3. Computer controlled cutting¶
This week our main task was to design using parametric tool, such as fusion 360 and cuttle. Last week I tried to use cuttle.xyz to design a parametric box layout, therfore I am to detrmine to expirment with Fusion 360 as parametric design tool. Export the design as .dxf because that can be read by a 2d-machinerry such as laser cutter and Vynl.
Fusion-360¶
First design¶
My idea was to create one piece that have a built in joint something similar to a Lego piece but in 2D. I tried to scale the whole design with parametric measures, height, and width number of joint as the shape change in measurements, material thickness and joint thickness.
Problem 1 - dimesion overload + not parametric¶
Sketch overload dimension, 100 mm in width is not idle for my design. Parameters: The parameters formulas were too much and not well-executed therefore the main important aspect were the joint-thickness and it was not working just one joint change and the rest stay as the initial measurement.
Adjustment 1 - parametric¶
Problem 2 - Check shape in Inkspace + Sketch overload dimension¶
Note that saving as DXF makes the sketch geometry and lines which I used for mirroring for my joint slots which enable me just to put one parametric constrain for the main shape before mirroring rectangular and circular pattern.
Adjustment 2 - overload dimension¶
To overcome the overload I created multiple sketches in the same plane, each sketch is dedicated to specific component.
Sketch 1 – Piece outline¶
Sketch 2 – Vertical joints¶
I used y-plane and x-plane as my mirror axis instead of creating a line.
Sketch 3- Horizontal joints¶
I used x-plane as my mirror axis instead of creating a line.
Inkspace + Parameters¶
Introduction to laser cutting machine¶
Digital Fabrication¶
Digital fabrication refers to the process of using computer-controlled machines to create physical objects from digital files.
Types of Machines¶
Various types of machines are utilized in digital fabrication, including CO2 laser machines, which are commonly used for cutting and engraving materials.
CO2 Laser Machine¶
The CO2 laser machine operates using a focused or non-focused laser beam to cut or engrave materials, utilizing assist gases to enhance the cutting process. It is characterized by minimum waste, high average power, and quick setup, making it efficient for various applications.
Laser Physics¶
Understanding the physics of lasers is crucial, including concepts such as photon flux, energy levels, and the characteristics of the CO2 laser beam. The CO2 laser operates at specific wavelengths (9.6 μm and 10.6 μm) and involves energy transitions that are essential for its functionality.
For more info visit group assigment page¶
Machine Parameters¶
Important parameters for operating a laser cutter include focus, power, speed, kerf, and joint clearance, which must be characterized for effective use. The kerf is defined as the difference between the material thickness and the best fit thickness, which is critical for precision cutting.
File Formats¶
Common file formats used in digital fabrication include Scalable Vector Graphics (SVG) and Drawing Exchange Format (DXF), which are essential for preparing designs for laser cutting.
How to operate laser cutter machine?¶
Open ventilation¶
Switch machine on by the black switch and press the red button in case of fire and use fire extinguisher or blanket.
### Computer connected to the laser machine (import your design)
Placing the design in bed-work and download it to the laser cutter machine.
Check for the file name if downloaded + check spacing of the laser by controlling the ‘Z’ button if there is good space between the working material by having it equal to the Lego piece length + click ‘origin’ to place initial point, then press frame to check the workplace of the cut, if not move it again and change origin the ‘frame’ if it good press ‘green button’ .
Results:¶
First try – 1mm¶
The joint width were too low, the lines of the planes appeared in the piece and the spacing between the slots were not equal in the upper and lower slots. I return back to fusion 360 sketch and fixed the dimensions and increased the joint thickness.
### Second try: 1.25 mm
The axis and center point were shown in the drawing in inkspace I removed them and sent to bready for the cut.
When fitting the design of the joint ends were not easily handled and fragile. I return and had a new design for the end joint by increasing it width. For these type of joint is recommended to make the joint thickness at least as material thickness (1.4 mm) or a little more.
Final try 1.5mm¶
The axis and center point were shown in the drawing but I cleared them before cutting in the laser machine. The final design is just the building block for the final shape were I laser cut multiple piece from the same shape and have a model to present structure stability and joint-fit. The prototype has an issue were the work-bed moved down therefore the cut was not perfect but fit was good, 1.5 mm is a good choice.
Fusion 360 Tutorial: How to create the shape?¶
click here to download .DXF file
click here to download .STL file
Sketch¶
Sketch the general shape dimensions in x-plane because there is no need to rotate later to export the file it will be shown with no issues.
Create the Joint design
Create another sketch on the first drawing plane. (to overcome dimension overload)
After choosing the primary object of the pattern create parametric dimension (Joint_thickness) + when using patter or mirror modifier it highly reccomended to choose the origin planes as the line it reduce unwanted lines showing before cutting.
Constructive Model¶
The final design is just the building block for the final shape were I laser cut multiple piece from the same shape and have a model to present structure stability and joint-fit. The piece can be arranged vertical and horizontally easily but it is not consistent in pattern it not a perfect repetitive building block. I had some difficulties in assembling the pieces. I think further adjustment of the design need to be studied and tried in Fusion 360 assembly before cutting to get a sense of how you can assemble the pieces together.
How to operate vinyl cutter?¶
Choose your desired file¶
Scale + positioning + trace outline¶
Result¶
Choose the vinyl color and machine cutter + place the sticky green matt and place the material in the grid and ensure to tap the vinyl to ensure it is flat + place the mat and working on the white grabber in both sides then click ‘load out mat’.
Trim the border + the remove unwanted material by using tongs + place the desire shape on transparent book wrapper + place on ‘not smooth’ material like paper.
