Hace una semana más o menos, terminé de hacer una baranda de casi 10 m de largo y 0.60 de altura, para la terraza de mi hijo. Cuando necesité cortar a 45 grados los caños cuadrados de 4x4 cm para hacer el marco exterior, me encontré con que el soporte vertical que había comprado para la amoladora no me servía. Anteriores experiencias me aconsejaron no intentar cortar "a mano alzada", porque eso sale siempre mal. Así que tuve que interrumpir la construcción de la baranda para hacer la escuadra para ingletes que detallo a continuación.

A week ago or so, I ended up making a railing about 10 m long and 0.60 high to the roof of my son. When I needed to cut 45 degree the 4x4 cm square pipes to the outer frame, I found that the vertical support I had bought for the grinder does not served. Previous experience advised me not to try to cut "by hand" because that always goes wrong. So I had to stop construction of the railing to make the miter square I will outline below.

Step 1: Los Catetos (hicks)

Tomé un trozo de hierro ángulo de 3/4" de ancho por 1/8" de espesor y le hice en el medio un corte en V, de manera de poder doblarlo cómodamente a 90 grados como se ve en la foto. El secreto para esto es hacer que la punta del corte en V llegue hasta la mitad del espesor del hierro, o sea que quede un espesor de aproximadamente 1/16", muy fácil de doblar sin que se quiebre. Eso simplifica mucho la soldadura, al no requerir herramientas de sostén.

Al doblarlo me aseguré de que el ángulo resultante sea de 90 grados. Luego le apliqué un punto de soldadura en donde se unen ambas pestañas. Como la soldadura encoge al enfriar, tuve que retocar el ángulo para volverlo a hacer recto (ver instructable de Phil B al respecto). Esta tarea fue muy fácil, consistió en algunos golpes de martillo sobre la soldadura para estirarla ligeramente.

I took a piece of angle iron 3/4" wide by 1/8" thick, in the middle I made a cut on V, so can bend it comfortably at 90 degrees as seen in the photo. The secret to this is to have the tip of the V-cut reaches half the thickness of the iron, so it remains a thickness of about 1/16", very easy to bend without breaking. This greatly simplifies the welding, because requires no tools to support.

When bending I made sure the resulting angle is 90 degrees. Then I applied a welding point where both tabs meet. Due to the solder shrinks when cools, I had to tweak the angle to do it right again (see Phil B instructable about it). This task was easy, was in some hammer over the weld to stretch it slightly.

Step 2: La Hipotenusa (the Hypotenuse)

Corté otro trozo del mismo perfil de hierro, con largo suficiente para funcionar como hipotenusa, entrando en la parte interior de ambos catetos. Lo aseguré a estos mediante algunos puntos de soldadura. En la foto se ve en qué manera ensamblan la hipotenusa con los catetos. Medí lo más cuidadosamente posible los lados del triángulo antes y después de hacer las soldaduras, para asegurarme de que ambos catetos fueran de la misma longitud (triángulo isósceles).

Cut another piece of same angle iron, with sufficient length to function as hypotenuse, fitting the inside of both legs. I assured those with some soldering points. The photo is seen in how the hypotenuse to assemble the legs. Most carefully I measured the sides of the triangle before and after welding, to make sure that both legs were of equal length (isosceles triangle).

Step 3: C�mo Se Usa (how to Use It)

La hipotenusa funciona como base, proyectándose hacia abajo y proveyendo así una guía para apoyar contra el perfil que quiero cortar a 45 grados. Los catetos proveen una superficie sobre la cual se puede apoyar el costado de la hoja de corte, con la confianza de que el desgaste será lento, permitiendo así usar la herramienta varias veces antes de tener que descartarla o rectificarla. Se usa un cateto u otro, dependiendo de hacia qué dirección va la inclinación del ángulo de 45 grados a cortar.

Gracias a esta herramienta barata y fácil de hacer, pude terminar sin problemas el trabajo que había interrumpido.

The hypotenuse serves as base, projecting downward and thus providing a guide to support against the profile that I want cut at 45 degrees. The legs provide a surface on which to support the side of the cutting blade, with the confidence that the wear will be slow, thus using the tool several times before having to discard or modify it. Use one leg or another, depending on which direction is the tilt angle of 45 degrees to cut.

With this cheap and easy to do tool, I end up with problems that had stopped my working.

Thats what I need tool, perfect !
Glad to be useful, msel! Thanks for comment.
muy buena solucion Osvaldo.<br>Como decimos por aqui...&quot;a grandes males , grandes remedios&quot;.<br><br>un abrazo y me alegro de que halla mas hispano parlantes por aqui.<br>:)
Gracias, djvanbeat!
Esa si que es soldadura de precision, te quedo buenisima!
Gracias, Bruno. La uso mucho, pronto voy a tener que rectificarle la superficie donde apoya el disco de la amoladora. O tal vez me convenga m&aacute;s hacer otra, creo que ser&aacute; m&aacute;s f&aacute;cil.<br> <br> <strong>Thank you, Bruno. I use it a lot, soon I'll have to rectify the surface where it supports the&nbsp;</strong><strong>grinder disc. Or maybe is more appropriate to made another, I think it will be easier.</strong>
You made a speed square. It is tricky to get an accurate square when welding the members. Congratulations. Well done.
Thanks, Phil. Do you think I must (or would) change the title?<br><br>For welding I made another, with two pieces of the same L iron, linked by two 1/2 x 1/8 dipsticks, like open &quot;A&quot; shape.
You do not need to change the title. I do not know what it is called in other countries, but here in the USA we would call it a speed square. They usually come marked with a ruler on one or both of the legs. The hypotenuse is also graduated with lines marking angles so it can be used from the 90 degree corner to mark angles for cutting roof rafters. Cheap speed squares are made of a heavy plastic. I had one of those, but it shattered into many pieces one day when I dropped it on a concrete floor. Better speed squares are made of aluminum. Carpenters carry them on tool belts or in large pockets.<br><br>There is a good feeling about using a square you have made and it is accurate.
If you dropped Rimar's square you'd have to worry about breaking your foot!
No, pfred2, it is not big, it weighs around 200g. Obviously, if you are barefoot, and it drop with an edge tip over your foot, it will pain.
Great Instructable! I am sharing this with my hubby! Tools are expensive. We are remolding so tools are needed. Have a splendorous day!<br>Sunshiine
Glad you like it, Sylvia! <br><br>Here rains, but it is anyway a splendorous day. I reward your good wishes

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