Week # 3
Ideation
Tell us about your assignment's idea for this week. Why do you care about this idea? What inspired you? (Please include images or links to sources of inspiration)
This week's assignment is to Design and fabricate a 3D printed model of a pen and pencil holder that may rest on a flat surface, using the Fusion 360 and the 3D design features (Revolve, Sweep, Loft, sub-features), and the final model doesn't exceed 30 grams or up to 90 minutes
I developed the idea after browsing some projects on the internet, I liked the general concept of a shell based holder like the one represented in this Image, yet I had some doubts regarding the printing possibility of such shape without supports may fail, so I simplified the idea to a more solid surface
Tool Chain
Which software/machines/materials did you use in the assignment? Why?
Software Used for Design, assembly and creating .dxf file: Fusion 360
Software used for preparing .gcode file for 3D Printer: Ultimate Cura
Machine: PRUSA i3 MK2 3D Printer
Material: Filament PLA 1.75 mm
Preparation Process
Explain the design and/or preparation process of your assignment. How did you use the tool or software to design and/or prepare your assignment before fabrication/implementation?
First I designed a sketch for the shell cross section as a part from a circle, with a base to hold the pens from falling and to act as a base in the printing process
then using the revolve tool to transform it to a shell
I changed the appearance of the body to match the final required finishing of red plastic
then, using an offset plan at the top point of the shell I draw a rectangle to use as a base for the next step, which was the Hole feature with a diameter of 12mm (a little bigger than a normal pen's) and with depth long enough to cut through the shell
then using the pattern too I repeated the "Hole Feature" along one side for 2 additional holes for an angle of 60 degrees,
using the pattern again for repeating the "Hole Feature" for the 2 new holes 5 times along the vertical axe
and using the same method again, I created 5 additional holes on a different angel to in the inner spaces between holes
and for making a lower guide for the pens to fix them in location and reduce rotation, I decided to make another set of holes on the lower surface, using sketch I draw 2 circles and also by using circular pattern I repeated them
finally using Extrude tool I cut these holes throw the lower surface
the final design
a section cut on the final design
After saving the body as .stl file, I used Ultimaker Cura software to prepare the file with the printing parameters
I used 0.3 Profile, 10% infill, without adhesion as the design already have a large bottom surface area, and without supports as the sphere shape is solid enough and the holes aren't wide, the shape will support itself.
the Slicing resulted in 84 min of printing and 18 gm
Finally I saved the file as .gcode file to be ready for printing
Development/Implementation Process
Explain the development/implementation process of your assignment. How did you use the machine/tool to manufacture or implement the design of your assignment?
After saving the file as .gcode file to be ready for printing I loaded it on the machine's memory card, inserted it into the 3D printing machine, then with the help of the lab specialist we changed the PLA Filament to the Red color, then I selected the file and started printing
20220202_120814_1.mp4The Final The Final Outcome
Community of Learning
Did you ask for feedback? What are the ideas that others have contributed or suggested? What was someone else’s idea that you built upon? How did you help your peers? How did your peers help you?
the design process went through multiple sketching trials, and multiple slicing trials, because I exceeded the time and weight limits, my original design consisted of 2 shells, inner and outer as shown in the below images, I had to try the 0.6 & 0.4 profile heights and after discussing with the instructors they recommended to change the scale, and not to exceed 0.3 profile to achieve the best quality
But I didn't want to scale the design on Cura to avoid reducing the openings sizes, so I had to modify the sketches and the original design multiple times, I reduced the shell thickness from 3mm to 2mm, I removed the inner shell, and even reduced the height from 55 mm to 45 mm, until I finally could fulfill the time and weight limits
Overcoming Challenges
When you got stuck, what/who did you turn to? At what point did you have to pause to research or learn more before moving on? What are some mistakes, pitfalls, or challenges that others can avoid if they were doing this assignment?
1-When using the Hole feature on the surface of the sphere, I couldn't make any straight vertical holes, as there was no snapping at all,
after some searching, I found recommendations to draw a surface first according to the required hole, and then use the feature
so I draw a rectangle on a sketch on an offset plan at the top center of the sphere and used it to apply the hole feature which worked fine
non vertical hole feature on the shell surface
perfect vertical hole feature after snapping on the sketch
2- While using the 3D printer, and after about 5 min, the printer stopped working with an error of "Thermal Runaway", which was explained to me by the lab specialist as the temperature of the printing is falling down, either because a malfunction or because the thermal sensor isn't reading the correct temperature
So we tried printing again, and also after a few minutes the temperature started to fall down again, this time another specialist suggested to slow down the fan speed, which helped solving the problem and the printer continued
Failed first trial
Temperature falling down to 197/210, which will lead to the error
Temperature stable
Final Project
How can you use the skills and knowledge that you've acquired this week in your final project?
This weeks assignment specially the process of redesigning to fulfill the time and weight limits improved my sense of weight, scale and dimensions of the final outcome, and since my final project will require multiple 3D printed parts (gears, supports and rail holders) I believe I can use the lesson learned from this assignment to reduce the time needed for printing and even save some time in designing sketches in the first place
WOW!
What is the coolest thing that you've learned this week? What is something that you will never forget from this week?
The coolest thing I learned this weak was that I can get an estimate weight of the bodies designed on Fusion 360 without even sending it to slice in Cura software, maybe it isn't valid for any body created but at least for solid bodies,
I found that the volume of the body can be calculated by Fusion and appears under properties, and after some searching about the density of the PLA material I found it to be 1.25 g/cm3, so by a simple calculation the body mass can be found,
and even to avoid calculation, I tried to find the PLA material that can be assigned on the body in fusion, but I couldn't find it, so I assigned Plastic material and changed it's density according to steps described here which resulted in almost the same mass as estimated by Cura with 100% infill,
and by that I can find an estimate weight for the parts directly from fusion and can then edit my sketch and design and reduce the time needed for slicing every design trial, and of course the resulted mass will be reduced according to the infill % which may be estimated to around 20%
