For this group assignment, I will be using the available CNC Router, as our milling machine is out of service. With the help of my instructor Cristian, we conducted several tests and obtained different results.
To start documenting this assignment, I met with my instructor Cristian, who provided some guidance. He shared recommendations based on the work he and his group did last year. The only difference is that, in my case, we don't have a milling machine to make our PCB, but we do have a CNC Router that will also help us with this task.
One of the things we were missing in the Fab Lab iFurniture were the end mills. We ended up purchasing a 30° angled end mill and a 0.5mm cutter tip. I found this end mill at the following link. Mecatrónica Saisac
To cut the bakelite material, we purchased another end mill that would assist with the cutting, a cutter with a 2mm diameter. I also found this end mill at the same previous link. Mecatrónica Saisac
These are the electronic components that will be used in the individual assignment, but it is important to know them for this group assignment. This will help ensure that, when making the cut, we are working at the correct scale.
The machine we will use, which is available and easily accessible, is the CNC Router, the same one we used in the previous assignment. Although it is a larger-scale milling machine, it can also help us carry out this assignment of milling bakelite. This is the first time we are using it in the Fab Lab Ifurniture, so the process will involve trial and learning.
Here are the machine specifications.
| Specification | Details | |
|---|---|---|
| Cutting Area: | 1220 mm x 2440 mm x 150 mm | |
| XY Positioning Speed: | Variable, max. 1800”/min | |
| Z Positioning Speed: | Variable, max. 900”/min | |
| Input Voltage: | Single-phase 220V |
When purchasing the end mills, one of the key considerations was the shank size, which is 3.175 mm, as this is the correct size used by the machine. We decided to replace the previous end mill with a 30° V-shaped end mill with a 3.175 mm shank and a cutting diameter of 0.5 mm.
I downloaded the Traces+Exterior file in PNG format from the Academy website. Since the CNC Router we use in the Fab Lab operates with the ArtCAM software and the model configuration needs to be in DXF format, I proceeded to open the PNG file in Inkscape to convert it to the appropriate format.
To vectorize this PNG file, I go to the "Path" menu and then click on "Trace Bitmap" to convert the image into a vector file.
I select the PNG image and press Enter to apply the tracing and convert it into a vector file.
And done! The image is now in vector format!
To do this, I open the file in Rhino and adjust the lines to ensure that the ArtCam software recognizes them correctly.
I tried to do this assignment with the laser, but the laser didn't make a dent. So, I took a chance and did it with the Router.
Once the design for the PCB was configured in ARTCAM, I proceeded to cut it with a thin 0.1 mm bit with a 15° angle. We got this bit later to be able to cut my individual project board. The challenge with this board was being able to cut it, but the difference was that the tracks in this design were thinner and the scale was about 37 mm. So, as I was milling the lines, I ended up milling everything. 😞
So this little board ended up, sad and empty.
However, since I wanted it to turn out well, in the workshop, they did the cutting service for me so I could see the differences (don't forget to include the specifications).
The first thing I do is create an account to access the service on the website.
I enter my details, create a password, and that's it, I click on 'Sign Up'.
In the box, I need to enter a code that was sent to my email to be logged into the account. Once I enter the code, I click 'Submit'.
The website gives me a brief explanation of how it works.
Once this is done, I make a selection of how I want my PCB to be. In my case, I chose 'Standard PCB', which links me to another page.
To get a quote for my design, I need to upload the document in Gerber format, which I do from the KiCad software by following the plotting process, and there I find the option to save as Gerber. Once this is done, I upload the design on the PCBWay website.
Once that's done, I leave the specifications as default. Now I can see my design previewed on the website.
Now, in the green box area, you can see the price of the PCB and the shipping cost. And you can make the purchase online, just like in any online store.