I remember that warning adults used to tell me when I was still a kid about not playing with fire, and now I think it's so much fun to use a laser machine to cut and make prototypes come true, it's like "playing" with fire but for a thousand times. This week the #academychallenge is to learn all about computer controlled cutting and use the laser cutting machine and the vinyl cutting machine.
Both work under the same logic, we move the blade or the head of the machine on the x,y (z) axes which allows us to move along the entire path we want to cut or segment. Of course, as with any manufacturing process, it is preceded by a design process that must be carried out taking into account certain considerations for the cutting process to be successful.
📆14th April
This week's group assignment is about learning, testing and verifying all the processes involved in computer-controlled cutting, for example, studying the parameters of the laser cutter or knowing how to set up our vector files so that they are ready for cutting. In this new round, with Fab Lab ESAN, we will look at the Trotec cutter and its functionalities.
Our node has the speedy 400 version of C02 and can cut/engrave the following materials:
Materials that cannot be cut:
The parameters are those data that the machine needs to recognize when we send our files, these must be the correct ones to generate clean cuts and/or engraved correctly.
Technical ranges of Trotec Speedy 400It is very important to make previous tests before sending our final cut since what we want is to make sure that our configuration will be the optimal one. We also do this as a precaution, if we choose the wrong parameters we could cause accidents or on the contrary not succeed with the execution of our work. Here we share an example, these are the steps we follow to generate cuts in a 3mm cardboard in 30x60cm format.
Software JobControl
This program allows us to control our laser machine, it supports designs drawn in programs such as CorelDraw, Photoshop, AutoCAD, etc. Its operation is quite simple and fast. Below we briefly share the steps we followed to install this program on our PC.
RGB Color
In JobControl, Trotec's software, we have 16 default colors that are the only ones we can use in our vector designs. That's why our team looked up the RGB code for each one and created a template with these colors to have on hand, the template allows us to assign the colors to the vectors of our designs if we want to configure them at the time of cutting with the laser machine.
Operation
Most basic machine parts:
Lens and mirror
In principle the beam leaves the laser tube and travels straight to the focusing lens, bounces off the center of the mirrors and passes through the center of the lens. Lenses are used to focus the laser beam in CO2 laser machines.
Lens placement
Design considerations for Test or any laser cutting
We in the group realized that when you design drawings or test catalogs you have to be very careful. It won't do any good to do a kerf test, or a fit test if you draw the measurements wrong or make a mistake in the scale, because when you cut it and go to verify the measurements with your calibration tool, you will not get the measurements you expected or you will never know the true variation of measurements between the file and the reality, because the file never had the measurements well done.
Therefore, the following is recommended:
A_If parametric software such as SolidWorks or Fusion 360 is used:
You can restrict the measurements so you can easily modify them if you made a mistake. And by clicking on each part you can know the measures you have placed.
List of parameters used
List of parameters used
List of parameters used
Test encastre-corte. Comb.
MDF
List of parameters used
List of parameters used
List of parameters used
List of parameters used
List of parameters used
List of parameters used
It has been a journey to complete this assignment because in the middle of a work week my laptop burned up when I connected it to the laser machine. A complete mystery. My advice is to check that your lab has a good electrical system to avoid power surges.
As a first step, you should always calibrate the laser focus with the tool that comes with the laser cutter. Otherwise, the whole exercise could be inefficient.
I designed parametric parts with Rhinocecros and Grasshopper. In this exercise I parameterized the insets and also the number of sides of the geometries, as well as the number of geometries in each row and column. You can have triangles, hexagons, octagons, etc.
After trying to cut for the first time, it was possible to obtain the cutting of the parametric pieces in cardboard and gray PET material, in order to obtain a set of assemblable pieces. The parameters used were:
Cardboard parametersThanks to the Fab Lab team, each member was able to take the vinyl cutter home during the pandemic and confinement. We were able to practice with it in peace and quiet.
As a first step I made a test of a small rectangle. And I activated the machine in cutting mode. Previously it was necessary to check the blade accessory to make sure it cut correctly. The first test was successful.
The vinyl cutter works on the y, x, and y axes and with the correct blade can cut designs accurately. It is important that the vinyl to be cut is securely attached to the plate where it is adhered for cutting.
- Both the laser cutter and the vinyl cutter are computerized numerical control machines, so they must be designed precisely for optimal cutting.
- Also, always be careful with the electrical system where you are going to connect the laser cutter, to avoid power surges. Finally, the laser cutter emits emissions, while the vinyl cutter does not. The space should always be properly ventilated.
- It is not advisable to cut materials containing PVC, due to the toxic emissions it emits when cut.
- Due to the pandemic, I was only able to have the vinyl cutter for a short time, I would have loved to cut more designs.
- Parametric design and grasshopper are highly powerful 3D digital design tools. For this exercise they were excellent allies.