Construction ruleset

This simplified ruleset is for the Plastic Ant (1 lb) weight class at IRL events. The goal is an easy entry point for new builders by limiting materials to commonly available 3D-printable plastics. It is based on the general principles of the SPARC rules — builders attending other competitions should always review the event-specific rules.

1.Weight & locomotion

• Standard weight class: your robot must weigh 1 lb (454 g) or less.
• Weight bonuses for alternative locomotion:
  • Shufflers — up to 1.25 lb
  • Non-traditional — up to 1.5 lb
  • Walkers — up to 2 lb

2.Materials & fasteners

• Chassis, armor, and weapons must be 3D printed from PET, PETG, ABS, PLA, PLA+, or ASA. No other plastics, metals, or composite materials (like carbon-fiber PLA) for these components.
• Non-plastic parts: commercially available motors, electronics, axles, fasteners, and wheels may be any material — but cannot be used to enhance structural integrity, armor the robot, or enhance a weapon. Magnets are not allowed for downforce or traction.
• TPU is banned — with the sole exception of drive/weapon system belts, provided the belt does not enhance structure, armor, or weapon.
• Post-processing is prohibited: no annealing, acetone soaking, strengthening with a soldering iron, or boiling. (Soldering irons may be used to fuse broken parts during pit repairs on competition day, within the spirit of this rule.)
• Fasteners: make reasonable efforts to recess exposed screws, bolts, and metal hardware. Countersunk or recessed fasteners are preferred; large protruding bolts that can be struck during normal engagement are not allowed.

3.Electronics & batteries

• Battery handling: batteries are installed only during match prep or approved testing. After a match or test, remove the battery and store it in a LiPo-safe fireproof bag or container. All batteries (LiPo, Li-ion, LiFe) charge inside such containers.
• Power cap: 3S (11.4 V nominal for 3S HV) for all classes. This is the same “power cap” shown on event class listings.
• Power disconnect: an easy-to-access mechanical disconnect (FingerTech-style switch or removable link) for drive and weapon. Relays are allowed but do not substitute.
• Battery securing: contained inside the chassis, not visible or strikeable from outside.
• Insulation: no exposed terminals or contacts — heat shrink, tape, or enclosed connectors.
• No protrusions: no construction screws may contact or protrude into the battery compartment.
• Power light: a light visible from outside the robot must show when power is active.
• Radio: 2.4 GHz systems only. Toy radios (27 MHz, 49 MHz, Bluetooth) are not permitted.
• Fail-safe: drive and weapon must stop automatically if the transmitter loses power or signal.

4.Safety

• Deactivation: the whole robot (drive + weapon) must fully deactivate in under 60 seconds using the manual disconnect.
• Weapon lock: any moving weapon that could cause damage or injury needs a clearly visible locking device whenever the robot is not in the arena — brightly colored, securely attached.
• Weapon speed: spinning weapons may not exceed 250 mph at the tips.

5.Wheels & padding

• Wheels: off-the-shelf wheels are permitted, including foam and rubber hobby tires and molded plastic wheels (LEGO included). Custom cast wheels are an advanced-class unlock.
• Padding: non-structural padding (foam, rubber, silicone) is allowed, but not as a weapon or armor. TPU may not be used as padding.

6.Prohibited items

• Electrical weapons or RF jamming
• Entangling weapons (nets, strings, etc.)
• Liquids, foams, or gases that require cleanup
• Projectiles, tethered or untethered
• Heat, fire, and explosives
• Pneumatic or hydraulic systems

7.Motors & divisions

• Drive motors: brushed only. This applies to every MS/HS robot — there is no brushless-drive unlock. Brushless weapon motors are permitted.
• Custom cast wheelsremain an advanced allowance: casting only for wheel tread (max 0.25″ thickness) or contact points of non-wheeled locomotion (bristles: max 0.5″ height, spacing ≥ bristle width). Ask before building around it.
• OPEN division: select events offer an OPEN division for all ages that runs standard SPARC rules, not this document — check the event listing.

8.Violations

• Event organizers may disqualify or restrict any robot deemed unsafe, noncompliant, or damaging to the arena. Repeated or deliberate violations can cost match eligibility or XP.
• Spirit of the class: organizers may disqualify a robot that violates the spirit of the class — if you are unsure about a design, ask first.

9.Questions?

For clarifications or pre-approval of borderline components, contact the event host before competition day: info@impactroboticsleague.org.