## Tomato close-up

A beautiful design. A tomato.

There is a lot one can imagine that can happen with a tomato. We can eat it using it to prepare a delicious meal or we can throw it as what happens in Spain on a special event “the tomatina” festival. Here the tomato is munition and we all are the targets. Basically a tomato splat party but on a huge village scale. Now more seriously dropping a tomato will yield an impact test, more known as a drop test. But how could I model this explicit behavior? Looks like an interesting subject, a drop test on a open source application. No LS-Dyna.

Also the drop test will destroy the tomato a a deformable body. These look like interesting subjects for future discussion.

## Brompton bike front connector

This front luggage connector in my bike is giving me ideas… GoPro + Printing machine + Simulation = Something fun to do…

## Flower hugging the sun

Was strolling about my garden and found a wonderful flower. It looked like it was hugging the sun, trying to reach it pushing the lower petals down and the pulling the fluffy pink part up. So beautiful…

## Line wheel

I just love this photo a simple static problem an object mass supported by a table. The most simple structural problem I can imagine with added drama of a close up and incredible lighting.

## The measuring scale

Units play a major role on any simulation software. What are units? Which units are present in specific physics problems and the various types of units that exist for the same physics are a small list of this world. Some times units can be a big headache when we want to send data from one system to another. A good example where I have struggled with this was in combining Ansys with LS-Dyna; fortunately today interchanging k files is a breeze but this was not so in the past.

## The peach close-up

Learning bit of photography gave me more sensitivity about what my eyes are seeing. The way light touches objects, involving them, bouncing back shedding a shadow giving texture and form. Is a illusion? Maybe yes. But still lighting is a pathway to our senses and mood expression. I know there are out there rendering software that intends to simulate lighting effects but maybe still lacks the warmth real light gives to photography.

## Vespa Brakes

The vespa breaking system, it definitly isn’t a disk brake, they are a drum brake system common at this model launch date. A steel wire plays an important role in the braking system. It reminds me of my V-Brake bike, good old technology.

See here for a simple description of the common braking systems available and how it is inside. http://www.levintirecenter.com/types-of-brakes.html

## Making drawings with text

The traditional approach of making a drawing goes back to when we discovered we could use our hands to draw. A direct link from our brain to a canvas through a rock, pen, finger or what ever can make drawing.

This is an analog approach since no drawing will be the same when we attempt to reproduce it again using the same method to create it.

There is however a way to perform an exact copy of the drawing and the drawing generation procedure. It requires the combination of programming and the notion of vector drawing. Basically we use math to describe nodes, lines, surfaces and what not.

Latex and the Tikz package help out in this task.

A good online Latex compiler can be found here: https://tex.mendelu.cz/en/

So what’s this all supposed be? Latex, Tikz, compile, text.

Latex is a sort of compiler, it reads text that are commands, normal text, … and generates a document in pdf. Tikz is a package add-on that connected to Latex allows it to understand drawing like commands.

Code to paste to the online compiler is from http://www.texample.net/tikz/examples/3d-cone/:

% 3D Cone
% Author: Gene Ressler. Adapted to TikZ by Kjell Magne Fauske.
% See http://www.frontiernet.net/~eugene.ressler/ for more details.
\documentclass{article}
\usepackage{tikz}
\begin{document}
\pagestyle{empty}

% The following code is generated by Sketch. I have edited it a bit
% to make it easier to read.
\begin{tikzpicture}[join=round]
\tikzstyle{conefill} = [fill=blue!20,fill opacity=0.8]
\tikzstyle{ann} = [fill=white,font=\footnotesize,inner sep=1pt]
\tikzstyle{ghostfill} = [fill=white]
\tikzstyle{ghostdraw} = [draw=black!50]
\filldraw[conefill](-.775,1.922)--(-1.162,.283)--(-.274,.5)
--(-.183,2.067)--cycle;
\filldraw[conefill](-.183,2.067)--(-.274,.5)--(.775,.424)
--(.516,2.016)--cycle;
\filldraw[conefill](.516,2.016)--(.775,.424)--(1.369,.1)
--(.913,1.8)--cycle;
\filldraw[conefill](-.913,1.667)--(-1.369,-.1)--(-1.162,.283)
--(-.775,1.922)--cycle;
\draw(1.461,.107)--(1.734,.127);
\draw[arrows=<->](1.643,1.853)--(1.643,.12);
\filldraw[conefill](.913,1.8)--(1.369,.1)--(1.162,-.283)
--(.775,1.545)--cycle;
\draw[arrows=->,line width=.4pt](.274,-.5)--(0,0)--(0,2.86);
\draw[arrows=-,line width=.4pt](0,0)--(-1.369,-.1);
\draw[arrows=->,line width=.4pt](-1.369,-.1)--(-2.1,-.153);
\filldraw[conefill](-.516,1.45)--(-.775,-.424)--(-1.369,-.1)
--(-.913,1.667)--cycle;
\draw(-1.369,.073)--(-1.369,2.76);
\draw(1.004,1.807)--(1.734,1.86);
\filldraw[conefill](.775,1.545)--(1.162,-.283)--(.274,-.5)
--(.183,1.4)--cycle;
\draw[arrows=<->](0,2.34)--(-.913,2.273);
\draw(-.913,1.84)--(-.913,2.447);
\draw[arrows=<->](0,2.687)--(-1.369,2.587);
\filldraw[conefill](.183,1.4)--(.274,-.5)--(-.775,-.424)
--(-.516,1.45)--cycle;
\draw[arrows=<-,line width=.4pt](.42,-.767)--(.274,-.5);
\node[ann] at (-.456,2.307) {$r_0$};
\node[ann] at (-.685,2.637) {$r_1$};
\node[ann] at (1.643,.987) {$h$};
\path (.42,-.767) node[below] {$x$}
(0,2.86) node[above] {$y$}
(-2.1,-.153) node[left] {$z$};
% Second version of the cone
\begin{scope}[xshift=3.5cm]
\filldraw[ghostdraw,ghostfill](-.775,1.922)--(-1.162,.283)--(-.274,.5)
--(-.183,2.067)--cycle;
\filldraw[ghostdraw,ghostfill](-.183,2.067)--(-.274,.5)--(.775,.424)
--(.516,2.016)--cycle;
\filldraw[ghostdraw,ghostfill](.516,2.016)--(.775,.424)--(1.369,.1)
--(.913,1.8)--cycle;
\filldraw[ghostdraw,ghostfill](-.913,1.667)--(-1.369,-.1)--(-1.162,.283)
--(-.775,1.922)--cycle;
\filldraw[ghostdraw,ghostfill](.913,1.8)--(1.369,.1)--(1.162,-.283)
--(.775,1.545)--cycle;
\filldraw[ghostdraw,ghostfill](-.516,1.45)--(-.775,-.424)--(-1.369,-.1)
--(-.913,1.667)--cycle;
\filldraw[ghostdraw,ghostfill](.775,1.545)--(1.162,-.283)--(.274,-.5)
--(.183,1.4)--cycle;
\filldraw[fill=red,fill opacity=0.5](-.516,1.45)--(-.775,-.424)--(.274,-.5)
--(.183,1.4)--cycle;
\fill(-.775,-.424) circle (2pt);
\fill(.274,-.5) circle (2pt);
\fill(-.516,1.45) circle (2pt);
\fill(.183,1.4) circle (2pt);
\path[font=\footnotesize]
(.913,1.8) node[right] {$i\hbox{$=$}0$}
(1.369,.1) node[right] {$i\hbox{$=$}1$};
\path[font=\footnotesize]
(-.645,.513) node[left] {$j$}
(.228,.45) node[right] {$j\hbox{$+$}1$};
\draw (-.209,.482)+(-60:.25) [yscale=1.3,->] arc(-60:240:.25);
\fill[black,font=\footnotesize]
(-.516,1.45) node [above] {$P_{00}$}
(-.775,-.424) node [below] {$P_{10}$}
(.183,1.4) node [above] {$P_{01}$}
(.274,-.5) node [below] {$P_{11}$};
\end{scope}
\end{tikzpicture}

\end{document}

I used this code since it was available online to show that you can search the web find the image you desire and get the code, from there you can generate a pdf or even export to svg. You can even pick the code and adapt it to your needs.

Now you can start making your own images with just a note pad! So let’s star drawing… To start go here to find more examples:

http://texample.net/tikz/examples/tag/graphs/

To make the svg file import the generated pdf to Inkscape.

## Vespa Buzer

Strange sets of screws here a mixture of Slotted and Philips screw head, probably not original. This buzzer cover with the screws pressures the metal body to stay fixed. The design issue here is that they need to generate a thread on the bike metal body.