A vacuum table uses negative pressure to secure material quickly and evenly to the working surface of a CNC router. It allows sheet materials to be machined without numerous mechanical clamps that could interfere with the cutting tool.
How does vacuum workholding operate?
A vacuum pump removes air from beneath the material. The pressure difference presses the workpiece against the table and helps prevent movement during machining.
The working surface is usually divided into separate zones. The operator activates only the areas beneath the workpiece, reducing unnecessary air leakage.
Benefits of a vacuum table
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rapid loading and replacement of material,
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even holding of large sheets,
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unobstructed access to the material surface,
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fewer mechanical clamps,
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higher productivity,
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efficient full-sheet machining.
What determines holding force?
The result depends on the workpiece surface area, pump performance, system sealing and material permeability. A large, flat and non-porous sheet is easier to hold than a small or porous component.
A permeable MDF spoilboard is often used when cutting through sheet material. It must be flat and resurfaced regularly.
When is additional workholding required?
Vacuum alone may not be sufficient for small parts, narrow components, porous materials or operations generating high cutting forces. Mechanical stops, clamps, tabs in the CNC program or another combined workholding method may then be required.