ELECTRIC HAIR CLIPPERS

This is a powerful motor for hair clippers.  Check it out.  "Single cut vibrator clipper. Powerful v5000 motor.  Balding (6 x 0) blade adjusts to zero-overlap. Powerful single cut clipper with surgical blades for full head balding."  And it can be found on Amazon for $39.60.  A bit pricey for my blood.  You can get less powerful clippers for a smaller price, but if you're looking for a powerful motor that won't die down when cutting through longer hair, these shears seem to be the ones to buy.

  

Motor Type
Hair trimmers all operate using one of three motor types that affect performance and power. Rotary motors provide the most power and speed, though with the downside of being bulkier. Magnetic motors generate more speed with moving the blades, but lack the force needed to cut through thick or wet hair. Pivot motors move the blades much more slowly than other motors, but have the power needed to cut through thick and wet hair.

Rotary Blade

The David Warren Channel

Warren recommends the Andis Super Liner above.  The price is $50 at Amazon. But the descriptions do not reassure me.  I am looking for something powerful enough to cut through thick tufts of dry hair.  The descriptions at Amazon suggest that this is more of a trimming clipper that works best on the edges in shaping the outline of a cut and not the best clipper for macro cuts across and over the scalp.  Here is Amazon's description:

Powerful but quiet rotary motor trimmer with ergonomic design

Detachable blades for easy changing and cleaning

Equipped with Andis' close-cutting stainless steel t-blade

Designed for outlining, detailing, shaving and shaping of hair

Maintenance free motor, no grease or oil needed.

Some men's hair cutting terms--here and here--that should not be avoided if you want to know what you're buying or if you want to communicate effectively with your barber.