Lathe
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The basic lathe
There are many forms of wood lathe. The simple lathe shown in the picture here is representative of the majority of lathes used in contemporary woodturning. The headstock is where power is applied to rotate the wood, which is fastened to it, in this case using a faceplate, but several other fixings are available. The bed (or 'ways') permit the toolrest and tailstock to be held in a place relative to the headstock. The toolrest is a bar of metal upon which the operator supports the gouges and chisels while they are cutting the wood; it is held in place by the banjo. The tailstock slides along the bed and can be used to provide support for long pieces of wood. The lathe is supported by a stand, or it may be mounted on a bench. Most lathes today are powered by electric motors.
There are many variations on this basic form of lathe:
- Bowl lathe comprises headstock and toolrest. There may be no fixed bed at all, the toolrest supported on a separate stand or some other mechanism mounted to the lathe.
- Ornamental lathes have fixed or rotating cutters, and functions more like a metal lathe or mill.
- Pole lathes are powered by foot by way of a cord attached to a long springy pole. The wood alternately rotates forwards and backwards as the pole goes up and down.
- Treadle lathes are also powered by foot, but the up-down movement is converted to continuous forward rotation.
The parts of a basic modern lathe
Headstock
The headstock spindle is supported by two or more bearings, and is usually driven by an electric motor via pulleys and a belt. The spindle is usually threaded for the attachment of faceplates and chucks, and most spindles have a morse taper to accept spur drives or drill chucks. An axial hole through the center of the spindle allows morse tapers to be knocked out, and allow the use of vacuum chucks. The spindle can often be locked in position, and an index plate may allow it to be locked in one of many fixed positions.
There are numerous ways to transfer power from the motor to the spindle. Most common is perhaps the use of multi-step pulleys, enabling a small number of fixed speeds to be selected by stopping the lathe and switching the belt from one step to another. The Reeves drive is an alternative method which allows continuously variable speed by way of two variable-diameter pulleys.
The use of electronics to drive either a 3-phase or a d.c. motor is an increasingly popular and affordable way to achieve continuously variable speed control. Some lathes have gone as far as building the motor around the headstock spindle, thus doing away with the need for belt drives altogether.
On some lathes the headstock is capable of rotating. This is mainly used in faceplate turning, and it allows the turner better and more comfortable access to the face of the workpiece.
Tailstock
The tailstock is mainly used to support the workpiece at the opposite end to the headstock. This is essential when turning spindles driven by a spur centre, but is sometimes used in faceplate turning to provide extra support of heavy or out of balance workpieces.
The tailstock slides along the bed and is locked in place by a lever. The tailstock quill is a spindle which is aligned on the same axis as the headstock spindle. It can be moved in and out along this axis by a hand wheel. Like the headstock spindle it usually has a through hole along the axis and a morse taper to accept accessories like a live centre to support the workpiece, or a Jacobs chuck to permit drilling operations. The quill can be locked by a lever or knob.
Banjo and toolrest
The banjo slides on the bed and is locked in place by a lever. The toolrest shaft can be raised, lowered and rotated. It is locked in place by a lever.
Stand
The stand may be either an integral part of the lathe, bolt-on legs, or a shop built bench.
Choosing a lathe
There are many factors to consider when planning a lathe purchase:
- Budget
- Lathes range from a few hundred US$ to several thousand.
- Type of woodturning you want to do
- What exactly do you want to make. Will this be occasional hobbyist use or full time professional work?
- Scale of work you want to make
- Do you plan to make small items, or large pieces from unbalanced green wood?
When looking at a particular lathe, consider:
- Ease of use
- How easy is it to adjust all the moving parts?
- Robustness
- Is it sturdy enough for the type of work?
- Accuracy
- How well aligned are the headstock and tailstock? Is the tailstock quill a good fit?
- Reputation
- What sort of reputation does this machine have in the woodturning community? How good is the manufacturers warranty, support and spares availability?
Lathe manufacturers
- Delta
- Jet
- Oneway
- Powermatic
- Rikon
- Teknatool International
- Turncrafter
