3D Printing
In this page, I will go through the steps I took to create a product that cannot be easily made by subtractive manufacturing.
Before that, lemme explain what subtractive manufacturing is.
Simply, subtractive manufacturing is the process of manufacturing a product by removing material through machining processes. An example of subtractive manufacturing is an ice sculpture, where the ice is picked and chiseled into a new form.
Before I can 3D print anything, I must have a CAD drawing of the product I want to print. The prodcut I have made is a hinged box. I will explain why it is difficult to make by subtractive manufacturing later in this blog.
1. Upon opening Fusion360, I selected "Box" under the "CREATE" section.
2. I then selected the top view plane.
3. Starting from the origin, I created a box that is 50mm by 50mm by 50mm.
4. I then selected "Sketch" under the "CREATE" section and selected the front face of the box.
5. From the midpoint of the right length of the face of the box, I drew a horizontal construction line by using the "L+X" command. The length of the line does not matter, I just made it long enough for me to complete the next step.
6. Using the center diameter circle command "C", I created 3 circles with the same center point but different sizes.
7. Using the sketch dimension command "D", I clicked on the smallest circle and gave it a 3mm diameter. I then gave the distance between the circumference of the smallest circle to a bigger circle a value of 0.2mm. Next, I set the distance between the outer circle and the largest circle a value of 3mm.
8. I sketched another dimension for the distance between the center of the circles and the length of the box as 5 mm.
9. Starting from the length of the box, I drew 2 lines that are tangent to the largest circle.
10. Next, I sketched the dimension of the angle between the tangents and the length of the box to be 45 degrees.
11. I then clicked "FINISH SKETCH".
12. Under the "CONSTRUCT" section, I clicked "Midplane".
13. I then selected the top and the bottom faces of the box to create the midplane.
14. Under "MODIFY", I selected "Split Body".
15. To split the body, I first selected the box, then clicked on "Splitting Tool(s)" and clicked on the midplane.
16. I renamed the 2 newly created bodies "Top" and "Bottom"
17. Under the "Bodies" browser, I hid the top body and keep the bottom body visible for better visibility.
18. Using the extrude command "E", I clicked on the bottom wing, the knuckle, the pin, and the gap between the pin and the knuckle and extrude it -9.5mm. I also made sure the "Operation" is "Join".
19. I repeated step 18 for the opposite end of the face of the cube.
20. Next, I extrude the pin(smallest circle) to the opposite face of the box. I also madde sure that the "Operation" is "Join".
21. Now, I hid the bottom body and reveal the top body.
22. I extruded the top wing and the knuckle with and offset of -10mm and a length of -30mm.
Sidetrack...Now this is what makes my product difficult to make with subtractive manufacturing. Looking at steps 20 to 22, it is seen that the knuckle is made around the pin, where there is a very small gap of 0.2mm. In order to create this gap using subtractive manufacturing, one would need more than surgeons precision to carefully remove material between the pin and the knuckle. And even if someone had that precision, there isn't any space for tools to fit in and carve out the gaps between the pin and the knuckle. Anyways, back to the process!
23. I then reveal both bodies.
24. On the timeline found at the bottom of the screen, I dragged the vertical handle between the "Sketch" and the "Box" icons.
25. Under "MODIFY", I selected "Shell" and selected all 6 faces of the box and gave it an inside thickness of 3mm.
26. I then dragged back the vertical handle on the timeline all the way to the right to reveal the finished drawing of the product.
Now to fix the orientation to make it optimal for 3D printing.
27. Under "ASSEMBLE", I selected "New Component", clicked on the the checkbox for "From Bodies" and selected the top and the bottom body.
28. Next, under "ASSEMBLE", I selected "Joint".
29. For component 1, I hid the bottom body and selected the center of the knuckle.
30. I then revealed the bottom body and hid the top and selected the center of the pin.
31. Upon completing step 30, the top body will be dislocated, thus I used the slider to drag the body back to its position. I also rotated the top body to 180 degrees to make it easier and faster to print the box.
Now to slice it!
32. Under the "TOOLS" tab, I selected "3D Print" under the "MAKE" section, select the entire product(in my case, it's "(HingedBox v3)") and deselect the checkbox for "Send to 3D Print Utility" and clicked "OK".
33. This prompts me to save this .stl file which I renamed as HingedBox.
34. I then opened up Ultimaker Cura by locating the saved .stl file named "HingedBox" on my computer and changed the printer to "Creality Ender-3".
35. I set the quality to "Low Quality", changed the "Infill Density" to 50% and the "Infill Pattern" to "Cubic", set the "Build PLate Temperature" to 60.0°C, "Print Speed" to 70.0 mm/s, select "Generate Support" and set "Build Plate Adhesion Type" to "None".
These settings are optimal for my product because it is a cube and does not require much detail.
36. I clicked "Slice" and found out that my estimated printing duration is 4 hours and 22 minutes. This is because my product is too big.
37. I clicked on the product and changed the scale to 60% scale with "Uniform Scaling" checked. This gives an estimated time of 1 hour and 8 minutes which should be fine.
38. I saved this to a removable disk which would then be used on the 3D printer for it to print the product.
This is how the product looks like!
.f3d File Link:
.stl File Link:
And here is a photo of me and my product!
As I was tasked to create a product that is difficult to make by subtractive manufacturing, I also found it difficult to come up with creative unique ideas. Thus, I had to go with one of the examples given which is to make a product that uses a hinge. And so, I made a hinged box.
The task was really interesting because we were given a restriction which is that the print time should be around 1 hour. This makes it difficult to make products of a large size. Theoretically, if this time limit didn't exist, I could make a multitude of things that fulfills the requirements of being difficult to make by subtractive manufacturing.
I used to think that 3D printing has a very long process and requires much skill and money in order to create something. Now, with the CAD skills I have, I think that 3D printing is not out of my reach anymore and I think it can be a fun hobby, although it may also be costly. So next I will try to spend as much time on a 3D printer in campus to create interesting products for my own safekeeping as well as for my upcoming FYP next year.
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