Week 03 Computer-Controlled Cutting

Assignments

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.
- 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.
• Identify and explain processes involved in using the vinyl cutter.

Have you answered these questions?

- Linked to the group assignment page.
- Reflected on your individual page what you learned of your labs safety training
- Explained how you created your parametric design.
- Documented how you made your press-fit construction kit.
- Documented how you made something with the vinyl cutter.
- Included your original design files.
- Included hero shots of your results.

Demonstrate and describe parametric 2D modeling processes

We started off this week working on our group assignment which included working on safety training and kerf testing.

Safety training

As I'm working through Fab Academy, one of the first things that has been drilled into us is the FabLab safety rules. The rules keep us safe and the lab running smoothly.

The big takeaway is: be responsible, be prepared, and never assume. We always need to always follow instructions, written and verbal, and if something isn't clear, ask before doing anything. A huge rule is that we should never work alone in the lab. An instructor has to be present at all times.

Respect the space and the equipment. That means no eating or drinking in the lab, no touching equipment until instructed, and only working on approved projects. It also means keeping the work area clean, pushing in chairs, and keeping aisles clear. Good housekeeping is an important part of safety.

Stay focused and aware. It's important not to distract people working on equipment and personally we need watch our own projects at all times and be alert for anything that looks unsafe. Also if we see something wrong, tell the instructor right away.

Know the safety basics. We need to know where the first aid kit, fire extinguisher, fire blanket, fire alarm, and exits are. During a fire drill, we need to close containers and turn off electrical equipment. When handling sharp tools, carry them pointed down and always cut away from my body.

If something goes wrong, report it immediately. Even if an accident or injury seems small, the instructor needs to know. For serious injuries, the protocol is to call out "Code one, Code one" to get help fast.

These rules are important because FabLab work involves real tools, real materials, and real risks. Understanding and following them is what makes it possible to learn and build things safely.

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Parametric design

Definition
2d parametric design: a computer-aided design (CAD) technique where two dimensional drawings are created and modifed using parameters, variables, and geometric constraints instead of static, manual drafting (source: AI Overview-Google)

Since I have a programming background, parametric design is a concept I can relate to. The idea of creating a drawing (the hard part) and then being able to update it with parameters allows me to quickly make changes minimal work. If done correctly, any changes made will be updated automatically...you heard it...if done correctly.

In Fusion 360, I started with a new project, creating a part (I'll talk about that later) and creating a sketch. I picked a plane (usually XY because right now that makes the most sense to me) and started drawing lines, rectangles, and circles all over the place. What took me a while to understand is constraints. It was very frustrating to work through a tutorial and they would talk about the lock on the sketch, how everything was black and constrained. Okay, mine was still blue in areas. Do I care right now? No. Had I reviewed the video in Kevin Kennedy's recommended series? No. Have I now? Yes. Life is a bit easier now because of that video, but you don't know what is important until you start pulling your hair out.

How do I define constraints? I don't. According to Claudi AI, they are rules you apply to your geometry. Okay, great, but it makes designing as a beginner very frustrating. Claude AI, how do constraints help me as a beginner so I can appreciate and not cuss it? "Constraints are really useful because they let you lock in the intent of your design, not just the shape. When you constrain a sketch, you're telling Fusion 360 how the parts of your design relate to each other, so things behave predictably when you make changes." Okay, I can accept that.

Back to the star of the show....Parameters!

How do you create them??
- Modify > Change Parameters
- In the Parameters dialog box, click the + button to add a new one (1)
- Give your parameter a name that makes sense (no spaces, please)
- Set the unit type (I like "mm" personally)
- Enter the value
- Click OK to save the parameter (2)
- Click OK to close the PARAMETERS window if you have finished entering all values (3)

Now when I give a value in a sketch, instead of typing a number, type the parameter name into the dimension field and hit Enter. Guess what? I can also use math expressions that use other parameters, like box_width / 2 or tab_width + kerf. To edit the parameters later, just go back to Modify > Change Parameters, update the value, and every dimension referencing that parameter updates automatically. Voila! It's a sight to behold.

The biggest lesson for me was that parametric design saves time. If I take the time to set up my sketch with the proper constraints and named parameters from the start, making changes later is easy, which I am all for easy. If I rush and leave things unconstrained, stuff breaks when I try to edit it.

My project construction kit for this week

Drum roll please....my kit is a very simple phone holder. Why overdo a design when you can keep it simple and elegant? Dr. Taylor informed me my phone holder is not a kit. What? Okay, can we just call it a kit temporarily until I get my act together? Plus it is all I have. Seriously, I will improve upon it. I really struggled this week and probably panicked a little as well. Time absolutely flew by over the weekend while trying to get this together. My novice (that's putting it nicely) skills with fusion 360 caused me quite the internal struggle.

Simple phone holder

I know this looks simple, but it took far more hours than I'd like to admit.

Update: I have abandoned the phone holder idea. I started looking at other tutorials and there was one that created a sphere out of cardboard. I must be learning something because I was able to recreate this sphere without too much frustration. My only issue was I didn't know how to separate it and turn it into a workable 2d design.

It did give me an idea though. I could create a series of circles and a couple of rectangles, all with slots and maybe Dr. Taylor would consider that a construction kit. We'll see about that one.

At first I asked Claude if he could give me a python script that would do this for me. He obliged with this code.
It gave me the following instructions to add it:
- Click "Utilities"
- Click "Add-Ins"
- Click "Scripts and Add-Ins"
- Click "+"
- Click "Create script or add-in"
- This will open the window below

- Keep the default "Script" selected
- Enter a meaningful name
- Select "Python"
- Click "Create"
It was very anti-climatic. It takes you back to the Scripts and Add-Ins window. Now what?
- Click on the name of the script you just created and click the "pencil" icon at the top of the window.

- The script will open in your default editor and it will consist of sample code. Erase it all and copy the code that you want to use and save it in your editor.
- Go back to Fusion 360 and click on your script name and press the "Play" button.

At that point, if there are not any errors, the magic happens. The circles were created with slots! Sweet! Now all I have to do is add the parametric values and I'm done.

Not so fast...

I had issues with constraining the slots with the circles. I should have written it down, but basically nothing was behaving as it should so I abandoned the script and started working the old fashioned way. I created my parameters. I couldn't figure out how to dynamically create the number of circles that I needed and per Claude that is the purpose of the python script. Fusion 360 can't do that natively. I will research that further. I wanted each circle to reduce in diameter by a certain amount based on the given starting diameter, so Claude created a formula for me based on the order of the circle. For each variable (s0, s1, s2, etc.) I increase the value where zero is located by 1.
sqrt(( sphere_diameter / 2 ) ^ 2 - ( 0 * material_thickness ) ^ 2)

I created 9 circles on a construction line to keep the centers constrained. For the first circle, I gave it the diameter value of s0 * 2. For the next circle, it was s1 * 2, etc. For some reason s1 & s2 always have the same diameter. That's on my "to-do" list to understand why.

After I created each circle I added a slot from the center of the circle to the edge. I trimmed the rounded edge of the slot and then for each point that was left behind I clicked coincident along with the point and the edge of the circle. I constrained the width by the material thickness - kerf. I finally found a system that worked. I could duplicate it over and over without any issues. Major milestone!

Now, when I change the sphere_diameter(I should rename that to circle_diameter) parameter everything adjusts accordingly. I added a couple of rectangles with slots and now I am ready to cut.

I saved my file in Fusion 360 and then exported it as a dxf file. I opened it in Adobe Illustrator and chose the defaults.

It had some artifacts that I needed to clean up. In the screenshot below, the arrow is pointing to my construction line. It is easy to remove it Illustrator, but I will see if there is a way to exclude it from exporting.

To remove the unwanted lines, just click it and delete. If the whole image deletes, undo (Command+z on a Mac), right-click and select "Ungroup" or "Ungroup All" and then try to delete the line again.

Once the image is cleaned up, save it as a svg file and import it into your software to cut. At school, we have an Epilog laser cutter which can print directly from Corel Draw, but the home consumer cutters have their own software you have to use. I have the Xtool S1 cutter and I use the xTool Studio to finish the process.

• Create a new project
• Import the svg file
• Place the material on the bed
• Place the laser over the material and click "auto measure" (1) within the software so the laser can determine the distance to the material
• Click the icon "mark processing area" (2)
  
• Click the geometry of the material (in this case rectangle) and click "Start Marking"
  
• Move the laser head to the top left corner of the material and press the button on the machine
  
  
• Move the laser head to the bottom right corner of the material and press the button again
  
• Click "End Marking" and "Done"
  
  Now the cutter knows the area of the material

• Confirm the image is within that area and if not arrange the parts until they fit or make a separate cut. The highlighted area in the screenshot below represents the material. You can see the laser is going to cut outside of that area unless I rearrange the parts.
  
  Parts within the marked area

• Click "Framing" to confirm the laser is not going to cut off of the material

• I like to always preview the processing path to make sure the cutter is not going to have any odd paths. This particular software shows the path in dotted red lines.
  
• Confirm power setting is around 80% and the speed is between 35-40 and click "Process" to start cutting
  
  
• The cut does not take long (around a minute), but even if it did, never leave the area. There is always a chance of fire.

Construction Kit

Once I cut the shapes out, I confirmed the fit was tight and I could construct several different objects out of them.


These were cut out twice


Fun project. I can't wait to have time to keep working on Fusion 360.

Vinyl Cutting

Yes! Something that did not cause too much pain and agony.

I found my childhood superhero emblem (hint: he flies faster than a speeding bullet) and decided I wanted that as my sticker.

It's a PNG file so I have to find a way to convert it to vector. Adobe Illustrator has that feature.

Adobe Illustrator: Image Trace for Vinyl

• Open Adobe Illustrator and create a new document. Go to File > Place and select the image. Click on the artboard to place it.
• With the image selected, go to Window > Image Trace to open the Image Trace panel.

• The Image Trace panel controls how Illustrator converts the raster image into vector paths. For a vinyl sticker with distinct color regions, use these settings:
  Basic Settings

  1. Preset: Set to Custom so you can fine-tune the parameters
  2. Mode: Set to Color for multi-color artwork (use Black and White for single-color designs)
  3. Palette: Set to Limited to reduce the number of colors to a manageable count for vinyl cutting
  4. Colors: Set this to the number of distinct colors in your design. For the Superman logo, 3 colors works well (red, yellow, and black)

• Export as SVG

Silhouette Studio: Cutting out the Image

• Prepare the vinyl stickers on the mat
• Open the SVG file in Silhouette Studio
• Select the material (1)
• Select the operation (2)
• Start with the blade depth recommended for that material (3) and generate a test image (4)
• Once you confirm your test cut is successful, click Send (5)

Transferring the Image

• Weed each layer. Remove the excess vinyl around your designs on all three layers, leaving only the parts you want on the backing sheet. Take your time with small details.
  Images cut and weeded - still need to remove the surrounding vinyl
• Decide your stacking order. Figure out which layer goes on the bottom (largest/background), middle, and top. You'll build from the top down. In my case I started with the red.
• Apply transfer tape to the top layer. Cut a piece of transfer tape, peel the backing, and press it onto your top layer (the one that will be most visible). Press down well with the squeegee so it grabs the vinyl.
• Peel the top layer off its backing. Slowly peel the transfer tape up — the vinyl design should lift with it. If pieces stay behind, press down and use the squeegee again.
  
• Align and apply the top layer onto the middle layer. This is the hard part. Hold the transfer tape at an angle so you can see both pieces, line the edges, then slowly lower it down. Press firmly.
• Peel up both layers together. The transfer tape should now lift both the top and middle vinyl layers together off the middle layer's backing.
• Align and apply onto the bottom layer. Same process — carefully position and lower into place.
  
  A little help from Angela and Dorian
• All three layers are stacked on transfer tape. Apply this to your final surface. Use the squeegee again to transfer the vinyl, then slowly peel the transfer tape away at a sharp angle.

Final product and it's final resting place

Files

• Circles - Python code: sphere-2d.py
• Sphere Fusion 360 tutorial project: sphere.f3d
• Circle construction - Fusion 360: circle_construction.f3d
• Circle construction - Adobe Illustrator: circle_construction.ai
• Circle construction - SVG: circle_construction.svg
• Fusion 360 parameters: parameters.csv
• Superman - PNG - superman.png
• Superman - Adobe Illustrator - superman.png
• Superman - SVG - superman.png
• Superman - Silhouette Studio - superman.studio3

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