The Technique of FURNITURE MAKING
Transfer units
Robot arms, commonly used for welding work in the car industry, have some applications in the furniture industry. More properly called transfer units, they may be used for moving work between machines, or in a modified form for furniture polishing work. In this application the arm is used to grip a spraygun and apply lacquer to the prepared furniture or components. The flow rate of lacquer to the gun is controlled by further automatic machinery. For these applications, the transfer unit may be programmed using the CNC system, or more simply 'led by the nose' through its appointed task. The unit is put into learn' mode and then an experienced craftsman sprays a sample chair with lacquer, using the gun fixed to the robot
arm. As he sprays the sample each tiny movement and each change in flow rate of lacquer is stored by the machine memory bank. The robot arm is now capable of repeating the task under power as often as required to spray a whole batch of identical items. The learning process has to be repeated for each new style of chair produced. One of the benefits of this method of finishing is that health hazards are reduced, since the machines can work away from occupied areas of the plant, and tolerate high levels of air pollution without harm.
Small workshop automation
The area where CNC machines have had most impact on small workshops is in the making of upholstery and soft furnishings. CNC sewing machines are less expensive than most automatic machines and are used to speed up tasks like quilting, seam binding, and edging.
At the moment large computerized woodworking machines are too expensive to buy and programme for small workshops producing a wide range of items in relatively small amounts. For some time they will be used in bigger companies which can cover their cost. One of the ways in which the real benefits of new technology can help small workshops and individual craftsmen is by grouping small firms around a central facility equipped with automated machines of all types, capable of turning out components to very high standards. The user-group will share the costs of a central CNC facility and use its output as required. CNC machines of this kind can be used to make standard items to help small makers meet their overheads, and allow them to spend more time creating the individual items which their customers require.
A similar method of group machining was first used when power machinery was introduced and it enabled many small works to survive until machines became generally affordable. Groups of this kind are being discussed now and may be in operation by the early 1990s. Failure to use some of the advantages of economy and accuracy that robot machines bring may possibly cause contraction of the furniture industry into a small number of very large concerns, and a handful of individual designer craftsmen who survive by providing an individual service.
