Third week

Third
class

This February 10th was the Computer-Controlled Cutting and I liked it very much because was the first time that I choose to be a volunteer, it was a short time but I wanted to present my progress, it was a good experience. Inside the class we were able to learn some concepts about CNC machines, they showed us the types of laser cutters and vinyl cutter. Thanks to the classes I receive from the Barcelona lab I was able to learn the operation of many of them and learn about their characteristics.

The Barcelona team is a great working team, Josep, Eduardo, Santi and Xavi are giving us very good support with many softwars so thanks to them I have been able to understand better the necessary programs. ¡Thank you guys!



My first time as a volunteer




10

First Assignment

Grupal Assignment

In order to have access to a laser cutter we had to process a permit to go to the Fab Lab in Lima, this space is inoperative since the beginning of the pandemic in 2020 but we have been able to take out all the machines except the laser cutter due to its size and weight. After a year I have returned to operate a laser machine, it has been very nice to meet again with our old workspace and especially to see again some of the team, I missed this space already!

To start the work we had to have all the necessary protocols both at the entrance of the building and in the space itself, after that we organized the materials to use and checked the machine, some time ago there was an accident due to a bad maneuver but happily it can be used, thanks to my partner we were able to clean and leave the lab ready to create and have fun.😍

Working remotely

Characterize the laser
cutting machine



To begin to operate a machine you have to understand how it works, its features, its parts and especially its limits, I had already handled a laser cutter before but I had never stopped to understand its operating system. This space has allowed me to research and learn more about the concepts of cutting and also explore its capabilities. This system is very interesting because being a precision work it helps a lot to the quality of the cuts and of course with a speed that hardly a human being could replace.

Next I will share some summarized graphics about how a laser cutter works, thanks to the Fab Lat team we had a special session with one of the specialists in Trotec machines, his name is Luis Flores and here we know him as LEFO, we met online with him to have more information and suggestions from him, thank you very much master! 😃



Reencounter at Fab Lab Lima with Stefany and Hayashi.



General concepts


- Laser: A laser (LASER, light amplification by stimulated emission of radiation) is a device that uses an effect of quantum mechanics, induced or stimulated emission, to generate a spatially and temporally coherent beam of light.
- Focus: In geometrical optics a focus is the point where the light rays originating from a point on the observed object converge.
- Vector: In mathematics and physics, a vector is a mathematical entity such as a line or a plane. A vector is represented by a line segment, oriented in three-dimensional Euclidean space.
- DXF: DXF (Drawing Exchange Format) is a file format for computer-aided design drawings, created primarily to enable interoperability between DWG files, used by AutoCAD, and other programs on the market.
- Power: In physics, power (symbol P) is the amount of work done per unit time.
- Speed: Velocity is the vector physical quantity that relates the change of position (or displacement) to time.
- Cutting: Laser cutting is a technique used to cut sheet metal parts characterized in that its energy source is a laser that concentrates light on the work surface.
- Engraving: Engraving is an artistic discipline in which the artist uses different printing techniques, which have in common the drawing of an image on a rigid surface, called matrix, leaving a print that later will house ink and will be transferred by pressure to another surface such as paper or canvas, which allows obtaining several reproductions of the prints.
- Marking: "Laser marking" means marking or labeling parts and materials with a laser beam. In this respect, different procedures are differentiated, such as engraving, removal, discoloration, annealing and foaming. Each of these processes has its own advantages and disadvantages depending on the material and the desired result.

(Source: Wikipedia.com)

Graphic concepts




Position of the laser focus





Laser tube process





Detail of laser cutting



Laser Cutter


Steps to use the machine
- The first step is to have a safe working space, as the laboratory has not been used for a long time we first arranged things and freed the machine from contact with hazardous materials, it was also important to mark the floor because of the distance of use. 👍







- Our machine is the Speedy 100 Trotec Laser and has the following features:

MACHINE SIZE
974 mm width x 765 mm height x 457 mm depth

WORK SPACE
610 x 305 mm

LASER TUBE POWER
12 to 60 W




- Font





- The next step was to calibrate the machine and put our files into the computer. For this we had seen that there was a flaw in the lid, months ago a fire occurred due to a bad maneuver or lack of supervision of the cutting in development, fortunately it is only a superficial damage. 😫








- As a next step we did a test on 4mm cardboard because happily we got an open store that only had that material.





Configure the parameters




First result



- Everything seemed to be fine, however the parameters did not work when we had the larger pieces cut. 😩





The cardboard began to catch fire




Exited burned



- At first we thought that the reason why it was not working was because we got a message about the filter, I remember that the laboratory team told us that it had to be changed some time ago. In the following picture I show the lower part of the machine with the message "change filter". However, we talked to the LEFO specialist and he told us that it could be two things, either the focus is bad or the lens is super dirty and needs cleaning, so far we have concluded that it is the lens, we have done many tests and we have not achieved a good calibration.





- As can be seen in the following photograph, the tests did not change, when we increased the power a little and lowered the speed, fire came out and when we inverted the values, it did not cut very deep.





- Due to the inoperative machine and the short time available in the lab, we were not able to cut on the Trotec Speedy 100 yet, but we had the file of our designs ready as you can see below.





SolidWorks




SolidWorks 3D



- The part can be designed in any program that has 2D/3D capabilities and that exports files in DXF (Drawing Interchange Format) format. We decided to create the laser tester in SolidWorks. While we were working on the design, we notice a problem… For some reason we notice that SolidWorks wasn’t creating the DXF file correctly. We saw a preview of the DXF file that SolidWorks was creating and some vectors were missing. This anomaly didn’t happen with older version of SolidWorks so we assumed it could be a bug exclusive to the 2020 version. The best way to solve this problem was to create a 3D representation so that SolidWorks could have a better idea of what we wanted. After doing this SolidWorks was able to create the DXF file perfectly.





Final design



- Well, it wasn't all bad, we got a laser cutter outside the Fab Lab and were able to test some of our files. It was important to see the difference in behavior of at least two different materials so we chose cardboard and clear acrylic. In order to be able to not only think in flat pieces we were also inspired by the Instructables pieces and generated some variants to test our cuts.





Curved Laser Bent Cardboard - Acrilic




Curved Laser Bent Cardboard



- The parameters we used were:

Cut:
4mm Cardboard: 60 Power, 1 Speed, 1000 PPI
4mm Acrilic: 30 Power, 0,3 Speed, 5000 PPI

Engrave:
4mm Cardboard: 30 Power, 100 Speed, 1000 PPI





Slot spacing




Slot spacing




This is the first experience we had as a team and we will come back to solve the Fab cutter system and also learn about the maintenance and cleaning of a laser cutter.💪

As additional information, after making the cuts we realized that the tolerance had a measurement of 0.15 mm, that is to say that if the original dimension of our drawing is 10 cm, when we cut it we obtain 9.85 cm, this is an important point to consider before making a very precise work. ✋

Special moment


Another thing I got from returning to the Fab Lab was to look at my previous work, when I was doing my educational workshops I was using part formats for the children to build their own creations. 😍 These were a lot of fun for them and simple enough to get them to work on their imagination, so I started using the laser cutter, giving them a purpose to use the parts designed in Rhino. 💪 What I liked most about these formats was that I could make them to any scale, the bigger the kids got the more fun they had. 😃





Pieces designed for my workshops




Pieces designed for my workshops




Pieces designed for my workshops




Workshop in Chorrillos - Lima




Workshop in El Agustino - Lima




Workshop in El Agustino - Lima




Workshop in "International day of girls and women in science"




Workshop in "International day of girls and women in science"





Workshop in Cusco - Perú




Workshop in Cusco - Perú





10

Second Assignment

Individual Assignment
Team LAT

This week we also had the opportunity to learn about the operation of a vinyl cutting machine. Thanks to the Fab Lab Peru team we were able to coordinate access to one of them and take a tour of each of the team's houses. I was the first one to have it and thanks to some tutorials on youtube I was able to learn how to operate it.

First part

Vinil
Cutter


The first challenge was to get a vinyl cutter, thanks to Tio Geny from Fab Lab Peru I managed to get one at home to be able to do my tests. We quickly coordinated and I was able to have the machine shortly after the Wednesday class. Due to the pandemic we can not easily access the Fab Lab labs, so we had to organize ourselves to have the machine at home for each of the Fab Lab Lima team.

This is the first time I was able to operate the vinyl cutter on my own, I had seen it before but never used it, I enjoyed learning how to use it. The cutter I got is the ScanNCut2 CM650W Brother, it has a 12" x 12" work area and a built-in 300 DPI scanner. The material I got was vinyl of different colors so that allowed me to try different shapes and sizes, thanks to persistence I was able to make my first tests.



Receiving the machine at home



Vinil Cutter


Steps to use the machine
- First of all I had to see some tutorial on YouTube, I recommend this vídeo because is the official channel of this machine.
- When I became familiar with the information I started to open the box to see all the components, here are the pictures of what was sent to me.




- To understand the parts of the machine I built this next picture where I put the main parts, it is important to know this before using it.😄





-The next step was to start a test, inside the operation panel you have several alternatives, I chose the one to cut a text, for this example I used the name of my project.🥰





Configure the parameters




To place the material correctly




Initial cutting test




Programming the letters




Vinyl removal




First result



The next day I wanted to do more tests to get to know another type of letters and figures of the machine and I had a big problem. I had considered that I should not move the parameters because they had already worked the day before, however when I did the test with another color of vinyl it came out wrong, the letters had not been well cut and it was very difficult to remove them from the paper. It was frustrating because I could not find the reason, I made some changes in the parameters and it was still wrong.🥵





Difficulty to remove the letters




Imperfect lettering



After several tests I did a review of all the variables to make the vinyl cut because maybe there was something I was forgetting, and so it was, I had noticed all but one; the cutting knife holder! When I checked it had one number less than the previous day, what happened was that the night before when I put it away it had been turned and it was marking the wrong number, this means that the reason why it was not cutting well was that the blade was too high. Fortunately when I went back to the previous number I was able to continue with my other tests, it felt great to find the solution!😃





Working




Exploring




I am happy to solve the challenges




¡Home is the new LAB!



After the wonderfuladventureit was time to continue on the machine route, our team is moving it from house to house to use it so my partner Stefany came to pick it up so we could work on her designs.Task accomplished!😍







Second part

Laser
Cutter

Parametric design has been a very nice challenge, I have been able to explore various tools that I had not used before with this level of optimization. Here I show you a journey between some software like FreeCAD, Fusion 360 and Rhinoceros - Grasshopper. 💪

FreeCAD


Exploring patrametric shapes
- To start exploring parametric shapes I made some figures in FreeCAD with the help of the Spreedsheet command that allows me to generate a table with the parameters I want to place. I made a circle of two different designs and each of them in different files that I will attach for review. I didn't find it too complicated but it does take a little time as you need to generate all the necessary constraints before changing any of the values in the table. 🤗





First circle




Constraints




Spreadsheet




Second circle




Constraints




Spreadsheet


Fusion 360


Exploring patrametric shapes

- I really liked Fusion 360, it is the first time I explore parametric drawing in this program and I did not find it very complicated, it has a logic very similar to FreeCAD but has many more things that make this program more complete, besides the interface is much more friendly, the experience has been good but I needed to go step by step.💪

- First I got a tutorial to understand the logic of parametric shapes, I found this vídeo very helpful to know where the table of values was located and the mathematics that can be built to create relationships between the lines.




First exercise




First exercise


- Thanks to the first exercise I understood the sequence I had to follow to make the drawing I needed for my first parametric part. Although it has the same logic as FreeCAD, Fusion is a bit more complex to handle if you don't know the location of the configurations, happily I was able to quickly solve some complications in the process and this was my result.😃





Configure the parameters




To place the material correctly



- Finally, I have built with greater design complexity these three formats that are parametric to each other.





Rhinoceros - Grasshopper


Exploring patrametric shapes

- I am really impressed 🤩 for having achieved a good result in this program, I knew Rhino and Grasshopper but never put it into practice with such precision, it is definitely a software that requires a lot of patience and above all knowledge for the development of the designs but something that is helping me a lot since the first week is to first view the tutorials that can teach me to handle the commands and recognize the workspace.

- Thanks to the Barcelona team and the master classes prior to the Wednesday classes I was able to do a reminder of the program and thanks to the Fab LAT team we had some sessions to share information and teach each other. Working as a team in this kind of things is very important to be able to optimize the time and resources we have to successfully accomplish the weekly tasks.




Team Barcelona




First practice



Team Latinoamérica




Second practice


-Well, this vídeo tutorial helped me a lot to create a prototype in a fully parametric way, it is interesting because at the beginning it may seem very stressful because there are many configurations but it really solves many things when you achieve it, it is possible to quickly get the perfect replica of a pattern and change any parameter, I really like how it works. very helpful to know where the table of values was located and the mathematics that can be built to create relationships between the lines.




Origin - Curve




Patterns - slots




While watching the Lab session




Simulation



Parametric construction kit


Laser cutting

- After all the adventure and challenges of not having a machine available I managed to make some cuts in two materials, cardboard and acrylic, the pieces were built in Rhino and Grasshopper, I really liked designing parametrically to cut, I had never done it before.





Digital design




Parametric design




Cardboard and acrylic designs




Cardboard and acrylic designs




Cardboard and acrylic designs




Cardboard and acrylic designs


Download the files here


GrupalRhino
IndividualRhino
FreeCAD1
FreeCAD2
Fusion360