STEM 3D Printing & Maker Spaces 2 — Questions and Answers
Question 1: Which slicing parameter most directly controls the structural strength of a 3D-printed part along the Z-axis?
- Print speed
- Layer height (Correct answer)
- Bed temperature
- Cooling fan speed
Correct answer: Layer height
Smaller layer heights create more bonding surface between layers, increasing Z-axis tensile strength.
Question 2: A student's FDM print has stringing between features. Which slicer setting change is most likely to fix this?
- Increase infill percentage
- Increase retraction distance (Correct answer)
- Decrease layer count
- Increase nozzle temperature
Correct answer: Increase retraction distance
Increasing retraction distance pulls filament back into the nozzle during travel moves, reducing ooze and stringing.
Question 3: In a maker space safety protocol, which personal protective equipment (PPE) is most appropriate when sanding resin SLA prints?
- Safety glasses only
- Nitrile gloves and a dust/respirator mask (Correct answer)
- Heat-resistant gloves
- Steel-toed boots
Correct answer: Nitrile gloves and a dust/respirator mask
Uncured resin particles released during sanding are skin sensitizers and respiratory hazards, requiring gloves and a respirator.
Question 4: Which 3D printing technology uses a UV-curable liquid resin selectively solidified by a light source?
- Fused Deposition Modeling (FDM)
- Selective Laser Sintering (SLS)
- Stereolithography (SLA) (Correct answer)
- Binder Jetting
Correct answer: Stereolithography (SLA)
Stereolithography (SLA) cures liquid photopolymer resin layer by layer using a UV laser or light source.
Question 5: An educator wants students to practice iterative design. Which maker space workflow best supports this?
- Print once, evaluate at the end of the unit
- Design, print, test, and redesign in rapid cycles (Correct answer)
- Finalize CAD files before printing anything
- Use only pre-made templates to avoid errors
Correct answer: Design, print, test, and redesign in rapid cycles
Iterative design cycles (design-print-test-redesign) teach engineering practice and reinforce the design process standard.
Question 6: What does 'infill pattern' refer to in FDM slicing software?
- The outer shell thickness of a print
- The internal geometric structure that fills the inside of a printed object (Correct answer)
- The number of top and bottom layers
- The temperature setting for the print bed
Correct answer: The internal geometric structure that fills the inside of a printed object
Infill pattern describes the internal geometry (e.g., grid, honeycomb, gyroid) used to fill the solid interior of a print for strength and material efficiency.
Question 7: Which material property makes PLA the most common choice for classroom 3D printing compared to ABS?
- Higher heat resistance
- Lower printing temperature and minimal warping (Correct answer)
- Better chemical resistance
- Greater flexibility
Correct answer: Lower printing temperature and minimal warping
PLA prints at lower temperatures (~200°C vs ~240°C for ABS) and requires no heated enclosure, making it safer and more reliable in classrooms.
STEM 3D Printing & Maker Spaces 2
Which slicing parameter most directly controls the structural strength of a 3D-printed part along the Z-axis?