Fan blade
1. Manufacturing Concepts
1.1 Product Design Specification of fan blade
To effectively develop a Product Design Specification for the Fan Blade, we need to firstly define the basic functions of the Fan blade. The basic function of a fan is to cause effective air flow in a room and this should be accomplished for a long usage of several years at varying rotations per minute.
The quality of fans is rated by their performance in moving the air effectively and quietly. This is monitored by such factors as the pitch, length, and number of ceiling fan blades, and their revolutions per minute (rpms).The angular edges of the ceiling fan blades are termed as the pitches which are particularly important for the effective movement of the air. The shape enables the blade to apply pressure to the air in front of it and thus the air is forced downwards.
Thus the important specifications required for our component would be: * Effective Air Flow * Low Noise levels * No Wobbling * Durability * Light weight for low power consumption * Should not get rusted. * Aesthetics * Low cost
The higher the pitch the more is the replacement of air. Good quality ceiling fan blades have a pitch of 12-14 degrees. Blade pitches as low as 8 or 10 degrees leads to poorer performance and thus lower Air flow and higher noise levels. While the short ceiling fan blades with minimum pitches can swirl at high speeds, they do not make for much air circulation and they are noisier than the types of fans with longer blades and higher pitch though they rotate more slowly.
One of the issues people sometimes find with their ceiling fans is wobbling. While many people may think that the wobbling is caused by the motor, this is usually not the case. The wobbling of the fan is usually caused by blades that are out of weight alignment. This is due to the use of warped, bent, or unmatched blades. Another reason for wobbling is that the blades may not have been screwed into the brackets straight.
Aesthetics are very important in the design of a ceiling fan as the color and design need to live up to the looks of the place of installment. Different materials like solid wood, cross-laminated veneer and less-expensive veneered constant-density boards are used to render the ceiling fan blades a smart and contemporary look. This also may include a metal finish, or a wooden looks. Contrast or reversible ceiling fan blades are another innovative addition to the whole range of ceiling fan blade designing.
Ceiling fans usually are not replaced for many a years at a stretch. Thus they are expected to be durable to withstand long usage at varying speeds. Though some designs of fan blades may consume low power at the cost of low air flow, a better design would include the use of a low weight material for the fan blade. Rusting of metallic fan blades can cause unevenness in the balancing of the fan blades because of change in weight and it also will affect the durability. Thus the blades need to be coated effectively with paint to prevent oxidation of the fan blades.
1.2 Wooden and Plastic blades in comparison with Aluminum blades
The most widely used materials for making ceiling fan blades are Wood, Plastic and Metal. We have decided on using an aluminum blade for our fan, but let us also consider the other materials too.
Wood had been traditionally used as it is a light weight material that is easily available. It also can be carved elegantly to add beauty to the aesthetics of a home. It is known that the conventional blade of a ceiling fan is made of plywood or solid wood. In the manufacturing procedure, such a blade needs to go through many processing steps such as cutting, planing, multi polishing, finishing, painting and printing or covering with printed paper, etc. Moreover, each blade must finally be weighed and three or four blades of the same weight must be selected as a set for the packing operation. Therefore, the whole