Sunday, 24 May 2020
MECHANICAL INSTRUMENTS

Types of instruments required for align tests on Machine tools

The various equipment used for performing alignment tests are.

Test mandrels are two types they are

  1. Mandrels with taper shanks
  2. Cylindrical mandrels

Mandrels with taper shanks

In mandrels with taper shanks there deflection should be less than 0.65 µm, for those having working length of 75 mm and 5.8 µm for those having working length of 505 mm.

Cylindrical mandrels:

The cylindrical mandrels are generally used for checking true running of the spindle. Cylindrical mandrels have an accuracy of 3 microns over 300 mm length.

Straight edges and squares

The straight edges and squares instruments are cast iron or steel straight edges should be heavy and well ribbed.

Types of instruments required for align tests
Types of instruments required for align tests

Whereas, the standard squares should have wider bearing surfaces with a tolerance of ± 0.01 mm and precision of ± 0.005 mm.

Spirit level:

The spirit level type of equipment’s is used for high grade precession work. For each deflected division, the sensitivity ranges from 0.04 to 0.06 mm per meter. The two types of spirit levels i.e. horizontal type and frame are generally used for alignment tests.

Auto – collimator:

Auto – collimator is a very sensitive instrument generally used for testing alignment of long beds in horizontal, vertical or inclined planes.

Dial gauges:

These types of instruments are widely used in alignment tests with an accuracy of 0.01 mm. For fine measurements, the initial pressure should be from 40 to 100 gm and also a low pressure of 20 gm is desirable.

Waviness meter:

The waviness meter is widely used for recording and inspecting the surface waviness with a magnification of 50:1