Hobbyweight

The Hobbyweight class is for robots weighing up to 12 lb (5.44 kg). It's the step between the insect classes and the bigger robots: big enough for serious engineering, but still manageable to build, transport and repair. It's fought mainly at NHRL and some larger events.

Rules

• SPARC: 12 lb (5.44 kg), called Hobbyweight in the SPARC Tournament Procedures. Shufflers can weigh 15 lb, non-traditional drives 18 lb, and walkers 24 lb. Robots of 12 lb and under are exempt from many of SPARC's pneumatic and hydraulic rules if they stay at or below 250 psi (see SPARC Robot Construction Specifications).
• NHRL: 12 lb, under NHRL's own rules.
• There's no equivalent FRA class in the UK. Some events run a 12 lb Sportsman class. The National Robotics League uses a related 15 lb class for high schools.

Typical builds

• Drive: brushless motors through planetary gearboxes, such as Repeat Robotics' 12 lb gearboxes for 28 mm and 35–36 mm motors.[1]
• Weapon: larger brushless motors (often from RC cars or electric skateboards) with high-current ESCs.
• Battery: commonly 4S–6S LiPo.
• Materials: mostly aluminum or machined plastic frames, with steel and titanium armor and weapons, and printed internal parts.[2]
• Arena: 12 lb robots need an arena built for robots up to 30 lb – SPARC recommends 3/4" polycarbonate walls for that range.

Getting started

There aren't many complete 12 lb kits; most builders design their own robot and buy drive and weapon parts. NHRL's starter guide says a fairly competitive 12 lb robot can be built for under $1,000.[3] Building a beetleweight first is a good way to learn.

Where they fight

Mainly at NHRL, and at some larger events such as Robobrawl at the University of Illinois.

NHRL 12 lb world champions

Year	Champion
2021	Hot Leaf Juice
2022	Ugee
2023	Full Court
2024	SLAM PLAN
2025	Pramheda

Source: Wikipedia and the NHRL event winners list.

See also

• Beetleweight (3 lb) and Featherweight (30 lb)
• Robot Classes