Pass first. Then weigh in.
Structural qualification is pass/fail. Among the structures that pass every requirement, the lowest total assembled mass wins.
POE Unit 0 • Lesson 0.9
Fabrication & Assembly
Focus question: How do accurate fabrication and M3 assembly choices affect the final mass and structural integrity of the CubeSat?
Challenge Rules
CubeSat Lightweight Structure Challenge
Every team works inside the same architecture and material limits. Your engineering advantage comes from how efficiently you use them.
- Maximum assembled envelope: 4 in × 4 in × 4 in, including hardware.
- Top and bottom: laser cut from the team’s single 4 in × 12 in × 1/8 in acrylic sheet.
- Sides: remain open; no side panels.
- Primary frame: 3D printed using the same teacher-selected filament material for every team.
- Assembly: M3 screws for all primary structural connections; structural glue is not permitted.
- Serviceability: the structure must be able to be disassembled and reassembled with normal hand tools.
- Competition: the lightest structure that passes every qualification requirement wins.
Lesson Targets
What You Will Be Able to Do
I can manufacture and assemble the CubeSat safely, check fit and alignment, and produce a complete competition-ready structure.
Hand Tools Certification + completed CubeSat structure
The CubeSat is fully assembled with M3 screws, remains within the 4-inch envelope, has open sides, and is ready for qualification.
Activity Flow
How Today Advances the CubeSat
1. Inspect manufactured parts
Check dimensions, holes, print quality, and acrylic edges before assembly.
2. Assemble with M3 hardware
Use the planned fastener sequence and correct hand tools.
3. Complete pre-competition inspection
Verify size, open sides, secure joints, and total assembly readiness.
Assembly Quality
Mass Is Not the Only Thing That Can Disqualify a Design
Fit
Do not force mismatched holes or printed parts. Diagnose tolerance problems before tightening hardware.
Fasteners
M3 joints should be secure without crushing acrylic or stripping printed connection features.
Alignment
Top and bottom plates should remain aligned and the structure should sit squarely without obvious twist.
Project Milestone
Today’s Required Deliverable
Completed CubeSat Prototype
- Hand Tools Certification completed.
- Laser-cut acrylic top and bottom installed.
- 3D-printed structural frame installed.
- Primary structural connections use M3 screws.
- No structural adhesive used.
- All four sides remain open.
- Assembly can be disassembled and reassembled.
- Team performs a final 4-inch envelope check before competition day.
Engineering Decision
Document the Reasoning
What did your team decide today?
What measurements, requirements, comparisons, calculations, or manufacturing information support that decision?
Why does that evidence make the decision appropriate for a lightweight structure that still has to qualify?
Resources
Lesson Resources
Hand-Cutting Tools Certification
Complete the relevant hand-tool certification before final fabrication and assembly work.
CubeSat Unit 0 Overview
Review the complete challenge sequence, project rules, deliverables, and competition objective.
Principles of Engineering
Return to the POE hub for units, course resources, and certifications.