Maryland FIRST RoboticsRepairing Robots Fast Without Burning the Team
Robot repairs under time pressure at a competition become manageable when everyone knows what to check, who can authorise a change, and when a safe working machine is better than a perfect one. The match clock still matters, but rushing around the pit creates more mistakes than it prevents.
The challenge starts long before the first match. Teams that wait for a breakdown to reveal their readiness usually discover missing tools, untested spare parts and unclear roles at the worst possible moment. A repair plan turns an improvised scramble into a sequence of small, controlled decisions.
Success also depends on the person holding the tools. Experienced mentors can model calm diagnosis, newer students can practise fault isolation, and volunteers can keep the work area safe. The aim is not to make every student an electronics technician; it is to give each person a useful responsibility when something fails.
This discipline supports teams across FIRST LEGO League, FIRST Tech Challenge and FIRST Robotics Competition, from early builds to advanced prototypes. Whether the robot uses a simple drive chassis or a complex lift and vision system, the same principle holds: protect people, preserve legal functionality, and recover quickly enough to compete.
Establish priorities before the clock starts
Write a one-page triage hierarchy and put it beside the pit workbench. The first priority is safety: isolate power when a fault involves wiring, smoke, impact or an unexpected movement. The second is legal, dependable movement. The third is performance that improves scoring. Cosmetics wait until the robot can compete safely and consistently.
Assign a repair lead, a test operator and a recorder. One person changes the robot, one runs controlled tests, and one logs symptoms and changes. This prevents three people from making conflicting adjustments to the same mechanism. Brief substitutes before each event so an absent mentor does not create a single point of failure.
Set a decision deadline for every repair. If a quick check does not identify the fault, move to the next likely cause rather than repeatedly replacing working parts. When the match queue closes, the repair lead decides whether to return the robot, use a spare machine if the event rules allow it, or withdraw it. That decision protects the rest of the schedule and the team’s remaining matches.
Prepare a repair kit and a test bench
A repair kit should be organised by failure mode, not by whoever happened to pack the toolbox. Keep spare motors, speed controllers, servos, distance sensors, encoders, wire, crimp pins, connectors, zip ties and commonly used fasteners in labelled bags. Photograph each bag and its wiring diagram so a student can find the right item without waiting for a senior mentor.
The bench should include a laptop with the required software, a charged battery, a multimeter, insulated tools and known-good modules. Label battery states and keep one connector of each type ready. Run the bench after every practice so a charged battery never means an untested charger.
Use the comparison below as a decision guide during a match queue or preparation period.
| Observed problem | Fast check | Low-risk response | Escalate when |
|---|---|---|---|
| Loose or damaged wiring | Trace the route from controller to motor and inspect a disconnected connector | Reseat the connector, replace the lead and reroute it clear of moving parts | The controller reports repeated faults or insulation is damaged |
| Motor does not respond | Check command, encoder feedback and power at the output | Swap with a known-good motor or controller port, then test in isolation | Both sides fail or the controller becomes warm |
| Sensor reads incorrectly | Confirm the target is within range and inspect the wiring | Realign the sensor, clean the lens or test in a known environment | Readings vary after a controlled retest |
| Drive or lift slips | Look for loose hubs, stretched belts or slipped gears | Tighten hardware, tension the belt and run a slow test cycle | A fastener will not hold or alignment keeps changing |
| Software appears frozen | Check logs, power and the last successful change | Restore the last tested version and rerun a basic test | The failure follows a code change and the cause remains unclear |
This guide is a starting point, not permission to bypass a safety system. A burning smell, damaged insulation, uncontrolled movement or a swollen battery requires isolation and an experienced adult. For deeper faults, photograph the setup, record the symptom and review recent build changes before altering anything else.
Mentors should also look beyond their own club for practical support. Regional STEM organisations, such as the Northwest STEM network, can help teams find experienced mentors, suppliers and ideas that extend the knowledge inside one workshop.
Diagnose one variable at a time
A second failure often begins with the first repair. Before opening a controller or gearbox, establish what changed: a wire was moved, a program was flashed, a fastener was replaced or the robot was hit. Ask the student who last handled it, but verify the answer with a test. This brief history can eliminate half the fault list.
Separate electrical symptoms from mechanical ones. A motor that stays still but draws current may point to a seized gearbox; a motor that moves briefly and stops may point to protection circuitry, a loose phase lead or a low battery. Do not infer from a single observation. Match the symptom to the subsystem and repeat the test with the robot supported off the ground.
Know when to stop testing. Repeated disassembly consumes match time and can erase useful evidence. If the fault is not isolated after two focused checks, call the repair lead, use a known-good component where available and prepare the machine for a legal partial function. A conservative repair that can score may be worth more than a speculative fix that causes another failure.
Adapt to Australian venues and supply chains
Australian competition schedules often connect clubs in Sydney, Melbourne, Brisbane, Adelaide and other regional centres. Long-haul interstate travel can leave teams setting up only hours before an event, so the bench, spare battery and software image must travel as one protected kit. At a Brisbane or Perth event, keep batteries shaded and allow them to cool between cycles; stop using any battery that is swollen, leaking or unusually hot.
Buy and pack for the Australian market: metric hex keys, M3 and M4 hardware and stocked connectors are more useful than an improvised imperial substitute. Suppliers such as Jaycar and ALtronics can help when a local component is needed, although every substitute must match the voltage, current rating and mechanical fit. Australian mains is typically 230V, so check a charger’s input rating; a 110V charger is not safe on 230V.
Price urgent spares in Australian dollars and check whether a quote includes the 10% GST. An overnight international order may attract customs duty, GST and handling fees, so it is rarely the fastest option at an event. Use local stock or a pre-positioned spare instead. Declare overseas purchases correctly and keep the invoice, because border charges and unavailable parts can otherwise turn a cheap component into an expensive delay.
Turn every repair into a team learning loop
Every repair leaves a trace. After the queue reopens, record the symptom, diagnosis, repair, elapsed time and the person who helped. A five-minute debrief can prevent the same failure in the next match, while a short interview with the student who found the fault can reveal an unsafe shortcut. Keep the record factual rather than assigning blame.
Strong partnerships reduce the cost of learning, too. The Maryland business partnerships profile shows how local businesses can contribute equipment, technical expertise and volunteer support. Australian clubs can apply the same principle by building relationships with engineering firms, training providers, universities and community suppliers.
Make repair readiness visible before the next event: nominate a repair lead, pack the triage sheet and spares, and schedule a 15-minute timed drill using a deliberately introduced fault. Invite a mentor, parent, teacher or industry volunteer to run the scenario, then measure both diagnosis time and the quality of the handover. If your club needs help, volunteer as a repair mentor, sponsor a spare-parts kit or join a pit crew, and turn that commitment into a rehearsed team routine.