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The industrial manufacturing sector has witnessed a massive rise in competitiveness owing to ever-advancing technological leaps. Apart from the developments, challenges involved in manufacturing high-quality components at minimum expenses have also surfaced.
To minimize manufacturing obstructions, the CNC grinding system has entered the picture and revolutionized the grinding industry as we know it.
A Complete Guide to CNC Grinding
CNC grinding machines employ a rotating grinding wheel designed to remove material from a workpiece via cutting. Machinists employ CNC grinding to perform hard-fine machining of various components.
To provide you with deeper insights into CNC grinding, here is a detailed guide on the same –
What is a CNC Grinding Machine?
A CNC grinding machine is a precision performance tool that helps remove material from a metal workpiece by a rotating wheel and cutting process. Machinists use CNC grinding machines when they reach the finishing stage as it helps render a superior-quality and smooth finish to the metal workpiece.
The rotating wheel rotates in a fixed position, while the workpiece attached to the machine table moves in all three axes, namely X-, Y-, and Z. The workpiece movement depends on the component’s size, which leads to the grinding wheel taking several passes to deliver desirable dimensions.
A high-quality finish in metal pieces is desirable in ball bearings, camshafts, transmission shafts, and other working pieces that demand precision and minimum scope for error. While a CNC grinding machine primarily creates cylindrical pieces, it can also manufacture workpieces of different types.
CNC Grinding Machines – Perks and Benefits
In contrast with traditional grinding, CNC grinding delivers extremely refined finishes and light cuts to your metal workpiece. CNC grinding involves less skilled labor and minimal supervision and offers an extensive spectrum of benefits, some of which include –
- Production in Surplus Quantities
CNC grinding machines get the job done, regardless of the size and quantity of the component you wish to grind. These machines are remarkably efficient and can stay in operation all year-round. With CNC grinding machines, you can meet your personal and the client’s production demands at all times with no hassle.
- High Accuracy Levels
CNC grinding machines deliver exceptionally high levels of precision and accuracy and are programmable enough to produce superior-quality cuts. Due to the high efficiency of grinding machines in operation, the amount of waste generated gets reduced significantly, and components can be manufactured with high levels of precision.
- Software-Based Performance Boosts
CNC grinding machines operate using software, implying that you can boost the performance of your grinding machines by keeping the CNC software up-to-date. Software improvements help reduce cutting costs and make the grinding machines more time-efficient.
- Uninterrupted Production
Like other CNC and milling machines, the CNC grinding machines can operate 24×7, 365 days with no interruptions or downtime if proper maintenance is delivered. The only condition that can trigger stoppage is when performing regular maintenance activities.
Types of Grinding Processes
Surface grinding employs a vertical or horizontal axis grinding machine with a straight or a cup-type wheel and a circular table. The grinding wheel revolves around a spindle, and the workpiece gets mounted on either a reciprocating or rotary table that is brought in close proximity to the grinding wheel. There exist four types of surface grinders –
- Horizontal spindle/reciprocating table
- Horizontal spindle/rotary table
- Vertical spindle/reciprocating table
- Vertical spindle/rotary table
Cylindrical grinding involves grinding the cylinder’s outer surface, which might be contoured, tapered, or straight. This approach resembles the lathe-turning operations and is usually employed to replace the lathe when you desire high accuracy levels, superior finished surface, or the workpiece is hardened.
The grinding wheel rotates fast in the opposite direction and is close to the workpiece. The table and the workpiece reciprocate during contact with the grinding wheel. This process removes materials from the metal workpiece.
In centerless grinding, the need for center holes used for the work holding device gets eliminated. The workpiece is then made to rest on a work-rest blade that gets backed up by a second wheel, referred to as the regulating wheel.
The wheel’s rotation helps push the metal workpiece down the work-rest edge and against the rubber-bonded abrasive regulating wheel. This wheel rotates in the same direction as the grinding wheel and controls the workpiece’s longitudinal feed when set at a slight angle.
This grinding technique helps finish straight, tapered, or formed holes with high accuracy and holds the workpiece using a work-holding device, typically a chuck or a collet. The workpiece then gets rotated using a motorized headstock.
A separate motor rotates in the same direction as the component rotating with the grinding wheel. You can then adjust the rotation to vary the depth of cut and feed in and out of the workpiece.
This grinding technique involves using special types of procedures and grinders for specific processes. Some of them include –
- Tool and Cutter Grinders
These grinders sharpen milling cutters, reamers, taps, and other machining tool cutters. The general-purpose cutter grinder is the most versatile tool-grinding machine.
- Jig Grinding Machines
These machines accurately grind straight or tapered holes and come equipped with a high-speed vertical spindle for driving and holding the grinding wheel.
- Thread Grinding Machines
These grinders resemble cylindrical grinders and comprise a precision lead screw to produce the correct pitch or lead on a threaded workpiece.
CNC grinding employs abrasive techniques to remove materials from the workpiece. Regardless of the grinding technique involved, the end goal is to boost productivity and accuracy while minimizing waste.
Peter Jacobs is the Senior Director of Marketing at CNC Masters. He is actively involved in manufacturing processes and regularly contributes his insights for various blogs in CNC machining, 3D printing, rapid tooling, injection molding, metal casting, and manufacturing in general.