CNC Roughing vs Finishing: A Comparison Guide
CNC machining is a process that helps manufacture many components for different industries. These components are usually the ones requiring precision and accuracy. Sometimes, the CNC operations alone cannot be enough to give the desired surface finish and dimensions. Hence, the need for roughing and finishing is crucial.
The guide below has an insight into the comparison between CNC roughing vs finishing, so let's read.
What is Roughing in Machining?
Roughing in machining is the process which consists of removing a large amount of material from the workpieces. It is the first stage during processing. CNC roughing helps to produce the shape of the materials, which is close to the required geometry. The roughing process is conducted at a high cut depth, and a large rate of feed, and hence, the chips are eliminated.
Despite ensuring high production efficiency, rough components have a poor finish. The roughing processes do not meet the high dimensional accuracy and required tolerance.
What is Finishing in Machining?
In machining, finishing is the process that layers the surface of the manufactured components. This involves enhancing the aesthetics of the component. The finishing process includes granallado, polishing, recubrimiento en polvo, electroplating, and grinding. Finishing enhances the smoothness, adhesion, corrosion resistance, and hardness of the components.
Benefits Of Roughing
The process of roughing has various benefits, and some of these are as follows:
- The process of roughing removes materials at a very fast rate. It improves the efficiency of the process of enhancing the component.
- Roughness protects the finishing tools from wear and tear. A significant chunk of material is removed from the material through roughing. It ensures that the finishing tools are not subjected to much stress.
- Roughing sets the base for the finishing. It shapes the workpiece and makes it precise to a greater extent. Hence, the component is prepared by roughness, which later on can be finished.
- Roughing tends to reduce the time required by the subsequent process of machining. Hence, the time and cost of manufacturing are reduced.
- Machinists can make deeper cuts in the components, which are not possible in the finishing process.
Benefits Of Finishing
The finishing process also has various benefits, and these are as follows:
- Finishing offers high dimensional accuracy, and the required tolerance is achieved.
- The finishing process enhances the smoothness of the components and makes them appear polished and aesthetically appealing.
- Finishing improves the durability of the component by adding a layer of treatment, which makes the component resistant to wear and corrosion.
- The finishing process enhances the rough surface by reducing the friction in the components.
- Finishing improves the lifespan of the components; it enhances the quality of the surface and reduces the need for replacements.
Differences Between CNC Roughing vs Finishing
The section below highlights in detail the comparison of roughing vs finishing.
Propósito
Roughing:
Roughing quickly removes a maximum amount of material from the component. It is less precise and very quickly converts the block of material into the required shape.
Finishing:
Finishing refines the component. It ensures that the component matches the design specifications and that the precise dimensions are achieved with the desired finish.
Rate of Material Removal
Roughing:
Roughing removes the material at a very fast speed and creates wide and deep cuts by removing material.
Finishing:
Finishing has a slow rate of material removal, and it creates precise and light cuts which do not reduce the component but rather refine it.
Feed Rate and Cutting Depth
Roughing:
Roughing involves using a high rate of feed and creates deep cuts with quick removal of materials.
Finishing:
Finishing uses a very slow feed rate with a shallow crust and maintains a high-quality surface with precision.
Acabado superficial
Roughing:
Roughing creates a rough surface, finishing the material is removed abrasively from the workpiece.
Finishing:
Finishing creates a smooth and polished surface of the component, enhancing its aesthetic appeal.
Dimensional Accuracy and Tolerance
Roughing:
Roughing does not consider dimensional accuracy and exact tolerance; it just brings the shape of the workpiece close to the final component.
Finishing:
Finishing ensures meeting exact tolerance in the designs and ensures that the parts fit and work as expected.
Herramientas de corte
Roughing:
Roughing uses cutting tools that are large and can withstand abrasive and heavy cuts.
Finishing:
Finishing uses fine and small-sized tools, creating light cuts and enhancing the surface smoothly.
Coolant Use
Roughing:
The roughing process produces more heat, and hence, it requires more coolant for heat dissipation to prevent the workpiece from damage.
Finishing:
In the finishing process, the need for coolant is less than roughing due to slow feed rates.
Timing
Roughing:
The roughing process comes first, the component has to pass through the process of roughing before finishing.
Finishing:
Finishing comes after roughing once the component has been shaped and needs final touches.
Considerations for Rough Machining
The considerations that play a vital role in ensuring seamless roughing in the machining process are discussed below.
Machining Parameters
CNC roughing tools have pre-selected parameters for cutting, depth, and feed rate. However, these parameters cannot predict the specific roughing operation considerations. Hence, the roughing parameter must be optimized and selected according to the nature of the component and its applications.
Tipo de material
The type of material machined also impacts the roughing process. Materials that are complex need a slow feed rate and speed that prevents tool damage, whereas the softer ones can handle aggressive cuts.
Tool Selection
Choosing the right type of cutting tool is very important. A tool which is huge and has a sharp cutting edge is suitable for roughing as it can withstand abrasive cutting.
Work Holding
The workpiece needs to be held securely. Hence, the work holding is an essential aspect of roughing. It helps to keep the workpiece intact with the aggressive cutting force applied.
Heat and Cutting Fluid
During the roughing process, the need for dissipation of heat is very important. The use of coolant ensures that the heat is dissipated and tool wear is prevented.
Considerations For Finish Machining
The important considerations for finishing in machining are as follows:
Dimensional Accuracy
Dimensional accuracy is the core consideration in finishing. The components, when subjected to finishing processes like powder coating, the surface thickness increases and hence, the dimensional accuracy must be matched.
The Application of Workpiece
The application of the component and the condition will be subjected to needs analysis when selecting the finishing process. For instance, if the automobile needs components that are not at the front, they need to be more focused on durability, so finishing is not something that the emphasis will be on.
Post-Processing
Post-processing involves the surface treatments that the components may need after machining. It may include heat treatments as well as other processes.
Hence, the post-processing during the finishing process will impact the dimensions of the part, its mechanical properties and even resistance. It is important to plan everything before finishing, including the post-processing required.
Coste
The overall cost of the project requires an analysis based on your budget. You can choose the finishing of the component as every finishing process differs in terms of materials and processes, and needs a cost analysis.
DEK’s One-Stop CNC Machining Shop
DEK is a one-stop service provider for your components, whether you need roughing of the components or finishing. We also offer to provide you with components finalized completely in terms of shaping and finishing.
So, get in touch with us today, and we will design and manufacture your final components with high quality and precision.
Conclusión
When machining components, the need to understand the difference between roughing and finishing is very important. It helps in making the right selection of processes, analyzing the product parameters, and achieving what you expect.
