Hobbyweight

From Combat Robot

The hobbyweight weight class limits entrants to a weight of 12 lbs.

Contents 1 Common Components 1.1 Drivetrain 1.2 Weapons 1.3 Speed Controllers 1.4 Component Links

Common Components

Drivetrain

Most motors used for drive in the 12lb class are of the Mabuchi RS-550 size or smaller. A very common drive solution uses the motor and planetary gearbox combination found in low-cost cordless drills. A few other robot-specific gearboxes have been developed for this weight class, such as those sold by Team Whyachi and BaneBots.

Weapons

For the most part, any weapon that can be used in other classes can be adapted to a Hobbyweight. There are several common types of weapon motors used.

• Small to medium size airplane brushless motors. The most competitive Hobbyweight robots often use these motors. An example is Alos which used a Lehner brushless motor to good effect.
• Rare-earth magnet brush motors comprise the second best power-to-weight ratio, and thus are popular in Hobbyweights. The sizes used in Hobbyweights and similar classes are usually built for high performance R/C airplanes and boats. The AstroFlight Cobalt-40 is a popular motor in this category. Due to the prevalence of samarium-cobalt magnets, these motors are often referred to as simply "cobalts".
• Standard ferrite motors are the most common and generally least expensive, but also the least power-dense. The inexpensive Mini EV is a popular motor in this category, as are cordless drill motors, R/C hobby motors, and small industrial motors.

Speed Controllers

A compact yet high-power speed controller is desirable in a Hobbyweight. For this reason, some builders have used controllers developed for "hobby" cars, boats, and airplanes. Others opt to run robot-specific controllers such as the Victor 883 for higher current handling and reliability. There are also numerous controllers that were designed especially for use in Hobbyweight and similar-sized bots from companies such as Banebots and Robot Power.

Component Links

• BaneBots gearmotors: The 28mm and 36mm ones are promising for this size.
• Harbor Freight 14.4V Cordless Drill: A low-cost drill with a useable motor and gearbox combination.
• BaneBots ESC
• Robot Power Scorpion XL: Another suitable ESC
• Astroflight, Inc.: Cobalt and brushless motors.