MJ2 Artesanos

Year: 2013

Leonardo’s freestanding bridge

Here’s a quick craft to spend the afternoon and if you Seize children to enjoy learning, there is no question of giving them a kind of strength of materials …. but something remains.

Browsing as usual on the internet, and as usual, looking for something else, I went to give this blog a technology teacher:

http://pelandintecno.blogspot.com.es/2013/01/puente-autoportante-de-leonardo-da.html

Our compliments to the author of this blog, I wish all teachers (thankfully we know many cases) cared so much for making children understand the concepts of such an interesting way.

The bridge in question designed by Leonardo da Vinci, appears in Codex Atlanticus, Volume 1. pages 69r and 71v. (1483 – 1518 Ambrosian library in Milan). It is a bridge designed for war, lightweight, whose main characteristic is that it holds only for the charge distribution sleepers enter ingeniously fitted together, without ties or nails.

This is the picture that has come down to us:

Here’s a drawing with the necessary parts:

I used two strips of circular section 12 and 6 mm in diameter. To make the holes I used the circular saw blade placing 6 mm space that it might be necessary for the “rungs” without cutting the whole piece.

Although it’s relatively simple, in the case of using all the slats cylindrical We must be careful to cut at diametrically opposite points, because if we deviate, the pieces will not fit, so it would be easier to start with the pieces that make of “legs” are of square section. They can be cut with hacksaw and retouch them with a file.
In my case I used the circular machine, to make it faster

Here a sketch of the assembly:

I have to apologize for the quality of the photos, at first I did this as a personal entertainment and not properly documented.

And the bridge assembled:

Later I decided to make it with all the pieces of the same diameter because it seemed a more elegant solution. In this case we can not make the cuts deep enough to fit the whole cross parts, only a half, so that besides being a clever example of load distribution becomes a fun pastime when mounting, as a house of cards.

Leonardo designed the bridge for war, as it was easy to assemble and take advantage of the surprise element. For us it is a toy that helps us to exercise our manual skills and our patience.

A friend who wanted to do it with her toddler that is too young to use saws (apart from that we don’t have wooden sticks at home every day), She wondered if we could make it with soda straws. So here you see that its possible, so there is no excuse for making it and have a fun time. (I made Cuts to fit the “steps” with scissors and V-shaped).

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19 August, 2013
Custom railway stock cars.

Today I will talk about our time like model makers, but this time in the second stage, the railway modellers in Trenes y Maquetas SL (TREYMA). Between model and model, when there was not a large workload, we searched a way to solve the problems we have had in the last model made or how to optimize the way we do it.

Nasa STS

The acquisition of new machines also made us having to become familiar with them and learn their operation to extract all the performance possible. Well, if we add some extra time, problem solving and the new machine, the result is the customization of wagons, locomotives, etc..

One day, we were commissioned to make a model that, although it was not large in size, it required many repetitions and it had stickers that needed to be cut. Hence we decided to buy a vinyl cutter.

The plotter we bought was Secabo C30 III, which had a laser positioning system, which allows you, once printed whatever you want to cut in the printer, place it for cutting in the plotter, something more than useful when printing and cut decals.

Star Wars

One problem that most bothered me about the theme of the decals was the decals with white background, which were somewhat thicker than the clear ones, and once placed they let see white edges. Also if they were placed somewhere with a dark background it showed a dark shadow. Well, the solution to this problem was to cut the shape of the decal in a vinyl mask, paint the background in white and place there a transparent decal, the result was more than acceptable, it was almost perfect.

As well as model shop, TREYMA was model train store, and we had H0 scale wagons with which we could test new techniques for painting and labeling of future models.

Thor

During the post have you seen pictures of some of our customizations. Clicking here you have more photos.

9 July, 2013
How to etch brass. Kit’s collar. (Charmed)

We love it when someone reads our blog and asks us if we could do
something that we hadn’t thought. When this is the case and its
something within our capabilities, we start to investigate very soon.

It’s more fun the less we know about the technique that we will need. So
whatever the final result is, and regardlsee the potential client likes
it or not, we will learn something new, and this is the case that I’m
writing today.

One day we received a request asking us if we could make the pendant of
Kit, the Charmed series cat. After a quick search on google we saw it
was this:

Let’s go on. We got some brass and investigate how we could record it.
It is common for artists to use nitric acid (lowered) but we preferred
to opt for the ferric chloride, because it emits no fumes and is not a
hazardous substance. As I’m not the appropriate person to give chemistry
lessons, this is what Wikipedia tells us about it:

“In industrial application, iron(III) chloride is used in sewage
treatment and drinking water production. In this application, FeCl3 in
slightly basic water reacts with the hydroxide ion to form a floc of
iron(III) hydroxide, or more precisely formulated as FeO(OH)-, that can
remove suspended materials.

It is also used as a leaching agent in chloride hydrometallurgy, for
example in the production of Si from FeSi. (Silgrain process)
Another important application of iron(III) chloride is etching copper in
two-step redox reaction to copper(I) chloride and then to copper(II)
chloride in the production of printed circuit boards. “

Ours comes from an electronics store because, as we have seen, it’s used
to make printed circuit boards.

With no references to the amount, we did it as many times …at a guess. For the amount of water you see in the picture above we use 2 full tablespoons. This post is pending to update with better information if we make further testings.

We recommend using warm water to promote the reaction.

The resulting liquid can be reused, but every time we use it will run worse.

We prepare the brass only cleaning the surface, because it was an old plate, very dirty, and we need a fairly clean one to stick the mask.
As you have read in olther posts,we have a vinyl cutter, so once more we
used it to cut the masks we previously developed (vectorized so that the machine can cut, not just an image).

These masks are those that avoid the corrosion it in the covered area.

There are several methods to do this, from the most complex using
photosensitive material, to the simplest one, drawing the part that we do not want to record with a permanent marker.

The important thing here is a very good sticking of the mask in brass,without bubbles, which can allow the liquid to enter. Also, the more time is immersed, and deepen the brand, will be easier than vinyl starts to peel. Although the photo does not show it, the plate is also covered on the bottom to avoid corrosion on both sides. It’s up to the piece we’re doing and what you want to achieve.

We submerge the board in the solution that we have prepared with hot water, and if possible, to help the process we will move the container creating “waves” to clean the excess brass. We did this during the first few minutes but then we left it about an hour to continue working by itself.

This was the result after removing the mask, and after cleaning with metal polish:

After cutting the silhouette with an adequate metal cutting blade in the drill/multitool, and much patience, polish it with the right accessories for that tool (polish paste and felt tip).

As the drawing is well marked, it’s easy to paint it and remove the excess of paint from the polished surface.

We recommend to varnish the surface, because the brass gets really bad looking with time.

Another option we have, if we only want to shade the previously polished
metal, is doing it by hand with a sponge, here’s a summary:

The next thing we will have to prove is make fretwork drawings. Soon we will let you know.

Meanwhile, if you like this pendant for your cute kitten, you can purchase it here.

22 May, 2013