One of the fundamental differences between plastic gears and metal gears is the difference in manufacturing methods. Almost all metal gears are cut, ground and machined, and molded plastic gears are made from molds. The use of wire cutting, can make the spur gear cavity to achieve the accuracy of 2.5μm, but because the method has not developed into processing, any position of the cutting error may occur, must be the entire internal gear cavity detection, processing metal gear only need to detect several representative The teeth. On the other hand, since the shrinkage of each part of the molded plastic gear is different and any mold position may be abnormal, it is necessary to detect the gear member. The advantage of molded plastic gears is that any particular gear can be molded as long as it can be drawn in CAD. What is the challenge is how to measure and adjust the shrinkage and molding of molded plastic gears. With regard to the application of full tooth profile detection technology and the advantages associated with the development method, metal gears can also benefit from molded plastic gears.

Plastic gears and metal gears vary depending on the processing method. Metal gears are cut or ground, is a rotary machining, with high concentricity, diameter accuracy is also easier to ensure that the manufacturing does not consider shrinkage compensation. Plastic gears are molded and coaxial is more difficult to assure, but contours are more accurate than metal gears because the gear cavity accuracy of the wire cutting process is higher than the accuracy of the gear cavity machined with roller electrodes.

Plastic gears are less powerful than metal gears, but with the lack of self-lubricating, light weight, low noise, the advantages of metal gears. In the case of molded gears, large, continuous and repeatable shrinkage characteristics of the engineering plastics in the mold cavity should be taken into account. Under normal circumstances, the plastic gear diameter tolerance than metal gear.

Plastic gear tolerances and gear ratios are recommended based on the structure of metal gears, but these plastic gear standards are unreasonable because it can not accurately predict the plastic gear's function and life even if the resin material is distributed Plastic properties are provided when the plastic gear enters or leaves at high speed When engaged, the manufacturer can not accurately determine the true parameters of the material. The characteristics of traditional plastics have long been proven.