Double Station Vise, also known as synchronous vise or self-centering vise, has a fundamental difference in its core working principle from the traditional single-action vise. It does not rely on the unidirectional movement of a single movable jaw to clamp the workpiece, but rather achieves the synchronous movement of two movable jaws towards or opposite directions through ingenious mechanical design.
I. Working Principle: The core of synchronization and self centering
Core transmission mechanism: Bidirectional reverse lead screw
Inside the body of the double station vise, there is a precision lead screw processed with left and right reverse threads.
When the operator turns the handle, the lead screw rotates accordingly. The two nuts (or jaw seats) installed on the left and right reverse threads will generate synchronous and symmetrical linear motion due to the opposite direction of the threads.
When the lead screw rotates clockwise, the two movable jaws move synchronously towards the center to achieve clamping.
The lead screw rotates counterclockwise, and the two movable jaws move away from the center synchronously to achieve release.
Self calming function
Since the two jaws move strictly synchronously, the centerline of the workpiece will always be fixed on the geometric centerline of the double-station vise.
This means that whether it is clamping round bars of different diameters or symmetrical processing work that requires a center as the reference, the center can be automatically found without additional measurement or alignment, greatly improving accuracy and efficiency.
Anti-workpiece floating mechanism (corner fixation design)
This is the key technology of high-quality double-station vise. During the clamping process of the jaws, the horizontal clamping force is decomposed into a horizontal backward force and a vertical downward force through a special wedge-shaped block or inclined plane mechanism.
This downward component force can firmly press the workpiece against the positioning surface at the bottom of the vise or the parallel shims, effectively overcoming the upward cutting force generated during heavy-duty milling and drilling, preventing the workpiece from vibrating, shifting or floating up, and ensuring the consistency of the processing depth dimensions.
II. Technical Features and Performance Parameters of Double Station Vise
1. Technical features:
High efficiency: It can simultaneously clamp two identical workpieces for processing, or clamp a long workpiece at both ends at the same time, enabling each tool pass of the machine tool to generate double or higher output and significantly reducing clamping time.
High precision: Self-centering accuracy: The repeat positioning accuracy is extremely high, usually reaching ±0.01mm or even higher (such as ±0.002mm), ensuring the consistency of batch processing.
High rigidity：
The main body material is mostly made of high-strength ductile iron (FCD550/600) or alloy steel, and has undergone stress relief treatment to ensure no deformation or vibration under huge clamping forces.
Guide rail structure: The sliding guide rail undergoes high-frequency quenching or nitriding treatment, with a surface hardness of over HRC45, ensuring an extremely long wear-resistant service life.
III. Operating Specifications for Double Station Vise
Installation：
Firmly install the double station vise on the machine tool worktable and ensure that the bottom surface and positioning keyway are clean and free of foreign objects. Use a torque wrench to tighten the T-slot nuts in diagonal sequence in multiple steps to ensure that the vise is evenly stressed and does not deform due to installation stress. After the first installation or position change, use a dial indicator to align the plane and side of the fixed jaw to ensure its parallelism and perpendicularity with the X/Y axis of the machine tool.
Clamping workpieces：
Cleaning: Always keep the vise body, jaws, workpieces and shims clean.
When using shims: During processing, it is essential to use ground parallel shims to raise the workpiece, ensuring that the processing area is higher than the jaw to prevent the tool from cutting into the jaw. The heights of the shims should be consistent.
Reasonable clamping: The clamping force should be appropriate. If it is too small, it will cause the workpiece to loosen; if it is too large, it will cause the vise and the workpiece to deform, and even damage the precision lead screw. For thin-walled or easily deformable workpieces, a red copper sheet should be placed between the jaw and the workpiece.
Knocking alignment: After placing the workpiece, gently tap the upper surface of the workpiece with a copper hammer or plastic hammer to ensure that the bottom surface is fully in contact with the shims and eliminate the gap.
Post time: Aug-19-2025
