delivery of a variety of developmental benefits for children of all ages.

P.S. Children's Railway in the version of Martin Gardner, and then everything - rails, rails, sleepers, sleepers riding the train ...

Material provided by the Master Kit DIY.

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