The mindset#
Most matches are lost to reliability, not strategy. A robot that does one thing every match beats one that does three things sometimes. This lesson converts the prior failure modes into proactive habits.
The pre-match pit checklist#
Run this before every match:
- Battery: charged, >12.5 V resting, securely strapped, and the main Anderson connector tight, loose battery leads cause brownouts.
- Fastener audit: wrench-check drivetrain, gearbox, and superstructure bolts. Re-seat anything backing out.
- Pneumatics: charge the system, confirm the high side reaches system max and the regulated low side reads ~60 PSI, listen for leaks, and confirm the system holds with the compressor off.
- Bumpers: within the legal mounting zone, numbers visible, hardware tight.
- CAN/wiring: tug-test motor controller and CAN connectors; a wiggled CAN wire drops a device mid-match. Confirm no flashing fault LEDs.
- Mechanism dry-run: in the pit, cycle every mechanism through its range and watch for binding or odd current draw.
Spare-parts kit (bring duplicates of failure-prone items)#
- A charged spare battery (always more than one).
- Spare motor controllers and a spare motor of each type used.
- Pneumatic fittings, tubing, and a spare solenoid.
- Hex shaft stock, hex bearings (1/2 in hex), sprockets/belts, and assorted fasteners + nylocks.
- Blue threadlocker, zip ties, electrical tape, and spare Anderson connectors.
CAN and wiring discipline#
- Strain-relieve every connector so vibration can't unseat it.
- Keep CAN runs away from sharp edges and moving mechanisms; a pinched CAN wire kills the whole bus downstream.
- Label CAN IDs and keep a wiring map in the pit. (Remember: PDP and legacy CTRE PCM at CAN ID 0.)
Triage during an event#
When something breaks between matches: reproduce it, look at the failed part to read the root cause (per the gearbox/fastener lesson), apply the matching fix, and re-test the full cycle before queueing again. Don't ship an unverified fix to the field.
After the event#
Keep a reliability log: what broke, the root cause, and the permanent fix. Teams that log failures stop repeating them season over season.
the part worth keeping
Key takeaways
- Reliability wins matches: run a fixed pre-match checklist covering battery, fasteners, pneumatics, bumpers, CAN/wiring, and a mechanism dry-run.
- Carry a spare-parts kit (extra batteries, motor controllers, fittings, hex shaft/bearings, threadlocker) for fast pit repairs.
- Strain-relieve and route CAN/wiring away from moving parts (PDP/PCM at CAN ID 0), and never send an unverified fix back to the field.
Mechanical, Build & PneumaticsCommon Mistakes & Troubleshootinglesson 5 of 5
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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
- team5026.comIron Panthers: How to Design Robust FRC Robots
- frczero.orgFRC Zero: Pneumatic Troubleshooting
- firstinspires.orgFIRST Robotics Competition Game & Season Materials
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.
- 7 min readFRC Pit Checklist and Competition Packing List (Printable, 2026)A complete, printable FRC pit and competition packing list — tools, spares, batteries, safety, laptop/software, paperwork — plus a robot self-inspection pre-check mapped to the 2026 rules./blogread it
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- 9 min readFRC Pneumatics: How to Design, Wire, and Program a Pneumatic SystemComplete FRC pneumatics guide: components, the REV Pneumatic Hub vs PCM, single vs double solenoids, safe wiring, WPILib programming, and the 60/120 psi limits./blogread it
answer sheet
Lesson quiz
All 4 right completes the lesson. Miss one and only that question comes back, anything you already answered correctly stays banked.
0 of 4 answered
01In the pre-match pit checklist, how should the battery be prepared before a match?
02What does the pneumatics step of the pre-match checklist ask you to verify?
03Why is it important to strain-relieve and carefully route CAN wiring?
04When something breaks between matches, what should you do during event triage?
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
- Not read yet:Mini-Project 1: A Single-Jointed Arm From Math to Motion
- Not read yet:Mini-Project 2: A Two-Stage Cascade Elevator
- 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
- Not read yet:Pneumatics Won't Fire: A Full Diagnostic Tree
- Not read yet:The Robot Won't Drive Straight (and Other Drivetrain Sins)
- Not read yet:Gearboxes That Grenade and Fasteners That Vibrate Loose
- Not read yet:Closed-Loop Mechanisms That Oscillate, Sag, or Stall
- Not read yet:Field-Ready Reliability: Inspection, Spares, and the Pit Checklist
12 / advanced-techniques-case-studies
- Not read yet:Characterizing Any Mechanism with SysId
- Not read yet:Simulation-Driven Design with WPILib Physics Models
- Not read yet:Motion Profiling and Superstructure Coordination
- Not read yet:Designing for Weight, Stiffness, and Manufacturability
- Not read yet:Case Studies: Learning From Open Alliance Robots