The fixture should be compact.

The outer contour size of the fixture should be as small as possible, the weight should be as light as possible, and the center of gravity of the fixture should be as close to the rotating shaft as possible to reduce inertia force and rotating torque.

2. Balance structure should be considered in fixture design.

Eliminate the possible imbalance in fixture rotation and avoid the influence of vibration on workpiece processing quality and tool life. Especially the angle iron lathe fixture is the most prone to such problems. There are two main methods for balancing measures, namely, setting a counterweight and adding a weight-reducing hole.

3. The clamping device of the fixture should strive to clamp quickly and reliably.

Attention should also be paid to the tendency that the inertia force of fixture rotation may reduce the clamping force. In order to prevent the clamping element of the fixture from loosening during rotation, a reliable self-locking structure should be designed

4. The positioning and connection between fixture and lathe spindle should be accurate and reliable.

The axis of rotation of the connecting shaft or connecting disk (transition disk) should have as high concentricity as possible with the axis of the lathe spindle. For the fixture with small outer contour size, the Morse taper handle can be used to connect with the taper hole of the machine tool spindle; For the fixture with large outer contour size, it can be connected with the main journal of the machine tool through a specially designed transition disc. No matter which connection method, we should pay attention to the firm connection and avoid looseness. Especially when the spindle rotates at high speed and brakes suddenly, there should be an anti-sending device between the fixture and the spindle.

5. The size of the workpiece cannot be greater than the rotating diameter of the fixture.

All parts and devices on the fixture should not be larger than the rotating diameter of the fixture body. The parts close to the outer edge of the fixture body should avoid the protruding part as far as possible, and a protective cover can be installed outside the rotating part if necessary.