Polycarbonate (Lexan)#
Polycarbonate, often called by the brand name Lexan, is a clear, extremely impact-resistant plastic. In FRC it is used for:
- Intake plates and guards that take repeated hits from game pieces.
- Bellypans and panels that protect electronics.
- Flexible or compliant parts where a little give is desirable (it bends instead of shattering).
It is easy to cut on a bandsaw or router, drills cleanly, and can even be scored and snapped for straight cuts. Crucially, it is forgiving of impacts that would crack acrylic or dent aluminum. A common rookie mistake is using acrylic (Plexiglas) instead — acrylic is brittle and shatters; choose polycarbonate for anything that takes a hit.
Cutting and bending tips#
- Drill polycarbonate with sharp bits and moderate speed; it can crack if you force a dull bit.
- It can be cold-bent in a brake or line-bent with a strip heater for clean folds.
- Leave the protective film on while machining to avoid scratches.
Other common materials#
- 3D-printed plastics (PLA, PETG, ABS, nylon, TPU) — fast for prototyping and for non-structural or lightly loaded parts (spacers, brackets, intake rollers). Nylon and reinforced (e.g., carbon-fill) filaments are stronger; TPU is flexible for compliant wheels/rollers.
- Delrin / acetal — a slippery, machinable plastic good for low-friction sliding surfaces and custom gears.
- UHMW — ultra-high-molecular-weight polyethylene, an extremely slick plastic for wear strips and low-friction guides.
- Wood / plywood — invaluable for prototyping mechanisms quickly before committing to metal.
- Rubber/polyurethane tread and compliant wheels — for grip in intakes and on drivetrains.
Choosing a material#
Match the material to the load and the failure mode:
- High structural load → aluminum.
- Impact and abuse, needs to flex not break → polycarbonate.
- Fast iteration or complex shape, low load → 3D print or wood.
- Low-friction sliding → Delrin/UHMW.
Keeping a small stock of polycarbonate sheet, a few filament types, and scrap plywood lets a team build and revise mechanisms quickly.
the part worth keeping
Key takeaways
- Polycarbonate (Lexan) is impact-resistant and easy to cut/bend; use it for intakes, guards, and panels
- Avoid acrylic/Plexiglas for impact parts — it is brittle and shatters
- Use 3D printing and wood for fast prototyping, and Delrin/UHMW for low-friction sliding surfaces
Mechanical, Build & PneumaticsStructure, Materials, and Fastenerslesson 2 of 3
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where this came from
Sources and corrections
This lesson is AI-assisted: drafted from primary sources, then reviewed and edited by hand. Errors still get through. When one is reported we fix it and write down what changed, in public, in the corrections log.
sources and further reading
- docs.wcproducts.comWCP FRC Build System – Hardware & materials
- frczero.orgFRC Zero – Machining & Fabrication
clipped to this lesson
Articles that go further on this
The lesson gets you through the topic. These go wider on it, and they read in one sitting.
- 17 min readFRC Manufacturing and Fabrication: COTS vs Custom, Tools, Materials, and TolerancesHow FRC parts get made: COTS vs custom tradeoffs, shop tools, 3D printing, materials like 6061 and 7075 aluminum and polycarbonate, hole/tap standards, and tolerances./blogread it
- 15 min readHow to Design an FRC Intake: Rollers, Compression, and MotorsA primary-source FRC intake design guide: over-the-bumper vs under-bumper, roller vs wheel, compliance and durometer, compression and wrap, and motor selection./blogread it
- 18 min readFRC Wheels and Traction: Tread, Durometer, and Choosing the Right WheelHow to choose FRC drivetrain wheels: coefficient of friction, Shore A durometer, tread compounds, Colson vs pneumatic vs traction, diameter, and pushing power./blogread it
answer sheet
Lesson quiz
All 3 right completes the lesson. Miss one and only that question comes back, anything you already answered correctly stays banked.
0 of 3 answered
01Why is polycarbonate (Lexan) preferred over acrylic (Plexiglas) for FRC parts that take repeated impacts?
02Which plastic is the best pick for low-friction sliding surfaces and custom gears?
03Which material is best for quickly prototyping a mechanism before committing to metal?
Answer every question to submit.
All 47 lessons in Mechanical, Build & Pneumaticsopenclose
01 / prerequisites
02 / drivetrains
03 / power-transmission
04 / structure-materials-fasteners
05 / mechanisms-fabrication-assembly
06 / pneumatics-fundamentals
07 / pneumatic-components
08 / build-wire-program
09 / safety-rules-testing
10 / worked-examples-mini-projects
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- Not read yet:Mini-Project 3: A Velocity-Controlled Flywheel Shooter
- Not read yet:Mini-Project 4: A Pivoting Roller Intake
- Not read yet:Mini-Project 5: Integrating a COTS Swerve Module
11 / common-mistakes-troubleshooting
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