Lathe
A lathe is a machine to rotate workpieces to perform various operations such as sanding, knurling, drilling, deformation, etc.
Woodworking lathes
Woodworking lathes are the oldest variety. All other varieties are descended from these simple lathes. An adjustable horizontal metal rail – the tool rest – between the material and the operator accommodates the positioning of shaping tools.
What are the parts of a wood lathe?
The parts of a wood lathe include the stand it rests on, the power switch, the headstock, the speed control, the tool rest, the tailstock and the motor.
How to Use a Wood Lathe
1. Select a lathe suitable for your project
Benchtop lathes can be ideal for turning small projects like ink pens and yo-yos, larger machines may be used for making spindles used in furniture and handrail styles. Here are some differences in wood lathe specifications:
- Bed length is the distance between centers or the maximum length of the stock that can be turned.
- Swing is the term used to describe the largest diameter stock that can be turned.
- Horsepower is the amount of torque the lathe motor develops, which in turn will determine how heavy an item can be turned without overloading this critical component.
- RPMs are the revolutions per minute the stock can be turned. Here, note that most, if not all lathes have variable speed capabilities. A lathe with a very low-speed range allows the user to start a piece of odd-shaped, unbalanced stock without excessive vibration, and high-speed machines can speed the work while making obtaining a fine, smooth finish easier to achieve.
- Weight and composition. Heavier machines with cast iron beds and steel frames offer a good, solid work platform, but can be difficult to move if you are operating it in a crowded workshop where you will be storing it when it is not in use.
2. Choose the lathe operation you are going to begin with.
A simple task might be to turn a square or irregularly shaped piece of wood into a true cylindrical shape, often the first step to forming a spindle or other round item.
3. Select the correct cutting tools for your objective.
Lathe tools are called chisels. They feature long, round, curved handles to afford a solid grip and sufficient leverage to enable the turner to control the cutting edge accurately with minimal fatigue. Common wood chisels simply are too short and are ill-designed for this purpose. Here are a few of the many types of turning tools you may find:
- These usually have specially shaped cutting edges for performing particular cuts, such as bowl gouges, with concave, curved cutting edges to form the smooth, curved surface of a bowl, or vee, or knurling gouges for cutting grooves or knurls in wooden spindles.
- These are often flat or slightly curved chisels for removing wood from flat or cylindrical shapes, or for roughing out a shape.
- Parting tools. These are thin, vee-tipped tools for cutting off workpieces.
- Spoon cutters have a spoon-shaped cutting edge and are also often used for shaping bowls.
- Other tools you may encounter are skew chisels, fluted gouges, spindle gouges, and nose chisels.
4. Learn the components of your lathe.
A basic wood lathe consists of a bed, headstock, tailstock, and tool rest. Here are the functions of each of these parts.
- The headstock consists of the drive train, including the motor, pulleys, belts, and spindle, and for a right-handed turner, will be located on the left end of the lathe. Mounted on the end of the headstock facing the tailstock is the spindle and the spur center or for face turning such as bowls and plates, or other flator face work, the faceplate assembly.
- The tailstock is the free spinning end of the lathe and has the tailstock spindle and the cup center, as well as a hand-wheel or other feature for clamping or securing the workpiece between the lathe centers.
- The tool rest is similar to a mechanical arm with a metal guide bar to support the chisel used for turning the workpiece. It usually can be adjusted by sliding the length of the bed at its base, with an intermediate arm that can swing from a parallel to a perpendicular position in relation to the lathe bed, and the upper arm, which holds the actual tool rest bar. This assembly has as many as three swivel joints, all of which tighten with a setscrew or clamp to keep it secure while turning is in progress.
5. Read your owner's manual before proceeding with actual lathe work for specific instructions, features, and detailed safety instructions.
- Keep your owner's manual handy for reference if you decide to purchase accessories for your particular lathe, for maintenance instructions, and for reference to capacities and specifications for your machine.
6. Select a suitable piece of wood for your project.
- For a beginner, using softwood like southern yellow pine, lodge-pole pine, or balsam fir may be a good idea. Look for a piece with fairly straight grain, and few, tight, knots. Never turn a split piece of stock, or one with loose knots, these may separate during turning, and become projectiles traveling at a significant speed.
7. Square the stock.
- For example, if you are going, to begin with, a piece of 2X4 lumber, rip it to a nominally square shape, such as 2X2. You can then chamfer, or bevel the square corners, effectively creating an octagonal piece, which will reduce the amount of wood that must be removed to reach your desired cylindrical shape.
8. Cut the stock to the desired length.
- For a beginner, starting with a relatively short length, less than 2 foot (0.6 m) long for an intermediate, or medium-sized lathe, is a good choice. Longer workpieces are difficult to true, and maintaining a uniform diameter along the length of a longer piece can take a lot of work.
9. Mark the center of each end of your stock, and position it between the lathe centers.
- Assuming the tailstock is not locked in position, slide this until it pushes the cup center into the tail end of your workpiece. Using the hand crank, tighten the tailstock spindle so that it pushes the stock into the spur center, mounted on the headstock spindle. Make sure the workpiece is securely held, and all clamps are tightened, otherwise, the workpiece may fly off the lathe while you are turning. Also make sure the lathe keys are out of the machine before you start.
10. Position the tool rest parallel to the length of the workpiece, keeping it far enough back to allow the workpiece to rotate without hitting it, but as close as possible.
- A good working distance is about 3/4 of an inch. Remember, the closer the tool rest is to the turning workpiece, the more leverage and better control you will have with your knife (chisel).
11. Free spin, or hand turn the workpiece to make sure it doesn't hit the tool rest.
- It is a good practice to always turn a workpiece by hand before turning the lathe on, making sure it has sufficient clearance.
12. Choose the chisel you will use for the turning operation.
- A roughing gouge is a good choice for beginning to turn an irregular or square workpiece down to a round shape. Practice holding the tool on the tool rest, using your left (again, for right-handed persons) hand on the metal blade behind the tool rest, and your right near the end of the handle. Keeping your elbows in, and braced against your body will give you better control of the tool.
