What is CAD?#
CAD stands for Computer-Aided Design. In FRC, it means building a complete, accurate 3D model of your robot on a computer before you cut a single piece of metal. Every tube, plate, gear, motor, bearing, and bolt exists in the model, positioned exactly where it will go on the real robot.
Modern FRC CAD is parametric, which means the model is built from a recipe of features (sketches, extrudes, holes) driven by dimensions. Change one dimension and the model updates everywhere it matters. This is what lets a designer say 'make this gearbox plate 0.125 in thicker' and have the whole assembly stay correct.
Why bother? The build season is short#
FRC gives teams roughly six to eight weeks from Kickoff to their first competition. Building the wrong thing wastes irreplaceable time and money. CAD lets you:
- Catch interference before you cut metal. The software flags when two parts occupy the same space, when a motor won't fit, or when a bolt has no clearance.
- Check the rules. You can verify your robot fits the legal envelope. For 2026 REBUILT, rule R104 says the robot's starting configuration may not have a ROBOT PERIMETER greater than 110.0 in and may not be more than 30 in tall; R103 caps weight at 115.0 lb without bumpers and R408 caps it at 135.0 lb with bumpers.
- Plan manufacturing. A finished model produces a parts list and drawings so the build team knows exactly what to make and buy.
- Communicate. A 3D model is the single source of truth that mechanical, electrical, and programming sub-teams all reference.
CAD is part of a bigger process#
CAD does not start at Kickoff. It comes after your team has analyzed the game, picked a strategy, and prototyped key mechanisms. CAD turns a proven prototype concept into a precise, buildable design. Treat the model as a living document: as prototypes teach you things, you update the CAD, and as you CAD, you discover constraints that send you back to prototyping.
A realistic FRC CAD workflow#
- Strategy and prototyping decide what mechanisms you need.
- A layout sketch lays out the major dimensions and how subsystems fit together.
- Designers model each subsystem (drivetrain, intake, scorer) as parts and assemblies.
- COTS parts (motors, gearboxes, wheels) drop in from libraries.
- Drawings and a bill of materials feed manufacturing and purchasing.
- Design reviews catch problems before anything is built.
Learn this loop and you become the person who turns ideas into a robot.
A great starting point is the free FRCDesign.org Learning Course, built by experienced FRC CAD mentors.
the part worth keeping
Key takeaways
- CAD is a parametric 3D model of the entire robot built before manufacturing, used to catch problems, check rules, and plan the build
- The short FRC build season makes designing-before-building essential, not optional
- CAD follows strategy and prototyping; it turns a proven concept into a precise, buildable design
- The 2026 REBUILT rules define the legal envelope your CAD must respect: R104 sets a 110 in perimeter and 30 in height; R103/R408 set 115 lb (no bumpers) / 135 lb (with bumpers)
CAD & DesignGetting Started: CAD Software and the Design Processlesson 1 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
- frcdesign.orgFRCDesign.org Learning Course
- frcmanual.com2026 Game Manual — ROBOT Construction Rules
clipped to this lesson
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The lesson gets you through the topic. These go wider on it, and they read in one sitting.
- 20 min readBuilding an FRC Scouting App: Data Model, TBA/Statbotics APIs, and PicklistsBuild an FRC scouting app: match and pit scouting, a simple data model, pulling schedules and EPA from the TBA and Statbotics APIs, and building a picklist./blogread it
- 8 min readFRC Build Season Timeline: A Week-by-Week Plan from Kickoff to CompetitionA practical week-by-week FRC build season timeline, from Kickoff and game analysis through prototyping, CAD, fabrication, wiring, programming, and driver practice./blogread it
- 4 min readThe FRC Robot Design Process, Step by StepA clear, beginner-friendly walkthrough of the FRC robot design process, from game analysis and strategic prioritization to prototyping, CAD, and iteration./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
01What is a primary reason FRC teams CAD their robot before fabricating parts?
02How does a finished CAD model help an FRC team plan manufacturing?
03Why is a shared CAD model valuable to an FRC team as a whole, beyond a single designer?
Answer every question to submit.
All 31 lessons in CAD & Designopenclose
01 / prerequisites
02 / getting-started-cad-and-the-design-process
03 / onshape-fundamentals
04 / vendor-libraries-mkcad-featurescripts
05 / manufacturability-drawings-bom-design-reviews
06 / worked-examples-mini-projects
07 / common-mistakes-troubleshooting
- Not read yet:Mate & Assembly Failures: Why Parts Float, Spin, or Won't Move
- Not read yet:Broken In-Context & Derived References
- Not read yet:Slow Regeneration in Big Drivebase Assemblies
- Not read yet:Manufacturability Mistakes That Become Scrap
- Not read yet:Version Control & Team Collaboration Disasters
08 / advanced-techniques-case-studies
- Not read yet:Configurations vs. Parametric Variables: Designing One Model, Many Robots
- Not read yet:FeatureScript Automation for FRC
- Not read yet:Browser-Based FEA: Weight-Optimizing Real Structures
- Not read yet:Swerve System Geometry & Motion Math
- Not read yet:Case Study: FRC 6328's Modular Gusset-and-Tube Methodology