3. Computer Controlled Cutting

Group assignment

This week's group assignment consisted of characterization on focus, power, speed, rate, kerf, joint clearance and laser cutter types. The group assignment is at the following link.

What did I learn from the group assignment?

From this assignment I learned to not only use the laser cutting machines that the university has. I learned some things that allow the machine to deliver better results. For example, the use of the kerf for the individual activity was very important because it allowed me to pressure assemble the parts to fit well. As for speed and power, I learned how to adjust these parameters so that the laser cutter would do a good job. By this I mean that it would cut all the parts without burning the material.

Laser Machine

The laser machine I used to cut my construction kit is the CFL-CMA1080K machine.

This machine has the following features:

Work area:1.00 x 0.80 meters
Work table:Honeycomb or rod
Accesory:Double Tube
Cutting speed:0–36,000 (min/mm)
Engraving speed:0-64000 (min/mm)
Power:100 Watts
Cutting thickness:0–25 mm
Resolution:Up to 4000 DPI (typically between 600 DPI and 2000 DPI)
Motion accuracy:0.01 mm

The steps I followed to use the machine can be found in the following link.

Type of material for laser machine:

The material I used to assemble the kit is MDF.

MDF (Medium Density Fiberboard) is a versatile and cost-effective type of pressed wood fiberboard used in furniture and woodworking projects due to its easy handling and uniform finish.

Individual assignment: construction kit

This assignment consisted of making a construction kit using CAD software. The software I used was Fusion 360. I used this software for two reasons: the first is because in week two's assignment I learned how to use that software and the second is that SolidWorks was taking a long time to load on my computer.

Parametric design

Parametric design in allows for creating 3D models with adjustable parameters, facilitating iteration and design optimization.

My construction kit is made with parametric design, which allows me to make modifications to the figures I drew.

To calculate the "kerf" or the amount of material burned by a laser cutter, several cuts can be made in a material and the space created by these cuts can be measured. By dividing the total width of the gap by the number of cuts, the kerf width is obtained. For example, in the group activity, by making 10 cuts in 3 mm MDF with a speed of 40 mm/s and 50% power, and measuring a total space of .123 mm, the resulting kerf is 0.123 mm. This value was used to adjust the dimensions in the fabrication of my construction kit, ensuring accurate assembly.

Development of figures in Fusion 360:

All the tools I used in Fusion 360 are the ones I learned in week two. You can check out week two here.

Figure 1. Main piece: A rectangle with tabs and some holes to insert other pieces.

Figure 1 parameters:

Figure 2. Main piece wall: A rectangle with holes to insert other pieces.

Figure 2 parameters:

Figure 3. Main piece ceiling: A rectangle with tabs and a design in the center.

Figure 3 parameters:

Figure 4. Wheel.

Figure 4 parameters:

Figure 5. Other wall type.

Figure 5 parameters:

Figure 6. Elbow.

Figure 6 parameters:

Figure 7. Triangle.

Figure 7 parameters:

How to export the files in Fusion 360?

Step 1. Select the export option in the upper left corner.

Step 2. We name the file and choose the .dxf format.

The .dxf format is preferred for laser cutting because of its wide compatibility with CAD/CAM software and its ability to preserve accuracy in design details, facilitating the transfer and production of complex parts.

Step 3. Next we save the file to some location on our computer.

Step 4. Select the export option and wait.

Step 5. For the last step we select all the files in .dxf format and transfer them to a USB flash drive.

Development of construction kit on laser machine. :

To use the laser machine I used the machine software. The steps to turn on and use the machine are in the group activity that you can consult in the following link.

Before cutting my figures on the laser machine, I made tests, to adjust the speed and power. Something I considered to make the adjustments is the thickness of the MDF, in my case the MDF I used has a thickness of 3 mm.

I started with the following parameters:

Maximum power: 60
Minimum power: 50
Speed: 25

I had to make several adjustments because in the first tests, the machine did not cut the figure.

As you can see in the picture, my first attempts went wrong. The machine did not cut my pieces well. What I did is to increase the three parameters until I got a good cutting result. The mdf I used was 3 mm. So I decided to add 15 to the power values and decreased the speed to 20. With these parameters I got better results and my pieces came out well.

In the end these were the parameters I used:

Maximum power: 75
Minimum power: 65
Speed: 20

The result is as follows:

And these are all the pieces I cut:

The figures I assembled with my construction kit are as follows:

Figure 1:

This figure is a car, in the back I put some thrusters.

Figure 2:

This figure is a cell phone holder, I changed the wheels for the triangles and put some arms with elbows to hug the cell phone.

Figure 3:

These figures are airplanes, made with triangles, elbows and wheels.

Figure 4:

This figure is a combat ship, the wheels represent the propellers of the ships and I put elbows with triangles as the weapons.

Figure 5:

Finally, I made this figure. It is a stand for my setup, I can put keys, key rings, figures, small things, etc.

Individual assignment: vinyl cutter

The machine I used to make the vinyl cut is the Silhouette model. You can find it on Amazon in the following link.

To use this machine you must download the software to your computer. You can consult the software in the following link.

The Silhouette Portrait 3 is a cutting plotter that is small in size and price, but big on features and functions. The Silhouette Portrai cutting plotter is the best value electronic cutting machine on the market. It allows the use of the new Silhouette AutoBlade 2 auto-adjusting knife (compatible with Cameo 4), as well as blades from previous models using an adapter set sold separately.

Machine features: