Week 3. Computer-Controlled Cutting
Lets get practical!!
Group assignment:
Do your lab's safety training
Characterize your lasercutter's focus, power, speed, rate, kerf, joint clearance and types.
Document your work to the group work page and reflect on your individual page what you learned.
Individual assignments:
Design, lasercut, and document a parametric construction kit, accounting for the lasercutter kerf, which can be assembled in multiple ways.
Cut something on the vinyl cutter.
Learning outcomes
Demonstrate and describe parametric 2D modelling processes.
Identify and explain processes involved in using the laser cutter.
Develop, evaluate and construct a parametric construction kit.
Parametric construction kit and Laser Cutting
I decided to try rhino and grasshopper to create a parametric model for for this Week 3 Assignment.
I want to make something very simple that could be easily modified to create a range to geometric shapes to use as a connectable set of shapes.
For this we used the polygon component in grasshopper.
Number sliders are used to set the radius of the polygon in the component this controls the overall size.
To create a slider in grasshopper double click canvas type 5 < 24 < 100 this creates a slider going from 5 - 100 and set at 24.
With this we know of the basic shape of our part we can adjust the number of sides on the polygon and the overall size with the sliders.
The outputs of the polygon component is polygon (represented as one single curve) and length.
To highlight this, I have added a curve component and connected the polygon output from the polygon component to it.
We need to add slots to do this have to identify the midpoint of each curve that makes up to the polygon. To break the curve into individual segments, use “explode”. We can then analyse these curves to extract the midpoint and if we want to adjust this later, we can use "point on curve".
Use “Area” component to find the Central point on the polygon. This will be used to create the slot line from the midpoint to the centre point.
User “Vector 2PT” and “Line SDL” connect the midpoint and centre point to vector 2 point.
Connect the “Point on Curve” to the start point of “Line SDL”. Add the vector to the direction. A number slider to specify the length of this line.
Double click the slider to change the name and, in this case slot length. We can also adjust things like min, max of the numeric domain and the set point. And set the slider accuracy and decimals or whole numbers.
Offset this line each direction to create the slot, this will be half the material thickness in each direction.
Close the curve to a rectangle using the "end points" and the "line" component.
These 4 lines the 2x "offset curve" and 2x "line" components can be merged to create one closed curve using the "join" component.
These closed rectangles need to be removed from the original shape. Use “Region Difference” component to do this. Connect the polygon curve we created at the start of the definition and the “joined curve” component just created.
This should create one flat curve. You will need to flatten the curves coming into join curve to you can zoom in right click on the node and select flatten.
Add the curve component to tidy up the definition. Then we can bake this. But first we beed to add Kerf allowance.
We can select all components except the last curve component right click on the canvas and click “preview off” .
This gives us a clean uninterrupted view of the outline curve. Which should be one closed curve planer curve. (add a “panel” component to see what is being output from the curve component or any component for that matter just connect the node you want information from.)
We can add a kerf with slider that and a subtraction component Add the material thickness slider to A on subtraction and the Kerf With slider to B and then connect this to where material thickness was before that.
Some cut parts assembled
Vinal Cutting
I created a document in Adobe Illustrator to size I wanted. This contained text and a background. The intention was to have square with the fab academy mantra “if it’s not documented it didn’t happen” for my Fab Academy note book.
We need to outline the text, this will allow us to move the document to another computer that might not have the font. To do this we go >object >expand in Illustrator.
Ensure object and fill are selected in the dialogue box. Click OK.
You should see the text outlined like this when selected.
We are now ready to export we can box select what we need to export >File >Export Selection
In the dialogue box we can rename the “Asset 2” in my case to the desired file name.
We can also select where we want the exported file to be saved. Ensure you select SVG and the file format, it is also possible to select other formats if you need them at this stage it should export them all at this stage. I just need SVG format.
We can now take this to the computer connected to the vinal cutter. In the Creative Spark Fab Lab that computer is running Inkscape which is why we exported in SVG. FYI -It is possible to cut from illustrator if Roland cut studio plugin in installed.
Time to set up to vinal cutter – in this case it’s the Roland GS2 -24. We are going to use a piece to cut the part from. In the cutter menu select piece and press enter.
The vinal cutter will measure the piece size.
We will use this dimension to set the artboard size in Inkscape.
Set the Force – from past experience using this material and blade type it should be set to 90gf.
Import the document into Inkscape. Set the art board size to the same as what was measured on the vinal cutter
Ungroup the parts that were imported.
Select all and make sure the fill is set to none and the stroke is solid colour. We also need to make sure the stroke size is set to hairline.
Place the parts on the art board where you would like them printed in the vinal. We can now >file> print
Print to the Roland GS2-24 Enter the part size again when instructed and press go.
The part should now cut.
I cut the text and the rounded square together
I also cut rounded square on its own in white vinal for the background.
Time to weed out the text - this is. Delicate process we will need scalpel/craft knife and tweezers don’t pull directly up sheer the vinal back at an angle. Some parts like the dots for the eyes might need to be placed back in place. Take your time!!
Use transfer tape on top of the vinal to allow us to place it where needed. Use plenty of (reasonable) force when attaching using a spatula.
Prepare the surface to accept the vial – I cleaned the notebook surface using Isopropanol and allowed it to dry.
I then applied the white background. Apply from one direction using the spatula to press down avoiding any bubbles – again use force
Next I aligned the text – notice how I used the rounded rectangle as alignment aids on the transfer tape. I only applied force with the spatula over the text
And there we have it … the fab academy mantra for the rest of fab academy!!
Learning Outcomes
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