Electric Motor Terminology

A newcomer to to the hobby often wonders what does terms like double wind or machine wound actually mean. Without knowing these various terms, shopping for a motor can be very intimidating and possibly cause you to waste some of you hard-earned money. So below I'll describe some of the more commonly used terms for describing electric motors.

Modified Motors

Modified motors are motors that have less than 20-turns and what's referred to as stand-up brushes. This means that the brush is taller than it is wide. Usually from the factory these motors already have 10-20° of timing already dialed into them. Although in most cases this is adjustable.

Stock Motors

Stock Motors have 27-turns and a fixed timing of 24°. The timing cannot be adjusted and they use what's called a lay-down brush to transfer the power to the comm. A lay down brush is wider than it is tall. Due to the fixed 24° timing, a stock motor is a poor choice for a backyard bashing motor. Not only will it heat up quickly, but it will not offer the amount of power that a good modified motor will.

The Stinger motor that comes with Traxxas electric RC's is often thought of as a stock motor. However that is only true if you mean the motor that came with the truck. When it comes to the actual RC definition of "stock motors", the Stinger doesn't qualify due to the fact it is a 20-turn motor.

Hand Wound

A hand wound motor is exactly what it sounds like. The windings on the armature have been wound by an actual person, not a machine. This allows for a much neater, and tighter, set of windings. Tighter windings fall back to basic physics lessons. As the windings get closer to the center of the armature, the armature takes less effort to spin. Also tighter windings mean that less wire is used around the armature overall. This leads to less resistance and better efficiency.

A hand wound motor will perform much better than a machine wound motor. In most cases it can also be geared slightly higher as well. The downside to a hand wound motor is their cost, which is usually quite a bit more than a machine wound motor.

Machine Wound

A machine wound motor is one that has had it's armature windings wound by a machine. Production line methods allow for the final cost of the motor to be cheaper, but with less overall power than a hand wound motor.

Turns

Turns is the number of times the wire is wrapped around the armature. Lower-turn motors turn higher RPM's, and can give you a higher top speed. However a lower turn motor will also drain your battery pack faster giving you a shorter runtime.

Winds

Winds refers to the number of wires that are wrapped around each leg of the armature. A lower wind motor, due to inertia properties, is much easier to start turning. Therefore a low wind motor offers more low end torque. A higher wind motor offers more torque at the upper end of the RPM range. This is due to the fact that the extra winding helps keep the motor spinning once the armature is set in motion.