3. Computer controlled cutting¶
This Weeks’ Task¶
- Group assignment
1- characterize your lasercutter’s focus, power, speed, rate, kerf, and joint clearance
2- document your work (individually or in group)
- Individual assignments
1- Design, lasercut, and document a parametric press-fit construction kit, which can be assembled in multiple ways. Account for the lasercutter kerf.
2- cut something on the vinylcutter
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Lets Design!¶
This week’s assignment is fun, as we had to use machines in order to create any design that we desire. “Well, it should be 2D design” So lets start with:
Vinyl cutter¶
vinyl cutters use a blade to cut a design into certain materials.
The machine used in our fablab is the cricut explore family which comes with a software that you have to install to edit the images that you want to cut.
This is the design space for the software
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Steps on how to use the cricut explore family machine
1- Download any image you want to have as a design. I went for an anime called Kakashi.
2- Upload the image in the software by clicking on UPLOAD, UPLOAD IMAGE.
3- Choose your desired complexity of your design. I preferred complex for maximum details.
4- Then, you select the areas in the image you want to remove in order to create mass and void shape.
5- This is how it turned after removing all the shapes in order to create voids.
6- After clicking continue to proceed with the design, I selected the Upload type to cut image.
7- The machine is cutting the sticker.
8-This is how it looks after the cutting.
9- After cutting the design, I took out all the white spots to create a contrast, hence, showing the design.
10- Finally, This is how it looked on a monitor. Love it!
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Laser cutter¶
Laser cutting is a method of cutting to design a given material using a software’s to guide it by laser. There are three main types of lasers used in the industry: CO2 lasers Nd and Nd-YAG.
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CO2 laser cutter¶
In our Fab lab, we use the
CO 2 machine which involves firing a laser which cuts by melting, burning or vaporizing materials. It can cut through almost everything, only metals and hard materials. It can however engrave them.
This is the machine.
- All laser cutting machines work the same way by using x axis, y axis and z axis to move, cut and engrave the material.
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It includes a CO2 Laser tube which acts as a beam filled with CO2= 10 ,N2= 10 and HE= 80. The laser beam is directed to the laser head and focus on the material surface.
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There are control motors that moves the laser head to cut and engrave the shape on the material.
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When the laser hits the material, the heated part will melt, burn or vaporize in which it will define the shape.
There are preferable Settings for each material that our instructor has showed us for both engraving a material and cutting it:
Keeping in mind the thickness limitations:
Laser cutting - Group assignment¶
In our gorup assignment, We ran some tests to see the speed rate and power in order to ingrave or/and cut materials.
So first, we Used the RDworks software to as it is the software that the laser cutter recongnize.
Hint: you may use any software to design as long as you can save it as DXF and open it in RDworks software or other formats that the software recongnizes.
We created a design that the speed increases horizontally while the power changes virtically. So each square will have its own settings.
To change the settings of the squares, we gave each a color, then from the right hand side pannel, we click on the color that we want to change the settings of, and change it.
After finishing all the settings and choose the material desired. We placed the material sheet in the cutting area and started the operation.
This is how it looks with the ingravings. As you can clearly notice, onces we increase the power and have low speed, the machine will ingrave/ cut the material in more presized way and as we accelerate the speed, it will show less details with the high power and vise versa.
Keep in mind: It is always recommended to create a test design before actually cutting the whole design. This is to get the desired outcome.
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Design and Lasercut a parametric press-fit construction kit - Individual assignment¶
I started brainstorming to find a suitable design to create a parametric press fit kit. I was inspired to create a candle holder that represent the sea waves as both of the elements (sea waves and candles) bring calmness and soothing effects. So let me walk you through my steps:
To design the object we need to draw three main shapes:
One small circle.
One big circle.
10 Curved shapes to be connected to the circular shapes.
The design is made for a 3mm thickness material.
1- I used Autocad in order to design the project.
Note: Same steps have been used from week 2, in order to create the design.
2- After drawing the design. I wanted to represent the waves in a more dynamic way. So I took half of the pieces and played with the outer curves.
The red curved shapes are the old design and the blacks are the modified ones.
Cutting the design
1- I uploaded the design in RDworks software.
2- We added the material sheet and fixed the focus.
3- We started cutting the shapes with a mistake of not creating a test design first.
4- So what happed is the joints were big and not holding onto the circle, which is wierd as I made them smaller than the thickness of the material.
5- So we ran a quick shape test by making different joint thicknesses, and It appeared like all the sizes are the same even the really small ones.
6- So what I noticed that the power was high and it eats the material a little more than what I spicified. So I lowered the power and started cutting.
7- It fitted perfectly!
Design and Lasercut a parametric press-fit construction kit - More¶
I wanted to experement more in laser cutting as I was really loving it. Because the material of the old design did not satisfy me (cardboard) I wanted to experement on acrylic.
So I went and cut the design on acrylic. But a problem happened where the laser is not cutting all through the acrylic! which is weird because the power was 50 and speed is 30.
So I went to higher the power and it was cutting perfectly when I did a test cut.
So I started to cut the whole design on the acrylic and it was looking good. Only that when it reached almost the end, the acrylic started to bend and the whole design was bending and it ate a lot of the acrylic than the required.
So I did another test to test the perfect speed and power to cut the design. and surprisingly, it cut all the shapes with different speed and power.
So I went and chose the min power I had form the test which is 60 and tried to cut the design again. And guess what, It DID NOT CUT ALL THROUGH !!!
So I thought that the problem was from the lenses that reflect the laser which should be cleaned. So for now, I did another round on the design to cut it and FINALLY. It did cut.
This is the final design. A prototype for a small vase/ curved shelves
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Design Files¶
Here is the design files to download