Please note that these are specifications for 550 motors that are only legal in the 4X4 Short Course Category.
8.8.6 10th scale 4×4 Short Course Truck (SCT) 550 Motor
Maximum overall length is 73.0mm measured from the mounting face of the motor to the furthest most point on the endbell, not including solder tabs, lead wires,sensor plug or housing, or the manufacture’s logo or name. Motor mounting holes must be on 1.00 inch (25.40mm) centers. Diameter is 36.0mm
Motor stator minimum length is 35mm (+/- 0.15mm) with maximum length of 42mm and the outside diameter is 36mm. The thickness of the laminations shall be 0.35mm. A ‘go-no-go’ gauge 14.500 +0.000/-0.005mm diameter shall pass into the stator, clearing the stator plus its windings and the electrical collection ring at the end of the stator.
External shaft diameter may be either 0.125 inches (3.175mm) or 0.197 inches (5mm). Only one piece, two pole Neodymium sintered, or Ferrite (Ceramic) magnetic rotors are permitted. The magnet length shall be a minimum of 39.0mm and maximum of 46.0mm not including any nonmagnetic balancing material. The magnet outside diameter shall have a minimum of 12.3mm and a maximum of 14.0mm, no tolerance, for the entire length of the magnet.
***Please refer to the class rules, which indicated that these systems in 4X4 Short Course trucks are limited to 7.4v lipo batteries ONLY. The batteries need to comply with ROAR rules regarding the use of “hard case” packs already approved for use in ROAR competition. Use of any non-approved batteries or higher voltage 3S or 4S packs is strictly prohibited. There will be no exceptions.