Everything You Need To Know About Electromagnetic Chucks

By Author: JASON CHEN
Total Articles: 41
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Electromagnetic chucks can result in variable holding power, which to support a wide range of machining applications greatly improves their ability.

Magnetic chucks are designed in a way so that they can hold Ferro-metallic workpieces with a strong, uniform holding force. They contain accurately centered permanent magnetic face whose working takes place in conjunction with an operator actuated permanent or electromagnet. To create a secure anchor for the workpiece the workpiece closes the magnetic loop.

Electromagnetic Chuck Operation

Electromagnetic chucks are constructed with electrical coils wound around a steel core embedded in the chuck. To energize the electromagnetic field, a chuck controller is used to generate a variable DC voltage in the chuck's coils. The coil's electromagnetic field causes particles within the Ferro-metallic workpieces to be aligned in a common direction. This alignment creates the electromagnetic holding force between the workpiece and the chuck.

The chuck's poles are magnetic as long as the voltage is applied. The Magnetic Welding Holder ...
... can adjust the controller's DC voltage to vary the strength of the magnetic field, which, in turn, provides the variable holding force.

The Variable Holding Power Advantage

The chuck's ability is greatly improved by variable holding power to support a wide range of machining applications that include milling, shaping, cutting, EDM, high-speed cutting operations, and thin work for grinding. For automation purposes, electromagnetic chucks can easily be interfaced with machine centers.

For thin work applications, variable holding power is critical. For example, when a certain part that is to be machined is a thin-0.25 inch or thinner-and as one of a stack of similar parts the part is presented to a machine operator, then there is a need to lift the piece from the stack. However, with the variable voltage control, an electromagnet allows the operator to decrease the magnetic strength to the point where from a stack of parts only one piece at a time can be lifted.

Permanent Magnet vs. Electromagnet

To produce a magnetic holding force both permanent magnets and electromagnets can be used. On both machining applications and externalities, the choice of a permanent or electromagnetic design is dependent. Since there is no requirement for electric power for permanent magnets, they are best used when there's no power available or it is unreliable. On the other hand, the magnetic field of permanent magnetic chucks cannot be adjusted, which for machining applications can be a drawback that requires variable holding power.

Shop Safety

Over permanent magnetic chucks, the variable holding power of electromagnetic chucks gives it an advantage. But both on both machining application and shop safety their selection depends. A power failure can introduce a worker safety concern; however, electromagnets need constant power to operate. To address these concerns, uninterruptible power supplies, power conditioners, and battery backup systems can be integrated into the machining operations but on the design of a particular machining application, the ultimate decision depends.