Safety

Robot combat is built around controlled destruction, and even small robots carry a lot of energy in their weapons and batteries. Almost every rule at an event exists to keep people safe, and safe habits in your workshop and in the pits matter just as much as what happens inside the arena. This page is a starting point: it gives a short overview and points to the pages and outside guides that cover each topic in detail.

The SPARC rules set out the standard safety requirements used by most US events – read them rather than relying on summaries, and always check your event's own rules too.

The basics

These are the habits every builder needs, whatever the weight class:

• Never power on a robot outside the arena or a test box unless the event's safety staff say it's OK. Runaway robots and spinning weapons in the pits are a serious danger.
• Use a weapon lock whenever the robot is out of the arena. It must be clearly visible (bright colors or a "remove before fight" tag), physically stop the weapon, and stay in place while the robot is being switched on. It comes off last when powering up and goes back on first when powering down.[1][2]
• Block your robot up in the pits so its wheels can't touch the table.
• Make sure you can switch it off fast. SPARC requires a mechanical disconnect you can reach within 15 seconds without putting yourself in danger, full shutdown within 60 seconds, and a light that shows when the robot is on (see Switches).
• Make sure it stops on its own. If the radio signal is lost or the transmitter is switched off, all drive and weapon motion must stop. SPARC v1.7 requires this failsafe on every robot (see Failsafes).
• Follow the power-on and power-off order in the SPARC Match Rules: point the robot and its weapon away from people and doors, transmitter on before robot power, and weapon lock removed last.
• Protect your eyes when testing, and keep people out of line with a spinning weapon.

Topics

Topic	Where to read more
Batteries – charging, storage, damaged packs and fires	LiPo Battery Safety, Batteries
Radio failsafes – making sure the robot stops when signal is lost	Failsafes, Radios
Power switches and removable links	Switches
Testing spinning weapons safely	Test Boxes, Spinner Design
Construction safety rules (pneumatics, hydraulics, forbidden weapons)	SPARC Robot Construction Specifications
Arena safety, door locks and fire equipment for events	SPARC Arena Construction Best Practices
What to do at an event	SPARC Match Rules, Events

At events

• Expect a safety inspection before you compete. Inspectors typically check your weight, power switch and power light, weapon lock and failsafe. Be ready to explain how everything on your robot works, as SPARC requires builders to disclose all operating principles and dangers.
• Only test robots where the event allows it, usually in a test box or the arena. Some events, such as NHRL, require all drive and weapon testing to be done in a test box.[3]
• Bring robots to the arena switched off, with weapon locks in, and don't activate anything until the arena door is closed.
• Never leave a battery charging unattended. Many events penalize it.
• Know where the event's fire equipment and LiPo containment are. If a robot catches fire, the standard response is to contain it and get it outdoors (see LiPo Battery Safety).

Outside guides

• SPARC – the standard US rules, including the Robot Construction Specifications (with the Cardinal Safety Rules), the Match Rules and the Arena Construction Best Practices
• NHRL Rules and NHRL Weapon Lock guide – detailed safety rules from the National Havoc Robot League, including what makes an acceptable weapon lock
• Fighting Robot Association – Rules and Safety – the UK build rules and technical checks
• Servo Magazine – Safe(r) Beetleweight Testing – building a test box
• Team Run Amok – Radio system functions – failsafe settings explained for combat robots
• RioBotz Combot Tutorial – a free, very thorough guide to designing and building combat robots