Mother's Wood Lathe Survey

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If you're in the market for a heavy-duty machine, look for a substantial cast-iron headstock frame; if it's the type that swivels or moves for outboard turning, be certain it locks solidly to the bed in both positions. Also, check out the spindle shaft and bearings . . . a 12" lathe should have at least a 1 "-diameter axle and sealed ball or roller bearings to survive substantial rotational and radial loads.

Only to a slightly lesser extent is the durability of the tailstock important. Though it contains considerably fewer moving parts, it too must fasten firmly to the bed and maintain a straight line to the driven center, regardless of where it's positioned on the ways. Consider, as well, the stroke of the tailstock spindle. That shaft should have a travel of at least 2", not only to allow you to secure the work properly, but to facilitate the use of a chuck and drill bit. The spindle should also lock securely in any position.

And just as critical as the headstock and tailstock is the bed upon which they rest. Though some of the tube rail and box beam designs are quite substantial, quality cast iron has the advantage of sheer mass . . . which absorbs shock and vibration, boosts rigidity, and is built for the ages.

The question of how much power you need can only be answered when you know the size of the work to be turned. Quite naturally, the larger the diameter and mass of the stock, the greater the need for horsepower. In general, the lighter-duty machines can get by comfortably with a motor built to deliver 1/2 continuous horsepower. With a heavier machine, a 3/4-horsepower unit is common, though 1-horsepower and greater motors are often fitted too. (It's important to be sure that the figures quoted are for continuous, or rated, horsepower; peak, or developed, ratings don't reflect the motor's long-term usage capability.)

Speed control is also related to power requirements. When you're roughing large-diameter pieces, you may need turning speeds as low as 200 or 300 RPM, but you'll also need torque at the spindle. A conventional stepped-pulley design is fine, because it offers simplicity as well as the necessary "low gear" ratio. For added convenience, manufacturers have developed a mechanically controlled, continuously variable belt drive system that allows speed changes in motion while still maintaining torque . . . but some smaller machines use variable voltage controls to govern speed, which reduce motor power when it's needed most and thus sacrifice function for ease of operation.

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