The first mold is basically a slab with a hole in the shape of an object. This object could be whatever you want it to be. I chose to make the first mold in the shape of a g-clef. I used both Fusion 360 and Inkscape to make this mold. For this method, I found a tutorial on YouTube by LazerLord10 (https://www.youtube.com/watch?v=s0stI95C5Pc). To make this mold, use the following steps:
Open fusion 360 and start a new design.
Go to create -> box
Create a box that is 80mm by 80mm. For the height, go with 10mm.
Go on the internet and find a good quality png of a g-clef (we used: https://pngimage.net/wp-content/uploads/2018/06/g-sleutel-png-6.png).
Open the png file with Inkscape.
Go to path -> Trace Bitmap...
Simply press OK. You have now converted all lines to vectors that Fusion 360 will recognise.
Export the file as a .svg file.
Go back to Fusion 360.
Go to create -> create sketch
Make sure you choose the correct plane, in this case XY.
Go to insert -> insert SVG. A pop-up window will appear in the middle-right of the screen.
Press the small folder-button and choose the .svg file from the location you saved it.
Use the arrows to correctly place the image onto the slab.
Go to finish sketch to exit the sketch editor.
Select the shape as shown in the image below:
17. Press e to open the extrude window
18. For distance, type: -5.00mm
19. You now have succesfully created a mold of your object. You can export your design as an .stl file anywhere on your computer.
Once the designs were finished, we had to print them using the software Ultimaker Cura. In this application, you can import your .stl files. Upon importing a file, you will get a visual representation of the Ultimaker 3D printer. The surface of this visual representation can be seen as the glass plate that is located in the 3D printer itself. Here you can decide yourself where on the glass plate your design will be printed. Since I had four different .stl files (one for the 3D-object and three for the molds), I was worried that I had to perform four different prints. Luckily, Ultimaker Cura allows for multiple files to be imported at the same time, so they will all be printed next to each other. This way, I’d only need to select one file in total to print everything.
Because of the time we had for this assignment, choices had to be made when it comes to the size of the molds and the settings within the application. Below are the settings we used for our print:
When you import the files, they are the size you made them to be within Fusion 360. Pressing “Slice” in Ultimaker Cura allows the application to make an estimate of the time it will take to print the design. With the size the same as in Fusion 360 (8 cm by 8 cm), the printing would take an estimated 16 hours. We did not have enough time for this. So we decided to reduce the size of the molds. This decreased the printing time significantly.
Once you selected the correct settings, you need to export the file to the SD card that is usually inserted into the 3D printer. Take it out and insert it into your own computer to do this. Then insert the SD card back into the printer. From here, select the file from the UI of the 3D printer. The UI is very clear so it shouldn't be a problem to find anything.
Before you can print, you need to make sure the PLA is inserted correctly (polyatic acid is the material that is used to 3D print your objects). Place the roll on the cylinder to the right of the printer. Pull a bit of the PLA towards the small white box behind it. Press and hold the button to insert the PLA at the bottom of this white box. When it's placed correctly, wait for the machine to process the PLA. When it's ready you can press print. The machine will heat up the nozzle before it's ready to go. A bit of excess material comes out first upon starting, carefully remove this.
Unfortunately. our first print failed horribly. The machine had somehow messed everything up. To this day, we still don't know what went wrong. I personally think it could be a case of the machine needing to recalibrate while it was printing our molds. This is just speculation. We tried again and this time everything went well.
We ended up with two very nice molds! We can use these for when we are going to work with bioplastics.
I was lucky enough to come across a tutorial on YouTube to create a two-part mold in Fusion 360. Thijs shared this tutorial in the Whatsapp group chat, props to him! Basically I followed every single step in this tutorial. The only thing I did differently was the design the object inside the mold. The tutorial used a previously created donut. I chose to make a simple object: an hydrogen atom: two spheres that are connected via a cylinder. Using that instead of the donut in the tutorial allowed me to create my own two-part mold.
The tutorial can be found here: https://www.youtube.com/watch?v=vKZx9eHEL6o
