SPARC Robot Construction Specifications

The SPARC Robot Construction Specifications are the safety and build rules a robot has to meet to pass inspection at a SPARC-rules event. It is one of the SPARC documents, and the one builders will refer to most.

Current version: SPARC Robot Construction Specifications v1.7

This summary is based on v1.7 (1 September 2026). It is an overview only – always check the current document and your event's own rules. Events often change parts of this document, and must say which parts they changed.

General and safety rules

• Everyone builds and competes at their own risk. If a design is unusual or might be borderline, contact the event before you arrive.
• Every robot must pass the event's safety inspection, and builders must tell inspectors how everything works and what the dangers are. Spare robots are allowed if they are identical and also pass inspection.
• Cardinal safety rules include:
  • Only activate a robot in the arena, an official test area, or with the event's permission.
  • Every robot must be fully deactivated (drive and weapons) within 60 seconds using a manual disconnect.
  • Outside the arena, robots must be blocked up so the wheels or legs can't move it.
  • Dangerous weapons need a clearly visible locking device whenever they're out of the arena, and it must stay in place while the robot is powered on.
  • Radios that aren't spread spectrum can't be switched on at an event without permission.

Weight bonuses

The weight classes come from the event (see Tournament Procedures for the SPARC class names). Robots that don't roll get extra weight:

Locomotion	Bonus	Example: 3 lb class	Example: 30 lb class
Rolling (wheels, tracks)	none	3 lb	30 lb
Shuffler (rotating cam-operated legs)	1.25×	3.75 lb	37.5 lb
Non-traditional (bristle/vibration drive, gyro walkers, hovercraft)	1.5×	4.5 lb	45 lb
Walker (no rolling or cam-driven parts touching the floor)	2×	6 lb	60 lb

Jumping, hopping and flying robots may be allowed at some events. Talk to the event early if you're entering anything that doesn't roll, so you know which bonus you'll get.

Control and electronics

• Robots must use digitally coded 900 MHz or 2.4 GHz radios (or a control system the event has approved).
• Losing signal or transmitter power must stop all drive and weapon motion.
• You need at least two available frequencies or channels; frequency-hopping radios meet this.
• Autonomous robots must be cleared with the event before registering, need a visible indicator light for each autonomous system, and must be armed and disarmed remotely.
• Batteries must not be able to spill when damaged or upside down (wet-cell lead-acid batteries are out). Voltages above 48 V nominal need approval.
• There must be a mechanical main power disconnect that can be reached within 15 seconds without risk, and a visible light showing that main power is on.

Pneumatics and hydraulics

• Pneumatics must use non-flammable gases such as CO₂, nitrogen or air. Robots of 12 lb and under, or with 2 fl oz of gas storage or less, are exempt from most of the pneumatic rules if they stay at or below 250 psi.
• Larger systems need components rated for their pressure, tanks rated to 120% of working pressure with a current hydro-test, burst discs, a main shut-off valve and a bleed valve that stays open outside the arena.
• Hydraulics follow similar rules. Robots of 12 lb and under are exempt from most of them but are limited to 250 psi.

Weapons

• Spinning weapons must stop within 60 seconds of losing power, using their own brake. Spinners that can hit the outer arena walls need approval.
• Springs and flywheels may only be loaded or spun up inside the arena, and must fail safe.
• Forbidden: electrical weapons, radio jamming, magnets that affect other robots' electronics, entangling weapons or defenses (nets, string, tape), liquids, foams, powders and other messy weapons, untethered projectiles, and lights or smoke that block anyone's view.
• Off by default (events can allow them with extra rules): internal combustion engines, fire, smoke effects, and tethered projectiles (on a tether of 8 ft or less).

See also

• Robot Classes
• SPARC Restricted Class Regulations – extra limits for Sportsman and Plastic classes
• Batteries, Radios, Switches, Weapons