For this week assignment we must use two different CNC machines to translate some digital designs in matter. The last week assignment I also used the laser cutter to create my design, but this time I will do a parametric make up box for my girlfriend and some stickers in the vinyl plotter. For the vinyl I will work some sandblasting also.
I will start with the vinyl cutter design. I'm a big fan of science fiction, comic books, geek culture, etc. I will cut some stickers that I want but can't find anywhere. This designs I will put them in my laptop. For this designing stage, I will use Illustrator software. I named it vinyl cut design
For this design I will use the automatic vectorize tool of illustrator. I will take some black and white picture from internet of some manga or comic that I like and I will process it with Illustrator in order to cut it in our plotter.
I searched in google for the rorschach symbol of the character rorschach from the Alan Moore's and Dave Gibbon's graphic novel, Watchmen. I did right click over the picture to display the menu, I chose copy.
Now that we have our picture in Illustrator we can use the automatic tool to vectorize.
Now we go again to the top menu, click over the object menu and look for the option named live trace. and we click it to display another mini menu. We clicked in create.
Then we export our vectors in .dxf. We go to file menu, then export, then we choose the extension.
Then we open the Silhouette studio software, that's the driver software that we use to convert the vectors into Gcode for our plotter. We have a Roland plotter and a Curio Silhouette which is a desktop solution for the vinyl cutting.
This software is really easy to use but it doesn't have good tools to edit or draw shapes, and when you open the file, the size will be modify. There is no tool to modify the sizes with numbers so it's unprecise. I modified the size to do it smaller manually, clicking and dragging to cover all the figure with my selection, then going to a corner clicking and dragging to make it smaller. I kept the rectangle in which is contained to avoid wasting too much material.
The Silhouette Studio has already some parameters for different materials saved. First we must pick from the different options of cut zone, we pick cut, and the figure will be highlighted in red. If we pick cut perimeter, it will highlight the rectangle that contain it. Then we can choose the tool between tool 1 and tool 2; our cutter is positioned in the tool 1. If we pick tool 2, it will be highlighted in blue.
For the cutting parameters with choose Silhouette vinyl, the problem is that the vinyl that it got registered is thinner than the one we have here, so instead of keeping the cutter with a deep cut level 1, we modify it to level 2. Speed I choose 5 cm/s that it have from fabric. The thickness of the material it has it like 10, the problem of this software is that it doesn't have units for the thickness, it only says that is 10, so we cannot adjust that one, instead we change the cutter level to 2.
Now we send it to cut. The machine took, aprox, 1 minute and a halfcutting. It didn't take out any line, the cut was perfect. The design was easy to depilate.
I used then trasnfer paper to transfer the vinyl to my laptop.
After that, I decided to do some experiments using vinyl and sandblast to obtain a different finish depending on the material. I follow the same steps described in this page to vectorize two new images and cut them in vinyl. One picture is the greek Phi letter which is the symbol for psychology, this will be added into a Cup to do the sandblast and gift it to my sister, the other picture is a Ganesh deity picture to put it in a crystal vase and gift it to my girlfriend.
First we put the vinyl into the surfaces, we use transfer to do that, we must look for wrinkles and try to eliminate them. We cover with masking tape the surrounding areas to avoid being hit with the sand.
The sandblasting is a process that is made manually so while you are doing it you must stop and watch how is coming along. What I was looking for is a pale red in the case of the cup and a silver white in the case of the glass. I can keep shooting till the material loses all paint but I prefer to keep it there. After that you remove the tape and the vinyl and is done.
For the parametric design that will be laser cut, I designed a make up box as a gift for my girlfriend. For this assignment I decided to use AutoCAD software because it counts with some parametric tools that are easier to use.
First I use the parametric menu on the top of the program, depicted in the image above. I clicked over the parameter manager. This will open the window, thiss tool is the main tool for the parametric design in AutoCAD, in this tool I will save the parameters and its values, the important thing to notice from this tool is that the values of the parameter can be saved as formulas, this will let us reference every value to one value. For this design I based it in two parameters, the base width and the material thickness, but of these parameters are named base and mat1.
I discover that the easiest way to do this is side by side. The reference for this design is the base piece, this piece will be the bottom of the box, so it will tie together with prest fit the other fourth sides. First I registered the parameters for the base and the parameters for the press fit mark. Every parameter should be referenced to my base. For example, in the bottom piece, the base width (my main parameter( will be 300mm the and the height will be 200. In order to make it parametric I don't insert the value as 200 mm but as a formula, in this case is base-100. The press fit marks will be formulas as well, in the width parameter, the parameter for the press fit mark will be called pestbase, and its value is base/9. So the first step is introducing all of the parameters.
The method that I discover to do this is, trace 3 press fit marks, select all then in the parametric menu choose autoconstraint. With this, when you change the parameters the lines won't lose the position. Then you will pick everyline with the parametric menu tool linear, then it will appear a quotaiton that you can write on, you will write the name of your parameter and it will adjust, for this step will use the parameters for the size of the press fit marks and the parameter mat1 (material thickness) for the height of the pressfit marks. After this step is done you will select your three pressfit marks and copy them and paste them the times you need for that side. Continuing withe base width example, the pressfit marks were divided by 9, so we need 9 pressfit marks.
So it will look like the image above. You do this steps for every side of the box. until the box is complete. With these steps every side will be base in the base width and the material thickness.
Now we must check the kerf and settings of the laser cutter we are going to use for this protoype. The machine that we use is a CamFive CFL-CMA1080K
The file that we use to test the kerf and the mark speed can be download from here, It was made by the thingiverse user Elplatt and published in may 2013. File
The file works with two main parts, a vertical bar with engraved number in inches and a 4 gap square which will slide in the bar. Each gap is for a different material thicknes. the bar has a unnoticeable leaness that varies for the kerf and the value engraved is divided by 4 because the kerf is 4 times effective.
For kaling it work you use the silder and you stop when you can't slide anymore, you look at the engraved value and that's the kerf. In our case we converted it into milimeters.
We adjust the parameters for the laser cutter which are this ones:
Max power: 65%
Min Power: 55%
Work Speed: 25 mm/s
After the cut was done we need to check if the Kerf was correct.
We do the conversion to check the Kerf in mm
The kerf for our machine is .05 mm
After that I send it to the laser cutter, the model we have is a Cam 5. The parameters I usually use to cut MDF of 3mm is Max power: 75%, Min power 70% and Work speed 23 mm/s. These parameters are depicted in the picture below.
These are some pictures of the process.
After it was cut, it came the assembly time, in this assembly I found some dificulties withe back part of the box. It was 6mm short in width and the press fit marks to put the division were 3mm to the left of the press fit marks in the division. This mastakes made the boxx impossible to be assemble in a correct manner. This changes though, are easy to make because it's only failing from one of the sides.
After the cutting process the ensambling was really easy. The parts assemble without a problem, in the case of the box, the press fit was tight. In case of the drawer, glue was needed and I required to modify the file twice because it was too fitted inside the box.
After assembling the two drawers, the box was complete.