A moulder is a machine used to cut pieces of raw material known as blanks. The cutting is done with cutting heads known as knives, and the knives cut the blanks in such a way that patterns or shapes are created; the machine is not used to cut a piece of wood in half, for example. Sometimes the moulder is also a planer, which is a tool that creates an even surface on a blank, though not all machines are capable of this function. Two general types of moulders exist: single head machines and multi-head machines.
A single head moulder will feature a horizontally oriented shaft on which the knife or cutting head can be mounted. This means one side of the blank is cut at a time, which can be more time-consuming but is ultimately a more accurate process. The blank will be fed into the machine, and the knife will rotate at a high rate of speed on the axle shaft, cutting into the blank as it passes. The knife can be replaced with a different knife of a different shape, thereby allowing the user to create a different pattern on a new blank.
A multi-head moulder will feature more than one rotating cutting heads. A horizontal shaft with a knife is likely to be featured in the machine, though other cutting heads within the machine may be oriented on a vertical plane instead. This means more than one side of the blank can be cut at one time. This is a quicker process, but the machine is likely to be more expensive than a single head moulder, and the cuts may not be as clean and efficient as a single head cut since more vibration may be present during the cutting process.
One of the primary uses for a moulder is the creation of moulding or edging used in the finishing stages of a carpentry project. Toe boards, crown moulding, and other accents within a home can be created with a moulder quickly and easily. Some moulders feature CNC, or computer numeric controls, which means the same cut can be made numerous times on different blanks with little or no difference in tolerances. This is particularly useful when creating many pieces of moulding for a room or for an entire house. CNC machines use computers with special software to control the machine during the cutting process.