Anna Aflalo

Fab Academy 2015 | Wgtn

WEEK 3 | Computer-controlled Cutting

-- Laser Cutter assignment --











This week assignment helped me a lot with my final project. Children will connect 2D modules to create 3D shapes. I've already made 2 different shapes. I will probably create new ones by playing with size and polygons. Copper tape with conductive adhesive (vinyl cutter) and LEDs will be integrated into the 2D modules.
Before drawing the shapes on Illustrator, I checked if the size of the slots were tight enough. Thanks to the tests made for the cardboard stool (below), it fits correctly. I've started Grasshopper tutorials but I cannot make parametric shapes right now. Now I can sketch and cut my triangles. I play with the shapes to create different 3D shapes. To make the game even more complicated, I've tried to design a 3D piece. I made holes 50% of the height on one side and I plugged 2 pieces together. It would have been much easier to have parametric shapes.

I've cut 3mm cardboard this week. This is the parameters I used :
Slots size : width=2.3mm
Laser cutter parameters : RED=rgb(255,0,0) : POWER= 40%, SPEED= 12%, PPI= 250.
Those parameters were already programmed on the computer and worked very well. On the other hand I've tried to raster and it wasn't a success. On this picture you can see the different test that I've made. I've increased the power until the laser get through the first layer of cardboard. Values tested : 12% > 20% > 25% > 30% > 35% > 40% > 37% > 39%. I've been changed the value while the laser cutter was rastering (Settings > Black > Power > Apply > OK).

Here, download the press-fit file.
Rhino & Grasshopper - Round 1


To create a solid on Rhino from an Illustrator file:
1. Export your Illustrator file as ".dwg" and import it on Rhino.
2. Hold the button: "surface from 3 to 4 corner points", click on "surface from planar curves" and select your shape.
3. Now that your surface is created, remove the curves.
4. Select the function "extrude face" to create the solid (I use the command: 3mm).
First try : how to create parametric shapes with Grasshopper
I start by watching few tutorials online. Grasshopper helps designing algorithms on Rhino. I discover some functions and I start to understand the logic.
Now it's time to try to make my press-fit kit pieces parametric. Not an easy task! I start with the imported Illustrator file. It takes a while before I understand that I need to "explode" my drawing to select the curves that I want to manage from Grasshopper. Once I "explode" my drawing, I select "curve" in the "geometric tab". But I can't change the parameters from the box that appears on the canvas. I double click on the screen, tap "curve" and select the other box called "curve". I try to do the same for the lines but I can not select the lines directly. I have to create points on Rhino. On Osnap tab, I select "intersection". It makes it easier to create points on my drawing. Then I create 3 different "line" box by double clicking on the canvas. To be continued...
Laser Cutting - Lets make a stool
I begin by drawing my idea : a stool with rabbit ears. It's quite complicated to scale each part of the object on a piece of paper. I decide to make a rapid prototype and I cut a piece of cardboard with scissors. Now I have a better idea of the size of each piece.
As a first step I need to design and test the joints. For that purpose I use Illustrator and start by drawing notches with the following size : width=6mm ("plug" width) height=3mm (cardboard thickness). I print it on the laser cutter. Craig helps me to initialize the machine. Here are the steps that I have to remember:
1. Adjust the "waffle" grid
2. Select where to print the drawing on the Illustrator template
3. Check the color and the size of the lines : vector cutting : color=rgb(255,0,0) | stroke=0.1pt
4. Ungroup and join : my vectors were grouped, I had to ungroup and join my shapes (use : cmd+j and the white arrow). Apparently some laser cutter don't deal well with Illustrator groups.
5. And print > setup > preferences > look after the file related to the material you cut. I'm using a 3mm thick cardboard.
6. Check how long the cutting takes on the laser cutter software (if something looks wrong, have a look once again the Illustrator file).
7.Turn on the extraction.
8. Start cutting!
I can test my first joints, the holes are way too big. I change my file and test the following sizes :
width=5mm; height=2mm and width=5.3mm; height=2.3mm. My joints are now working.
Now that my joints are doing well, I can use Illustrator to draw all the pieces of the stool and I cut the first version. I'm not satisfied mostly because of the legs. I go back on Illustrator. The second version is better but I still need to reinforce the legs, I think about adding a piece of cardboard to make the legs stick together.

Here, download the stool file.
Vinyl Cutting
Let's decorate our Compost Lab with green stickers! I use Illustrator to realize my drawings. I select some logos from TheNounProject website and I import the .png files on my template. To obtain drawings I can print on the Vinyl Cutter, I have to convert my images into vectors:
1: I adjust the rocket size that suits me. In order to keep the proportions, I press the shift button at the same time.
2: I select Image Trace in the Object tab and I press the Black and white logo option. Now, I have a quick creation of vectors.
3: to get the optimal amount of vector points, I press the Expand command.
4: I use the Direct Selection Tool (white arrow) to remove unnecessary points.
5: with my white arrow, I select the parts of my drawing I have to change. I empty the inside of my rocket and I select a thin and black outline.
Warning: when you import and vectorize images on Illustrator, check if your drawings don't have double lines before printing.
To print some text on the Vinyl Cutter it's pretty easy. You just have to select the font and the font size. The next step is to empty the inside of the letters and draw a thin outline.
My template is ready, it's time to print it! To set up the machine, I learn how to: put the sticker paper, adjust the little wheels, select the sticker type (roll, piece or edge), check the paper size and initialize the origin. Before printing, I have a look at my Illustrator file. I can't select all the distinct objects. Before printing, I have to delete a layer and to ungroup everything. I used different version of Illustrator maybe it is the reason why.

Here, download the vinyl cutter file.