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Computer-Controlled Cutting

Hero shot

Group Assignment:

  • Do your lab's safety training.
  • Characterize your laser cutter's focus, power, speed, rate,
    • kerf, joint clearance, and types.

Individual Assignment:

  • Cut something on the vinyl cutter.
  • Design, laser cut, and document a parametric construction kit,
    • accounting for the laser cutter kerf,
    • which can be assembled in multiple ways,
    • and for extra credit, include elements that aren't flat.

Laser Cutter

Finally, the first week working with the machines in the fab lab. Our laser cutter is an Epilog Laser Mini Helix 24.

FreeCAD

To begin, I opened up FreeCAD as that is my choice for CAD software. I started by creating a spreadsheet and set it up like this:

Spreadsheet

Next, I started to sketch the base of my parametric construction kit. After a while, it looked like this:

First Parametric Kit

After that, I started to make it parametric by double-clicking on the dimension and pressing this button:

Parametric Button

Then I could type, for example:

<<<spreadsheet>>>.b2

Setting up alias

I could also go and type in this box on the top left corner of the spreadsheet tab:

Alias

Type, for example, mt for material thickness so instead of doing:

<<<spreadsheet>>>.b2

I could do:

<<<spreadsheet>>>.mt

After setting that up, I had a box with a slot in it that I could change (almost) anything about. But that was a little too simple, so I saved and decided to add two slots on the side. Here is the first sketch I did.

Making it More Complicated

Second Parametric Kit

The next step was adding the side slots, and this is where I really struggled. I had not learned enough about constraints, and that was really beginning to show as I was having a lot of issues trying to get everything constrained and not moving around. After a while and a little help from Svavar Konráðsson, it finally worked. But for other people, I beg of you to learn how to do constraints before trying to make a parametric design in FreeCAD. Digikey makes good tutorials. Here is one on constraints. Anyways, after the whole constraints trouble, I had a finished parametric kit. The next step was to calculate everything about my laser so everything would connect together nicely. You can find more information about that on the group assignment page here.

Vinyl Cutter

In our lab, we have two vinyl cutters: the Roland BN-20 (Cutter/printer) and Roland GX-24 (Cutter).

Inkscape

My dad owns a bar and asked me to get him an NFC tag so he could give guests access to the Wi-Fi. This has been on my to-do list for a while, so I decided to quickly make a sticker that could go over the NFC tag. The sticker will keep it attached to the bar so it won't be lost. So I opened up Inkscape and made this:

Image of SVG

This file has a dummy QR code just so I'm not putting the Wi-Fi password on the internet, but I changed it to an actual QR code for the Wi-Fi afterwards.