Week 4 · Journal — HTMAA 2025

This is the class I have been waiting for and was the main reason why I signed up for this course. I could print a few objects I made in the parametric design session in week1, but to make things a bit interesting, and also test the different physical properties of different filament, I decided to go light on the design and just run some experiments this week

Goals: 3D Print something that cannot be made subtractively, and 3D Scan something

3D Print 1- (TPU) Phone case:

First, I chose TPU to print a phone case that I hope I could actually use on my iPhone 16 Pro Max.

The file was in STL format and cannot be printed directly. It needs to go through a slicer software and export to G-Code(Pretty Much instructions to tell the 3D printer how to print layer by layer)

Nice phone case with cutout to minimize the weight

The phonecase looks Ok, but since it is TPU and soft, the case edges do not have enough "grip". It would fall off the phone. To make it work I need to make the case "tighter" and probably adjust the structure a bit.

3D Print 2- (PLA)Anime figurine:

**Frieren and Mimic** I'm thinking of 3D priting a figurine of this.

I found this nicely crafted STL file of one of my favorite anime character. Frieren and the Treasure Chest Monster(Mimic). The first print failed however. Jesse told me for this print I better use organic support.

The organic support make it look really creepy

3D Printer Setting:
Layer height: 0.10 mm
Filament: PLA
Infill: 10% (5% should be fine too)
Support: Everywhere, Organic Style

Tear down the support easily takes an hour..

3D Scanning: I experimented on two materials. One stuffed toy with a lot of fur and a figurine.

Both worked surprisingly well. The figurine was missing part of the face, likely because the lighter color reflected the scanner differently.

Some Reference/Notes

Filament Types:
PLA:Hard,Biodegradable, suitable for figurines, models, prototypes
PETG:Similar to PLA but stronger
TPU:Rubber-like flexibility, suitable for cases, seals, dampers

File Type:
STL:Common, highly compatible, but only geometry info no unit of color data
PLY:Originally for 3D scanning, can store color data, larger than STL
AMF/3MF:Designed to replace STL, smaller file size with color and unit data
G-code:The low-level programming language used to control 3D printers and CNC machines; it specifies movement, temperature, and other instructions.

3D Printers should be placed in rooms with good ventilation as it releases UFPs(Ultrafine Particles)

Safety comes first! Table of filaments that may need ventilation

Filament	Ventilation Needed?	Notes
ABS	Yes	Releases styrene fumes; strong smell; use enclosure + ventilation.
ASA	Yes	Similar to ABS; styrene emissions; proper ventilation required.
Nylon (PA)	Yes	Emits caprolactam; can irritate eyes/throat; ventilate well.
Polycarbonate (PC)	Yes	Produces BPA and strong fumes; needs enclosure + ventilation.
TPU / TPE	Recommended	Generally mild fumes; additives vary; ventilation helps.
PETG	Recommended	Low emissions but not zero; airflow improves safety.
PLA / PLA+	No	Very low emissions; safe for indoor use; minimal odor.
PLA blends (Silk, Wood, Glitter)	No	Same safety profile as PLA; low emissions.

Week 4 — 3D Printing and Scanning

Safety comes first! Table of filaments that may need ventilation