Computer-Controlled Machining
Group Assignment:
Do your lab's safety training
Test runout, alignment, fixturing, speeds, feeds, materials, and toolpaths for your machine
Individual Assignment:
Make (design+mill+assemble) something big (~meter-scale)
Extra credit: don't use fasteners or glue
Extra credit: include curved surfaces
Have you answered these questions?
Linked to the group assignment page.✅
Documented how you designed your object (something big)✅
Documented how you made your CAM-toolpath ✅
Documented how you made something BIG (setting up the machine, using fixings, testing joints, adjusting feeds and speeds, depth of cut etc.)✅
Described problems and how you fixed them ✅
Included your design files and 'hero shot' of your final product ✅
Group assignment
Do your lab's safety training
Test runout, alignment, fixturing, speeds, feeds, materials,and toolpaths for your machine
I currently work at Fab Lab iFurniture as a Fab Manager, so whenever we have visitors or organize training sessions, I am responsible for leading this workshop on risk prevention and workplace safety. For this reason, I have organized a group invitation to my colleagues from Fab Academy to participate in this workshop.
Here is the link to learn more about the group project.
I also received an induction from Cristian, who is my instructor in this process, where he explained the use of the machine so I could complete my assignment. I was a bit scared because I was going to operate it alone, I had some difficulties, but I was able to finish my assignment.
Reflections
During this assignment, I learned the importance of safety measures when working with CNC machines. Understanding and applying the safety signs and proper procedures for operating the machine is crucial not only to prevent accidents but also to ensure an efficient and controlled work environment. Correct use of personal protective equipment (PPE) and attention to warning signs are essential for the safe operation of the machine.
Carrying out activities in the Fab was a very rewarding experience. Learning to use the CNC Router was quite a challenge, and configuring the XYZ axes was a crucial step in the process. The training provided by my instructor Cristian was very valuable to me. For this reason, I have documented the process of setting up the XYZ axes and the machine in our Fab Lab, as I know this information will be useful to others when they use this machine in the future.
Moreover, by working with the CNC Router and conducting cutting tests, I experienced firsthand how the cutting parameters affect the precision of the results. The hands-on experience allowed me to refine the choice of joins that were most suitable for the pieces I was manufacturing. In this case, I used the slot join, which made joining pieces accurately and securely easier, ensuring stability and functionality. However, I also identified areas for improvement, such as using the chamfer, which would have optimized the joints and enhanced the final piece's quality.
This process not only allowed me to better understand the technical use of CNC machines but also made me reflect on the importance of following safety guidelines and continuously adjusting parameters to improve results. Correctly configuring the machine and choosing the right joining techniques, like joins, are key factors in achieving high-quality pieces and ensuring a safe manufacturing process.
Individual assignment
Make (design+mill+assemble) something big (~meter-scale)
Extra credit: don't use fasteners or glue
Extra credit: include curved surfaces
For this assignment, I will use three types of joins. Joins are joining techniques used to connect pieces precisely and functionally, depending on the project's requirements. The choice of join type is crucial for ensuring the stability, durability, and ease of assembly of the parts. In this case, three types of joins will be used, each designed to adapt the assembly to different design and functionality needs. Each type has its specific advantages, whether it is for achieving a stronger, more flexible, or more adjustable connection.
And, of course, I have considered the dogbones according to the size of the Router's bit, which is 3.175 mm. Dogbones are a type of cut used at the corners of parts to allow the bits to round off the intersection areas, preventing dead corners that can't be properly processed with the tool. By considering the size of the bit, I ensure that the cuts are precise and that the pieces fit correctly during assembly.
1. Furniture Sketch:
Before I start designing a piece of furniture, I came up with the idea of creating an entry console for the house, with the goal of providing a storage space. Since I'm about to move, I've been thinking of making something that fits the space where I will live in the future. My intention is to create a discreet design that gives a clean and organized appearance. Additionally, I want to use recycled materials from the Fab Lab Ifurniture. The dimensions of the piece may vary in length; initially, the proposal was 1.20 m, but depending on the materials available at the Fab Lab, the measurements can be adjusted. The approximate dimensions would be 40 cm in height, 40 cm in depth, and 1.20 m in length, although the length could be shorter.
2. 3D Modeling:
Designing in Rhino, I used two types of joints. The material adjustment I made was increasing 0.5 mm to ensure the pieces fit tightly without the need for rubber or screws. The goal was to make the joint as precise as possible so that the furniture fits perfectly.
Additionally, I created a rail on the top and bottom to place acrylic and add color to the furniture, as the idea I have for this design is to paint it.
3. 2D Drawings:
I transferred the design into 2D plans to fabricate it precisely.
4. Import 2D Plans into ArtCAM:
I set up the configuration in the tool panel, selected a finishing depth of 17, chose a 3.175 mm cutter in Profiling Tools, enabled ramping moves, and selected 15 mm material. Since I had both internal and external pieces, I started making the necessary configurations, but I also needed a material roughing, which was done with a line.
I saved the G-code and transferred it to the USB of the CNC router to proceed with the fabrication.
5. Material Selection:
They still see me smiling, selecting a material that was available at the Fab Lab iFurniture.
6. Fixing the Material on the CNC Router:
I fixed the material to the sacrificial bed.
7. Cutting the Pieces:
I cut the material, everything still looks good.
There are a total of 3 structural pieces and 2 rest pieces.
8. Sanding and Assembly:
I arrange the materials to sand the wood.
I start assembling the furniture, everything was going well.
Until I realized that the board on top didn't have the holes, and I panicked. I went back to cut it on the machine and lost the XYZ configuration. I tried cutting it with the laser, with a jigsaw, and in the picture, we can see the horrors. 😞
I went back to configure the board in ArtCam since I couldn’t achieve anything with the jigsaw or the laser. I was afraid to use the router again because I had lost the configuration and needed to redo it. And there was no one in the FAB to give me support.
I calmed down, and after wasting time trying to cut with the laser or the jigsaw, I decided to relax and review the recordings I made for my instructor, Cristian, which I documented in the group assignment. The configuration process was slow, but in the end, I was able to set the XYZ axes, and finally, I managed to cut the piece I was missing.
In the end, I was able to finish the furniture. After the desperation, calm came. 😊
After all the stress I went through, the pieces fit perfectly with the pressure. I designed the Dogbone using a 3.175 mm end mill.
This is another detail I found, although it's not as noticeable.
In the end, after hours of work, I tested my furniture. I sat down, stood up, and almost did a handstand, but there's no body left for that, haha. And that's it! The furniture is now ready for any finishing.
9. Wood Treatment (Protection against Fungi, Bugs, etc.):
I sand again to level the joints with the board, ensuring the surface is completely smooth to the touch.
Next, I choose a preservative, in this case, from the Duramad brand, which protects against moths, fungi, and wood rot.
I apply the product carefully, as it is toxic, so protective gear must be used. I carefully apply the preservative to the phenolic pine. This process is done every 4 years to maintain the wood. The climate in Lima is humid, which causes materials to deteriorate and become infested with moths more quickly, so it is important to follow these tips.
10. The Art of Color
Now I’m creating a base with the following list of materials:
Since my furniture dimensions are 1.10 x 0.40 x 0.40, I don’t need much paint, so Professor Gustavo (who is in charge of the carpentry workshop at Melitón Carbajal School, and with whom we share space at the Fab Lab Ifurnitures) gave me some advice that I’m now going to follow. For this, I bought the following:
1/4 gallon of blue paint
1 kg of American talc (it’s sold in bags, so I had no choice, as I was only going to use a small amount).
To make the base, I followed this proportion: in a can, I mix half of the paint, about 9 tablespoons of talc, and a bit of thinner to dissolve it. I stir well to ensure there are no lumps and start applying it to the material with a spatula that allows me to do so evenly.
This is the third day, and I’ve already applied the base. I’m letting it dry before applying the final finish.
Now, on the fourth day of the project, it's time to sand and paint. So, first, I find a piece of wood and, using a 120-grit water sandpaper, I start sanding the imperfections of the base.
After finishing the manual sanding, I started with the painting. I used Gloss Blue paint, poured a bit of paint, and mixed it with some thinner. At first, I was unsure because the paint looked very watery, but when I began painting, I realized that the paint had a good consistency and covered quite well.
And this was the final result. I loved it; also, since I really like the color blue, I was very happy with how it turned out.
Reflections