Laura Cristina Massaglia

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ASSIGNMENTS
Computer-Controlled Cutting

The assignments for this week were:

    - Characterize your laser cutter, making test part(s) that vary cutting settings and dimensions.

    - Cut something on the vinyl cutter.

    - Design, make, and document a parametric press-fit construction kit, accounting for the laser cutter kerf, which can be assembled
       in multiple ways
.

Characterize Your Laser Cutter, Making Test Part(s)

    1)  The first step is to draw the 2D model using Inkscape.



    2)  Then you have to save the 2D model in (.dxf) and save it on a pen drive.

    3)  After that open the model in the CutStudio (the machine software).



    4)  Then you need to unite the lines. I did this step by using “Tools(O)> Unite lines”.




    5)  Then you need to use the Corel Draw to realign and change the squares colors. I used the Corel Draw for this step
          because, it was linked to the computer that the machine was hooked up to.



    6)  After that you need insert the parameters that you want to test in the box on the right side. See final image to see
         all parameters that were inserted.



    7)  Once you finished inserting the parameters click on DownLoad.

    8)  After that you need to turn on the laser cutter machine. I recommend running a test first to verify the area you
         are going to use. 

    9)  Finally cut the 2D model. Video here: https://youtu.be/KVU-Q8FnXtg .

Please take a look at the final image below, you can see that I used MDF material at 3 different thicknesses: 3mm, 6mm and 9mm.


Paulo did the math about Kerf to show the machine parameters 
Below there is a demonstration. Also click on the link to his webpage to see more details.

Kerf:

Kerf=With

Kerf is defined as the width of material that is removed by a cutting process.

When cutting parts with the CNC laser machine (which is what I used) or any other kinds of CNC cutting machines you want to produce cut parts with dimensions as close as possible to your programmed shape. Example if you program a 6" by 6" square and the laser removes 0.25" of material as it cuts, then the resulting part  is going to be 5.75" by 5.75". So the actual tool path has to be compensated by half of the tool kerf.  In this case it will be compensated 0.125".


Kerf offset is usually adjusted by who ever is using the machine. Before running a program, the operator must enter the kerf width so that the CNC can calculate the actual tool path required to cut the part to the correct dimensions.


Final comments:


I Learned that the power parameter determines how deep the laser will go through the material. As you can see in our fab lab we have 3 different thickness of MDF material ranging 3mm-9mm. I chose to use the same laser cutter speed for all three thicknesses and start the power of the laser cutter from 18.5-60.  

The Vinyl Cutter Machine

The vinyl cutter machine is Roland Camm-1 CX-24.



Below are the pictures of the front view, rear view and operation panel of the machine:





File Preparation

The vinyl cutter files must contain only vectors; the vectors must be lines only, with no fill; the vinyl cutter drivers can only interpret cut lines. All vectors must be contained within the bounds of the document canvas.You will need to size your page in your drawing program appropriately for the width of vinyl that you are using. Vinyl comes in two widths, 24" and 15".You can  change the width and the height  using Inkscape. The vinyl is on a roll so, the max height could be as long as the length of vinyl on the roll.

Changing the with and hight using ink skape:

    1)  File > Document Properties.



    2)  Modify the width for 23 in and the height for 24 in.



Vinyl Cutter

I decided to make four butterflies to stick on my bedroom wall.I used Inkscape to do it. First I needed to rasterize the JPG image on Inkscape by doing:

Path>Trace Bitmap

After this process, I will have a vector above my image, so I can delete the image and keep just the vector. Then I saved as “.svg” and I  realized that I should save as “.eps” to use the vinyl cutter. I read a tutorial how to do this whole process using Inkscape.

Click the link: https://inkscape.org/en/doc/tutorials/tracing/tutorial-tracing.en.html.

Here are the images of my Inkskape during this process:





(The image on the left side is the one that is rasterize, the other one I deleted)



The next step is to go to theCutStudio software and choose "File>Print". A window will open so you need to choose the Vinyl cutter and click as Printer and then click Print



Now you can load the Vinyl fallow the following steps:

    1)  Select a roll of vinyl and place it on the rollers behind the machine.
   
    2)  On the back right of the machine you will see a lever; place it in the "down" position so you can load the vinyl.
   
    3)  You need to make sure the vinyl side is facing up as you feed it through the rollers into the vinyl cutter.
   
    4)  Under the rubber wheels there is a white sticker indicator.

                o    Ensure that the vinyl is aligned properly under the rubber wheels.

                o    The left wheel must always be under the wide white sticker on the left.

                o    The right rubber wheel must be under any one of the three white stickers on the right, depending on
                       the width of your vinyl.

                o    Make sure your vinyl is straight and about 2-3 inches past the rubber wheels.

     5)  After inserting the vinyl into the machine, pull up the lever at the back of the machine to ensure that the vinyl is securely loaded.



Now you can turn on the Vinyl cutter:

On the left side of the vinyl cutter is the power button, which you need to turn on. Now you need to select press “select roll” on the screen.The vinyl cutter will measure the width of the roll (in mm).Set the origin by pressing the "Origin" button on the control panel. After completing this step and material is placed correctly in the machine, check if it cuts your material properly using the button "Test". If not, adjust the force and the speed, or check if the blade is still good to use or if you need to change it. I chose to use a roll of black vynil material with the force of 100gF and speed of 10 cm/s to cut my image.

After that you can start to print:

To print the file, go to File > Print > select the "vinyl cuter" driver from the print menu.Hit the "print" button to send the file to the vinyl cutter.

You can watch a video here: https://www.youtube.com/watch?v=yRo0vUNnpQ8

After the vinyl cutter is done you need to cut your file, use scissors to cut off the section with your cut design, you also need to weed the vinyl, which is process of removing the unwanted areas from the final cut design.

The tools I used were:
•    Transfer Tape
•    Scissors
•    X-Acto knife
•    Tweezers

Then after cutting, trim area you want to keep with scissors. After that remove the unwanted parts of vinyl with an X-Axcto knife and or tweezers. See the images below:




Once those steps are finished, you are ready to transfer your vynal image to the desired surface. Carefully apply transfer tape to the surface of the weeded vinyl. Rub the transfer tape onto the vinyl to form a strong bond between the tape and the top surface of the vinyl design. Then after rubbing, carefully pull the transfer tape (with the vinyl adhering to it) away from the vinyl paper backing. After you have removed the vinyl from the paper backing and it is attached to the transfer tape, apply it to the desired surface. Rub the surface of the transfer tape to ensure that the vinyl will adhere to the new surface. Then carefully pull the transfer tape away from the vinyl, leaving the vinyl attached to the desired surface.

Here below you can see the vinyl butterfly and the butterfly on my closet:



Paramitizing Design and Laser Cutter

Parmaitizing Design:

What does it mean to parametrize (parametric measures) a model?

Use parameters in Design Studies and link them to variables that can be changed with each iteration of an evaluation or optimization design scenario. You can parameterize model dimensions, global variables, and features from Simulation and Motion studies.Link parameters to input fields to let the parameters drive the numeric value of the associated feature. For example, if you define Force1 as a force parameter, you can link it to a force input field instead of entering a numeric force value. Changing the value of the parameter Force1, automatically changes the force input linked to it.

I decided to designed my Extractor’s support legs using the SolidWorks software. I came up with this idea when I first designed my Extractor and then I realized that I should make a support for it because the solution entrance is on the bottom of the Extractor. The new leg supporters would not only make my extractor more stable but would also add more height from the bottom of the Extractor to any surface allowing more space bellow the solution entrance.

Below is an image from Solid Works of my support design.
Please note that for this specific assignment I only cut the legs and the support table. The conical vase was printed at a later date.


The legs:

Below are two pictures of one leg. The first picture is sketched with a parametric measure and the second is the solid 3D design. When your parametric measure is complete click File> Save as> Choose the “.dxf”.


(Sketch with Parametric Measures)


(Solid 3D Design)

You can watch a video how to parametrize here: https:www.youtube.com/watch?v=ltRL0qXgo2A

Here below is how I got my leg parametrized. It’s not so hard to do and you can fallow these steps on how to design an image using a parametric measure including  a picture of my measurements:

    1)  Insert your sketch

    2)  Click one of the lines of your sketch and then you click smart dimension tool at the top left of the window.

    3)  A small window will appear and Insert the line dimension you prefer in (mm)

    4)  Create a global variable by clicking the tool next to the red x button

    5)  Type an = then type in your name for the variable then accept the variable by clicking on the  symbol

    6)  Click on another sketch line and repeat steps except for this time insert an equation as you can see in the image bellow and
          click accept.

    7)   Continue these steps where you see fit to parametrize the dimensions of your sketch.



The base:

I used the same concept for the base as I used for the legs. First, I got the diameter of 31 (the smaller circle, in the center) and I parametrized all the other measurements starting from this point.  



To do this step I used a function (=“D1@Esboço3”*4.8387) which you can see in the image below:








I also parametrized the extrusion which is shown in the image below:



Laser Cutter:

What are Laser cutters?

The laser cutter/s is one of the most useful tools in a modern fabrication shop or lab. Laser cutters work by directing a very powerful laser beam, at a precise focal length, onto a material which they either cut or etch, depending on how the laser cutter has been set up. Laser cutters cut materials similarly to other computer controlled tools, only they do it using a beam of light as opposed to a blade. Once the  laser cutters are set  up to etch something on the surface of a material, they operate like a printer, basically using their laser beam to etch an image onto something.

I first read a tutorial about the laser cutter before using it:http://www.instructables.com/id/How-to-Use-a-Laser-Cutter/

Below you can see the mane steps on how to use the laser cutter:

   1)   You first  need to have a software such as Inkscape, CorelDraw, Illustrator to convert you image to a vector. I used Inkscape.

    2)   Then you need to choose which material between Cast Acrylic, Extruded Acrylic; ABS; Polycarbonate; Anodized Aluminum;
            Glass; Wood. I used 9 mm MDF material to cut the legs and base.

    3)   After that you need to place your material inside the machine the dimensions. The machine used is model: G-WEIKE laser cutter
          model LC1390. The machine dimentions are: 130cmx90cm


    4)  Once everything is placed, you may need to adjust the bed. There is a focus button on the front control panel of the Laser Cutter.
         If you push that, and then the down arrow, you should see the bed lower. Keep lowering the bed until you have enough space that
         the laser will not come into contact with your materials.

    5)  Now that everything is placed, you need to do a test run. For this step, leave the lid open, otherwise it will not run the test and may
         start to actually cut. Before the actual cut, you may want to ensure that your print area is contained within the space you're hoping for.
        
         There is an easy ways to do this: 
         
         If you tape over your print area, or tape a sheet of paper over the area you intend to print (make sure you cover more than just
         the intended print area, in case your measurements are off, this is what makes a test cut useful), you can etch into the paper
         or tape,and make sure the laser is only going to cut the areas you plan.

    6)  After you run the test you close the lid. Go back onto the computer in the File -> Print ---> Preferences menu, select Raster
         or Vector depending on what you plan to cut. Once that's selected you can, choose the Power and Speed settings that would
         be most suitable for your piece. If you're cutting in Vector, don't forget the Hertz setting. I used speed of 10 and the power of 60
         as you can see in the picture below. I got the speed and power using the MDF laser cutter test at the beginning of the page.



    7)  Here below you can see the picture of my design in the Lasercut software. You need to configure the speed and the power. Once   
         everything is selected, and properly placed, click OK to start printing from the computer.



    8)   If everything looks okay, turn on the exhaust fan. If you're doing a Vector cut, turn on the air compressor and click GO on the laser   
          cutter control panel.

    9)  After that you will have your cut ready.



     10)  Then I used a hand sander  for a betterr finish and a better appearance. My 4 pieces of my extractor support was ready.


(Before Sanding)


(Finished Legs)



(The base after laser cut)

In the pictures below, you can see the base with the legs.



Project Files:
   
   
  Buttterfly
     Legs
    •  Base
     MDF3
      MDF6
      MDF9      

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