Mechanical design precision
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Who can tell me about design work? I need to design a product now – how should I approach it, and what are the requirements regarding its processing precision?
It’s Of course easier to explain when there are specific procedures. . .
Based on the functional requirements of the product you are designing, consult the relevant standards; these standards specify what functions must be fulfilled and what level of machining precision is required.
The machining accuracy of a part generally refers to the precision of its geometric dimensions as achieved through mechanical processing, the accuracy of its shape and position, as well as surface roughness, etc. “The term “mechanical design precision” is rare.
It depends on what the key components of the product you are designing are. For example, if it’s a shaft that needs to fit with bearings, then high precision requirements apply regarding the allowable deviation when fitting with those bearings. Of course, for a shaft, its degree of bending is also something that needs to be taken into account. Additionally, you need to consider what kind of fit is required for the components mounted on the shaft; the appropriate fit tolerances are determined based on the working environment. When it comes to interference fits, high requirements are placed on the amount of interference. There are also geometric tolerances, surface roughness, and so on – all of these depend on the working environment, with cost factors also needing to be fully considered.
Depending on the requirements of the designed device, an appropriate precision level for the components is chosen; if the precision is too low, it fails to meet the product specifications, while if it is too high, it becomes uneconomical.
1: The design must meet the functional requirements of the product and comply with relevant standards. 2: Consideration should be given to operational conditions, the manufacturing process routes, and manufacturing technologies; decisions should also be made taking cost factors into account. For example； General machining: A machining technique with a precision of around 0.1 millimeters and a surface roughness of Ra between 0.3–0.8 micrometers; methods such as turning, milling, planing, and grinding are used. Precision machining: A machining technique with a precision of around 10–0.1 micrometers and a surface roughness of Ra between 0.03–0.3 micrometers; methods such as diamond turning, diamond boring, and mirror polishing are employed. This type of machining is suitable for processing key components in precision machine tools and precision measuring instruments, such as precision screws, precision gears, precision turbines, and precision guides. Ultra-precision machining features a precision of 0.1–0.01 microns, with a surface roughness value of Ra between 0.03–0.05 microns. Such machining techniques include diamond tool-based ultra-precision cutting, ultra-precision abrasive machining, ultra-precision special machining, and composite machining. Nanofabrication: A manufacturing technology with a precision greater than 0.001 microns and a surface roughness Ra of less than 0.005 microns; its processing methods are mostly not traditional mechanical techniques but rather methods that operate at the atomic and molecular level.