Category Archives: Juguetes


A toy for sharing with our daughter

On this occasion we suggest you to make a toy for your kids to share your workspace, is that, even though the Three Kings just left their gifts, our daughter (as is usual in children) seems to have more fun playing with our things as with hers, and since she learned to whistle the multimeter (set to check continuity), every time she has it on hand what, she brings it asking us to turn it on.

It’s been a while since the last time we wrote, and we apologize for that.

It’s been a hard time for our family, but gradually return to normal.

As there seems not very reasonable to let a toddler to click anywhere, I decided to do a toy to make the tester whistle while we work.

It is a simple game to find pairs, touching at points that are connected together.

While it is true that in order to play you must have a multimeter at home (and not everyone has it) it can be done with any broken toy at home, after all this wiring will replace the switch. Anyway this toy has been specifically made to take advantage of the interest that our daughter has in the multimetermeter and will be used under supervision, children should not play with these things if we do not know what we do.

We need a table, fat cardboard or sheet of any material (which does not conduct electricity, of course), images in couples to stick on the table, rivets with tab, cables, soldering iron, tin, hot glue and something to cover the cables behind when finished.

It’s actually so simple that needs little explanation, so I leave the pictures and little else.

1.- PVC table and stickers.


2.-Stickers placed randomly (half right and left but messy)


3.- For each rivet a hole (3mm) is made and inserted next to each sticker.


To prevent them from turning and thus can remove the cables, I glued each rivet  with hot glue.


This is the look ahead:

resized_frontal4.- When wiring, I try to stay wires tidy and hold them with glue. Be welded on each side, or if we don’t have a welder, you can wrap the cord at the ends of the rivets and secure with silicone.


5.- Finally we cover the wired surface with felt, foam or EVA which is what I used, so they are no wires and ends in view, and does not spoil. Then I fixed the edges with masking tape.


That’s it, ready to play, match and beep all she wants, and when we use the tester, María can make use of it and have fun with us.



And besides of having fun, she is slowly making contact with these things as I did as a child.

This reminds me, by the way, a work I did in school, that time when we were sent to make a simple circuit that would light a bulb, and I (with advice from my father, of course) made a map of Spain that lighted up when you matched each province with its name … the result was that the teacher said that I had not done it …. And I said (with all my tranquility) that if she wanted the next day I would carry the materials to class and taught her to do it. Finally she let it go.

A gift for train enthusiasts


We show you one of the last commissions that we have made.

tren2 (Large)

tren1 (Large)

It’s a railway model of the Steam Locomotive RENFE 040 (PIKO) Epoch III. H0 scale.

tren4 (Large)

It is mounted on a methacrylate urn with an inscription that some colleagues have commissioned for the retirement of a fan of trains.

tren3 (Large)

Is mounted on a section of track, so that is still functional so that the recently retired still can play with it if he wants.

Thanks to our great friend Sebastián Salvador, for teaching us the little tricks of this world.

If you have any railway model enthusiast friend, this is the gift you guys were looking for.

Pythagorean Theorem




“In any right triangle the square of the hypotenuse equals the sum of the squares of the legs.” Pythagoras of Samos

Demostración de Euclides
Demostración de Euclides

There are hundreds of demonstrations of this theorem (ES Loomis, cataloged 367 different tests, other authors speak of 1000), more than any other mathematical theorem. These tests have been designed by people from very different condition from which a Babylonian magician, a student from Ohio 14 years old with a normal intellectual level, the math genius 21 Galois and  James A. Garfield, who became president of the United States in 1881.

Chou-Pei Suan-Ching (hacia el 300 a.n.e.)
Chou-Pei Suan-Ching (hacia el 300 a.n.e.)

A persistent tradition documentary based on Vitruvius, Plutarch, Diogenes Laertius, Ateneo and Proclus, the Pythagorean Theorem attributed to Pythagoras himself. But archaeological discoveries of the remains of the cultures of Mesopotamia, Egypt, India and China, have revealed that these civilizations known aspects of the Pythagorean Theorem many centuries before this wise. The references of  this pre-Hellenic Theorem don’t contain , however, tests of the same, while it is generally believed that it was Pythagoras (or any of his disciples) the first to provide a logical proof of Theorem, which will make it right there passed into history with his name.

Demostración de Perigal
Demostración de Perigal

Another important reason for the large number of existing demonstrations reason is that in the Middle Ages a new demonstration was required to achieve the degree of “Master Matheseos”. We found more or less intuitive, algebraic, geometric and graphic demonstrations, (Pythagorean puzzles). Even art has caught the spirit of this theorem, which has inspired many artists.

William P. Haas, La visión de Pitágoras (1993)
William P. Haas, La visión de Pitágoras (1993)

From encouraged us to build one of the simplest, so that at a glance and in a fun way we can verify that indeed, if a right triangle has legs of lengths a and b, and the measure of the hypotenuse is c, states that:

                                            c^2 = a^2 + b^2 \,

Here we present our practical demonstration on a fridge magnet. We just have to turn it to fill the surfaces (volumes, but for the visual effects we take them as surfaces) of the legs or the hypotenuse respectively.

Pythagorean Theorem demonstration

It works like an hourglass, a mathematical clock ….
pi1 (Large) pi2 (Large) pi3 (Large)It is available in our store, if you belong to a school or other group interested in buying multiple units please contact us so that you make a budget. (Pythagoras Magnet from MJ2Artesanos).