3. Computer-Controlled Cutting

Group Task

Background Information

• The CO2 laser cutter is the machine used in the lab.
• Materials used for cutting are wood, acrylic and plastic.
• Some types of plastic are prohibited to laser cut like HDPE/milk bottle plastic catches fire and melts and PVC (Poly VinylChloride) /vinyl/pleather/artificial leather Emits pure chlorine gas which is poisonous and was used once in world war 1.
• Three safety measures when operating a laser machine is closing the door of the machine and workshop, making distance to not smell any gas and to keep the AC in the machine on after operating it for a while to get rid of remaining gases.
• When Materials are on burning (Fire), Fire Blankets are used to close on the gases of materials in the CO2 that are burning which in long-term will end the burning of the material without spreading it.
• we export as .Stl because they are solid files, formattable, describe the surface geometry of a 3D and are commonly used to print with standard 3D printers (Universal file format readable by all 3D printers). Source
• in case of fire, it is required to use the fire blanket to turn off the flames, it works by isolating the gases inside the machine and not allow them to spread through air or materials which causes them to eventually stop the fire.
  

Focus

We know from physics that lasers have a focus point where the laser have the highest focus resulting in thinnest cut and highest power, cutting at the focus point helps us attain the highest efficiency possible for laser cutting which helps us create the pieces we need.

Ramp Test

The most Efficient test to determine the focus point of the laser at this era for different laser cutting machines, the test is as follows, you add a piece into the corner of the piece you want to cut and then align it to create an angle where the laser travels farther as it cuts the pieces.



We found that the optimal value for laser cutting is 0.7 +- 0.1 mm using a ruler which is close to the real optimal value which is 0.8 mm, we compare it using a lego piece

Parameters (Other Groups)

Other Groups did tests that found the optimal values for wood which are: -
1. speed: 90 mm/s - Sayed Ali Group
2. Power: 80 Watts - Sayed Ali Group
3. spacing: 1.65mm - Zainab Group
4. focus: 0.8mm - My Group (This Site)

Individual Task

1. CO2 Laser Cutter [Pressfit]

CO2 Laser Cutter is a machine used to cut acrylic and wood, it’s laser is strong and sharp that it can cut these components and even cause burns when using cutting.

We used the CO2 Laser Cutter to create a pressfit design, and cut it to create 12 pieces with the wastes from cutting, a design have been created as follows:-

Issues: Having a slight turn or inaccurate data when laser cutting can cause you to face problems when connecting pressfit pieces together, requiring more force for connecting them and causing the pieces to break when not proceeding slowly in work

Steps to create Pressfit design

Pressfit file

Download as .DXF - Download as .F3D

What makes the design Parametric

The distance in between the pieces to attach in the system is Spacing found in the Parameters of value 1.65 mm.

Steps:-

1. Change Parameters (Solid => Modify)
2. Add Parameter & Name (Panel)
3. Edit Sketch (Left Bar > Right Click)
4. Sketch Dimension (Sketch)
5. Add Sketch Name
6. Enter

2. Vinyl Cutter [Sticker]

we downloaded a silhouette of the design we wanted then sent it into the fablab share gmail to get the file into the vinyl cutter machine, then we used it to cut sticker then stick them into the place we wanted, I used the sticker I cut on my phone cover to make it more noticeable and appealing.

Background Information

Vinyl Cutter Type is Silhouette Cameo with a 3 mm thickness clearance to cut, it cuts the materials with a blade, the steps to cut are as follows:
1. take a Sticker Mat
2. put it on Worklion Cutting Mat
3. add the Silhouette Image into Silhouette Studio Program
4. Adjust Size
5. Send File into the Vinyl Cutter
6. Start Cutting
7. Remove Sticker from Cutting Mat (I removed it by hand and placed the excess piece on my phone cover)

Owl Silhouette Download - Use (Right Click) On Image then (Save As) Option to Download

Issues: The Result is nice and just as wanted, the only issue is that the place used for it can not allow it to stay forever unharmed, causing it to wither with time.

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Last update: September 10, 2023