For our seventh assignment, the CNC machining, we had to mill a 3 dimensional object that had the following characteristics:
- Your object may start as a file or an image or a .svg;
- You may cut your object from any material: foam, wood, wax.
“CNC mills use computer controls to cut different materials. They are able to translate programs consisting of specific commands to move the spindle to various locations and depths. Many use G-code, which is a standardized programming language that many CNC machines understand.” Wikipedia – Numerical Control
Therefore, the project would be divided in three parts:
- Finding or designing an object to make using the CNC machine;
- Producing your object with CNC machining;
- Post-processing.
During this posting, we are going to describe the processes we had in order to create our final object!
- Finding an object to use in the CNC machine:
In order to find a drawing in the .svg format to mill using the CNC machine, we used the website called The Noun Project and we found the internationally famous Mario’s mushroom, the make him get stronger (red mushroom) or gives him an extra life (green mushroom).
After choosing our drawing, we proceed to a website called Easel Inventables where we were able to generate a G-code and and prepare all the settings, such as: cut depth, bit size, deep per pass; for the CNC machine.
2. Producing the object:
(i) First trial:
As our first trial, we decided to use a machinable wax to print the mushroom. After generating the G-code on the Easel website using the CNC machine is pretty easy, once we dont have to define any settings.
The only problem we had to mill this mushroom was the size of the mill we used in the website. The one we used was 1/32 in, but in the machine shop we only had the size 1/16 in, so the image was too small for it. Therefore, it didn’t mill one little part in the base of the mushroom.
(ii) Second trial:
As our second trial, we decided to decided to use wood and try to conclude the project. After cutting the wood, having some problems fixing it on the CNC bed and a lot of sanding; we were able to mill it.
(iii) Third trial:
After milling the other mushroom in wood, we decided to mill another one so that we could have a red one and a green one.
3. Post-processing:
(i) Red mushroom:
For the red mushroom we decided to spray the whole surface with red paint and then use the orbital sander to remove the most superficial layer and have the red on the deeper ones. After sanding and having the clean surface we applied some stainer to make a good contrast. This is the final result:
(ii) Green mushroom:
For the green mushroom we used the same process, but instead of spray panting it all we used tape in order to make the sanding process faster. This is how the mushroom looks after painting and sanding, respectively:
After sanding we applying some stainer and this is the final result:
In conclusion, we can say that this was a very gratifying assignment and we are really happy with the final results!
“It looks awesome”- Lucas
I hope you have liked our final products and we see you on next post – The Final Assignment!
