Back

Session 3: Additive Manufacturing

Unit 2 — Manufacturing Foundations, Week 1

divider

Session 3

Additive Manufacturing

Two Ways to Make a Part

Session 2 was all subtractive — start with material, cut away everything that isn't the part.

Today's process does the opposite: start with nothing, and build the part up.

How FDM Actually Works

Filament — a spool of solid plastic — feeds into a heated nozzle.

How FDM Actually Works

The nozzle melts it and deposits it in a thin path, one layer at a time, bottom to top — following a 3D model that's been "sliced" into hundreds of flat layers.

Three Common Filaments

PLAPETGABS
Ease of printingEasiestModerateHardest
Strength/toughnessRigid, brittleTougher, less brittleStrong, impact-resistant
Heat resistanceLowModerateHigh
Warping riskLowLow–moderateHigh — often needs an enclosure

Slicer Vocabulary

Layer height — thinner = smoother surface, but slower to print.

Slicer Vocabulary

Infill — most prints aren't solid inside. A percentage and pattern fill the interior — more infill means stronger, heavier, and slower.

Slicer Vocabulary

Supports — temporary scaffolding printed under overhangs that would otherwise droop mid-print, removed once printing is done.

Orientation Changes Strength

Layers bond well to the layer below them, but not nearly as well when you try to pull them apart sideways.

A part printed the wrong way up can look identical and still snap under a load a differently-oriented print would survive.

Your Printer

Dremel's education printers are FDM machines with a heated bed and an all-metal hotend.

Your Printer

[VERIFY] — confirm your specific model's exact build volume, max nozzle/bed temperature, and which materials it's actually rated for before relying on any of that in a real design.

So When Do You Print Instead of Route?

Three questions to ask about any given part:

Question 1

Is it a large, mostly flat shape — or small and geometrically complex?

Question 2

Does it need to bear real structural load, or just hold its own shape?

Question 3

Do you need it fast and cheap in sheet form, or is one custom-fit piece worth the print time?

Neither Answer Is "Better"

A large flat side panel and a custom joystick bezel have different answers to all three questions — that's exactly why this project uses both processes.

Two Things to Remember

Print orientation is a real design decision.

Decide it based on how the part will actually be loaded, not whatever orientation looks easiest to print.

Two Things to Remember

Additive doesn't replace subtractive here — it complements it.

CNC/CAM stays the required, safety-gated core skill of this unit. Printing is a real option for the right part, not a shortcut around learning CAM.

Next Time

Session 4: CNC Safety Certification

Before anyone touches the router, the hard gate this whole project runs through.

'F' → Fullscreen

divider

Build

Step 1: Filament Comparison

PLAPETGABS
Ease of printingEasiestModerateHardest
Strength/toughnessRigid, brittleTougher, less brittleStrong, impact-resistant
Heat resistanceLowModerateHigh
Warping riskLowLow–moderateHigh

Step 2: Route It or Print It?

For each arcade cabinet component below, decide subtractive (CNC-routed sheet material) or additive (3D printed), and justify with at least one of the three questions from today's slides — not just a guess.

  • Side panel
  • Joystick/button mounting bezel
  • Marquee light mount bracket
  • Control panel base
  • Cable management clip

Step 3: Propose Slicer Settings

For whichever component above you chose to 3D print, propose a layer height, an infill percentage, and whether it needs supports — and justify each based on what that specific part actually needs to do.

divider

Checkpoint

Before you move on, check your work against these two questions.

Did you justify with a real property?
"Because printing is cool" isn't a justification — point to geometry, load, or quantity/cost instead.
Did you consider orientation for any printed part that bears load?
A bracket or mount that holds real weight needs its print orientation reasoned about, not left to default.
divider

Reflection

Answer the following questions before submitting your work.

  1. Which arcade cabinet component are you most confident should be 3D printed, and why?
  2. Is there a component where you're genuinely unsure whether to route or print it? What information would help you decide?
  3. Session 4 begins hands-on machine work. Which process — subtractive or additive — do you expect your team to actually use more during the real build in Weeks 5–8?
divider

Submit

Submit your route-or-print decisions with justifications, your proposed slicer settings, and your reflection.

Activity Complete