Build · Design & CAD

Design something that survives contact.

Your first design decision is not the weapon. It’s how fast you can fix the robot between matches. Everything on this page bends toward that.

The design process

Step 1

Define strategy

What do you want your bot to do? Attack, defend, or control?

Step 2

Choose archetype

Pick a proven bot type that matches your strategy and skills.

Step 3

CAD modeling

Design and iterate your robot in 3D before building anything.

Step 4

Validate design

Check weight, printability, and assembly before printing parts.

Combat robot archetypes

Twelve proven bot types. The tag is design complexity — how hard the robot is to engineer and keep running — not a league division or a requirement. A beginner archetype in experienced hands is a podium threat.

Wedge / Pusher

Beginner

Simple armored bot that wins by getting under opponents and shoving them.

Reliable and tough
Excellent ground control
Easy to drive and repair

Vertical Spinner

Beginner

Simple vertical spinner using a disc or a straight bar to flip and damage opponents.

Proven, straightforward design
Easy to drive and control
Good upward bite and toss

Drum Spinner

Intermediate

A rotating drum with teeth that chews into opponents and launches them upward.

More damage per hit
Compact and efficient
Great sustained pressure

Undercutter

Intermediate

Low-mounted horizontal spinner aimed at wheels and undersides.

Targets the ground game and wheels
Very low profile
Difficult to reach

Lifter

Intermediate

Forks or arms raise opponents to control position and neutralize weapon angles.

Exposes weak spots
Strategic control
Anti-spinner forks

Beater Bar

Advanced

A lightweight vertical bar spinning at very high speed for massive single-point hits.

Very energy-dense
Precise balancing needed
Challenging mounting

Horizontal Spinner

Advanced

A horizontal spinner for hard-hitting, chaotic attacks.

Easy to learn, hard to master
Devastating energy
KO potential

Overhead Spinner

Advanced

A horizontal weapon mounted above the chassis to strike top armor in a downward arc.

Targets top panels
Less floor interaction
Pairs well with a ground game

Grappler / Clamper

Advanced

Grabs and holds opponents to shut down weapons and control the pace.

Controls match flow
Denies weapon use
Strong for judges’ calls

Hammer / Overhead Weapon

Expert

Axes, hammers, or saws that strike from above to damage armor directly.

Targeted precision hits
Attacks weak top plates
Combines control and damage

Full-Body Spinner

Expert

The entire outer shell spins, turning the whole robot into a weapon.

360° attack coverage
Hard to approach safely
High intimidation factor

Meme / Fun Bot

Expert

A fun bot that wins the crowd.

Explore unique, impractical designs
Follow an intricate theme
Have fun!

CAD tools (free for students)

Onshape: browser-based, free education accounts, nothing to install, works on a Chromebook. Our default recommendation.
Fusion 360: free personal/education license, richer toolset, needs a real computer.
Tinkercad: genuinely fine for a first wedge. Do not let anyone gatekeep you out of starting here.

Essential design principles

Weight distribution

Keep the center of mass low and central for stability. Heavy components like batteries and motors mount as low as possible in the chassis.

Design for 3D printing

Avoid overhangs greater than 45°, use appropriate wall thickness, and choose print orientation for strength (see the printing guide for the proven profiles).

Serviceability first

Design for quick repairs between matches: removable panels, accessible fasteners, and modular components that swap easily.

Safety integration

Include weapon safety from the start. Weapon locks, a safe power switch, and secure battery mounting are core requirements, not afterthoughts.

Material efficiency

Optimize for the 1 lb limit with hollow sections, removed material, and the right plastic thickness for each component.

Drive system layout

Plan the drive early: gear ratios, motor mounting, wheel placement, and how drive components integrate with the weapon system.

Design-for-repair

Modules, not monoliths. If a wheel mount breaks, you should replace a wheel mount, not reprint the chassis.
Heat-set inserts beat screwing into bare plastic; the fifth disassembly is when you find out why.
The battery is cargo: fully enclosed, no strike exposure, no screws protruding into its bay. That’s a rules requirement and a fire policy.
Print orientation is armor: layer lines perpendicular to expected hits, or the first big impact delaminates the part.

Reference designs

A curated library of downloadable reference CAD is not available yet — it will be announced when files are actually posted. Until then, adapting a proven public design is encouraged: compare any reference against the current construction rules and adapt it for your own components.

Next: 3D printing →The first-build path