Robot Inspection Guide

// Section 01

What Robot Inspectors Actually Check

Inspection is not a gotcha — it is a safety and fairness check. Inspectors are usually experienced VRC volunteers who genuinely want every team to pass. Understanding their checklist means you can self-inspect before you even arrive.

💡

Self-inspect the night before. Every item on the official inspection checklist is public — it is part of the game manual appendix. Teams that work through it themselves the day before an event almost always pass on the first attempt. Teams that skip this step are the ones you see stuck in the inspection line when matches start.

The Six Areas Inspectors Evaluate

Size limits — the robot must fit inside the starting size constraint (18" × 18" × 18" for most seasons) when in its starting configuration. Expandable mechanisms are fine — the robot just has to fit the box before the match starts.
Weight limit — varies by season but typically around 15 lbs. The inspector will put your robot on a scale.
Legal parts only — every component on the robot must be either official VEX hardware, legal 3D printed parts, or explicitly permitted materials per the game manual. No off-brand motors, no modified electronics, no non-VEX structural parts unless explicitly allowed.
Electronics wiring and safety — the V5 Brain, battery, and all cables must be securely mounted. No exposed wiring. No custom circuits or electronics modifications.
Motor count — maximum 8 V5 Smart Motors (11W) per robot. Inspectors may count every motor port in use on the Brain screen.
Pneumatics (if used) — only VEX-legal pneumatic components, reservoir pressure within limits, no modified valves or cylinders.

ℹ️

Read the current game manual appendix. Every season the inspection checklist is published as an appendix to the game manual on RobotEvents.com. The specific limits (size, weight, allowed materials) can change year to year. This guide covers the standard items — always verify the current season’s exact limits before your first event.

When Does Inspection Happen

At most events, inspection opens as soon as the venue opens — usually 30–60 minutes before the first qualification match. You must pass inspection before your robot is allowed to compete. Some events require re-inspection if you make significant mechanical changes during the day.

Plan to arrive early enough to inspect, address any issues, and still have time to connect to the field and verify your autonomous selector before your first match. Arriving at the venue 15 minutes before matches start is not enough time if anything needs fixing.

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// Section 02

Size Limits, Weight, and Legal Parts

The three most commonly failed inspection items. All three are completely preventable with one hour of prep work the day before the event.

Standard VRC Starting Size

🚫

Always verify the current season’s exact limits in the game manual. The numbers below are typical but can change each season. The official inspection form is published with the game manual every year.

18"

Width

Starting configuration only — robot can expand beyond this once the match starts

18"

Length

Measured as the longest horizontal dimension in starting position

18"

Height

Measured to the highest point of the robot including any raised mechanisms

~15 lbs

Weight

Typical limit — verify current season. Includes battery and all attached components

8

Max Motors

V5 Smart Motors (11W). Verified via Brain device info screen

How to Measure Your Robot Correctly

Use a measuring box or a marked-up piece of cardboard or foam. The robot must fit inside the 18"×18"×18" cube with all mechanisms in their starting configuration. Common mistakes:

Forgetting the controller tether cable — if you tether the controller to the brain for autonomous testing, make sure the cable is not extending outside the size limit. At competition the cable is removed, but during inspection it must not be attached in a way that causes issues.
Pneumatic tubes — loose pneumatic tubing that sticks out beyond the robot frame can push the measurement past the limit. Route and secure all tubing before inspection.
Raised mechanisms — an arm or intake that is “stowed” but still slightly raised above the robot body can add inches to the height. Confirm your stow position brings everything within bounds.
License plates — VRC license plates are required on both sides of the robot. They must be clearly visible and the correct color for your team’s alliance. Inspectors will check this.

Legal Parts — What Is and Is Not Allowed

The general rule: structural and functional parts must be official VEX hardware or explicitly permitted materials. The most common legal part categories:

Official VEX metal — C-channels, angles, plates, bars: all legal as purchased
VEX plastic components — all legal as purchased
3D printed parts — legal when used as non-functional structural parts. Must not directly interface with game elements or serve as a mechanism component unless the specific season’s rules allow it. Read R<XX> in the game manual carefully.
Non-VEX fasteners — screws, nuts, and bolts from any manufacturer are typically legal as long as they are standard sizes
Rubber bands, rope, string — legal in most seasons for passive mechanisms
Non-VEX motors — illegal. Only V5 Smart Motors (11W) are permitted as actuators
Modified electronics — illegal. No custom circuit boards, no soldered connections, no modified V5 components
Non-VEX sensors — illegal unless explicitly permitted by that season’s rules

⚠️

When in doubt, ask before you build. Post a question on the Official VEX Q&A on RobotEvents before attaching anything you are unsure about. A Q&A ruling is official — an inspector at an event cannot overrule it. Get the ruling in advance, not the morning of the competition.

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// Section 03

Electronics, Wiring, and Safety

The electronics check is partly a safety check and partly a rules check. Inspectors look for things that could damage the field, other robots, or the V5 Brain itself.

What Inspectors Check on Electronics

V5 Brain is securely mounted — not loose, not held on with a single zip tie. The Brain needs to survive being bumped by other robots.
Battery is secured — must not fall out during a match. At least two points of attachment.
All smart cables are fully seated — click audible when properly connected. Inspectors may tug lightly on cables near the Brain.
No exposed wiring — all cable runs secured with zip ties, no bare wire visible, no crimped or damaged insulation.
Motor count via Brain screen — inspectors will ask you to turn the robot on and navigate to the Device Info screen. Every connected motor will show. Count must be 8 or fewer.
No custom circuits — nothing soldered, nothing custom-wired, no non-VEX electronic components.
Pneumatics pressure (if used) — legal pneumatic systems must use VEX air reservoirs and cylinders. Pressure limits are specified in the game manual. Inspectors may check the reservoir pressure.

✅

Turn on your robot before walking to inspection. Verify the Brain boots correctly, all motors show in Device Info with no red indicators, and your program loads. A robot that does not turn on at the inspection table creates a bad impression and wastes everyone’s time.

The Brain Device Info Screen

Navigate to this screen on the V5 Brain before inspection: Brain Menu → Devices. This shows every device connected to every smart port. What inspectors look for:

All motors show with a green indicator (connected, no faults)
Total motor count is 8 or fewer
IMU, rotation sensors, and other legal sensors are visible and recognized
No mystery devices or error indicators

Wiring That Commonly Fails Inspection

Fails Inspection

Cable draped loose across the floor of the robot
Motor cable stretched tight with no slack
Smart cable connector not fully clicked
Battery held only by friction or one zip tie
Exposed bare wire at a cable end

Passes Inspection

Cables zip-tied to frame at regular intervals
Slack loops at moving joints (arms, lifts)
All connectors clicked with latch engaged
Battery in a firm mount with 2+ attachment points
Cable lengths appropriate — no excess dangling

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// Section 04

What Happens If You Fail Inspection

Failing inspection is not disqualification — it is a correction opportunity. The process is designed to help teams fix problems and compete. Here is exactly what happens and how to respond.

ℹ️

Failing inspection does not prevent you from competing — as long as you fix the issue and pass before your first match. Teams that fail inspection and fix it quickly lose no competitive time. Teams that panic or argue with inspectors lose time and composure.

The Inspection Failure Process

The inspector marks the specific item that failed on the inspection sheet. They will tell you exactly what needs to change — not just “you failed.”
Return to your pit and fix the issue. The inspector will tell you how urgently — if your first match is in 45 minutes, you have time. If it is in 10 minutes, address the most critical issue first.
Return for re-inspection. You only need to re-verify the items that failed — you do not start the entire inspection over.
If you cannot fix it before your match — you may be allowed to compete “under protest” in some cases, depending on the severity of the violation and the event organizer. This is a last resort — do not count on it.

Common Failure Causes and Fixes

Failure	Fix	Time Required
Robot too large	Adjust stow position of the offending mechanism. Retract arms or intakes further. May require repositioning a hard stop.	15–30 min
Too heavy	Remove unnecessary metal, swap steel components for aluminum equivalents in non-structural areas, remove decorative parts.	20–45 min
Loose cable	Add zip ties to secure the cable. Click the connector fully until the latch snaps.	2–5 min
Motor count over limit	This means the robot design itself violates the rules. Remove a motor and rewire. This is a serious design problem that should be caught before the event.	30–60 min
Illegal part	Remove the part. Confirm whether a legal substitute exists. If the part is structural, rebuild that section with legal hardware.	Variable
Missing license plates	Attach license plates to both sides of the robot using VEX license plate clips. Bring spare plates to every event.	2 min

⚠️

Never argue with an inspector during a time crunch. If you believe an inspector’s call is incorrect, politely ask for the head inspector or event coordinator. Do this calmly and after the inspection interaction, not during it. An incorrect ruling can be appealed — but the appeal process takes time, so start fixing the issue while the appeal is being considered.

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// Section 05

Pre-Event Inspection Checklist

Run this the night before every competition. Your progress saves automatically. Every item here mirrors the official inspection form — if all boxes are checked, your robot will pass.

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Size & Configuration

🏆

Bring these to every event: spare license plates (red and blue), spare smart cables in 8" and 12" lengths, zip ties, a flathead screwdriver for port latches, and a small scale if you are close to the weight limit. These five items solve 90% of inspection-line repairs.

⚙ STEM Highlight Engineering: Safety Standards, Compliance & Failure Mode Analysis

Robot inspection is a compliance verification process — the same process used in aerospace (FAA airworthiness), automotive (NHTSA crash standards), and medical devices (FDA 510k). The size constraint (18”×18”×18”) is a design constraint that bounds the solution space. The electrical rules (no modifications to components) prevent single points of failure from unvalidated modifications. Inspection eliminates whole categories of failure modes before competition — a robot that passes inspection has fewer ways to fail catastrophically during a match.

🎤 Interview line: “Robot inspection is a compliance verification process analogous to airworthiness checks in aviation. Each rule eliminates a category of failure mode. The size limit prevents mechanisms from entangling opponents; the electrical rules prevent unvalidated modifications that could fail unpredictably during a match.”

🔬 Check for Understanding

Modifying the internals of a V5 Smart Motor to “improve” performance is illegal in VRC. The engineering reason this rule exists is:

VEX wants to sell more motors

Modified components have not been tested and validated; they may fail in unexpected ways that the unmodified motor’s design would not — violating the verified safety and performance envelope

Modifications always reduce performance

The rule is arbitrary and does not have a technical rationale

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