Home | Engineering | Sine bar

Mechanical - Metrology and Measurements - Linear and Angular Measurements

Sine bar

   Posted On :  23.09.2016 01:50 pm

Sine bars are always used along with slip gauges as a device for the measurement of angles very precisely. They are used to 1) Measure angles very accurately. 2) Locate the work piece to a given angle with very high precision.

SINE BAR

 

Sine bars are always used along with slip gauges as a device for the measurement of angles very precisely. They are used to

 

1) Measure angles very accurately.

 

2) Locate the work piece to a given angle with very high precision.

 

Generally, sine bars are made from high carbon, high chromium, and corrosion resistant steel. These materials are highly hardened, ground and stabilized. In sine bars, two cylinders of equal diameter are attached at lie ends with its axes are mutually parallel to each other. They are also at equal distance from the upper surface of the sine bar mostly the distance between the axes of two cylinders is 100mm, 200mm or 300mm. The working surfaces of the rollers are finished to 0.2µm R value. The cylindrical holes are provided to reduce the weight of the sine bar.


 

 

Working principle of sine bar


The working of sine bar is based on trigonometry principle. To measure the angle of a given specimen, one roller of the sine bar is placed on the surface plate and another one roller is placed over the surface of slip gauges. Now, ‘h be the he slip gauges and ‘L’ becenters,thenthe angledistancecalculatedas between


 

 

Use of Sine Bar

 

 


Locating   any’   work   to   a   given   angle

1)      Before checking the unknown angle of the specimen, first the angle (0) of given specimen is found approximately by bevel protractor.

 

2)      Then  the  sine  bar  is  set  at  angle  of  0  and  clamped on the angle plate.

 

3)      Now, the work is placed on the sine bar and the dial indicator set at one end of the work is moved across the work piece and deviation is noted.

 

4)      Slip gauges are adjusted so that the dial indicator reads zero throughout the work surface.

 


 

 

Limitations of sine bars

 

1) Sine bars are fairly reliable for angles than 15°.

 

2) It is physically difficult to hold in position.

 

3) Slight errors in sine bar cause larger angular errors.

 

4)                A difference of deformation occurs at the point of roller contact with the surface plate and to the gauge blocks.

 

5) The size of parts to be inspected by sine bar is limited.

 

Sources of error in sine bars

 

The different sources of errors are listed below:

 

1) Error in distance between roller centers.

 

2) Error in slip gauge combination.

 

3) Error in checking of parallelism.

 

4) Error in parallelism of roller axes with each other.

 

5) Error in flatness of the upper surface of sine bar.


 

Tags : Mechanical - Metrology and Measurements - Linear and Angular Measurements
Last 30 days 1255 views
Related words :

What is Sine bar Define Sine bar Definition of Sine bar where how meaning of Sine bar lecturing notes for Sine bar lecture notes question and answer for Sine bar answer Sine bar study material Sine bar assignment Sine bar reference description of Sine bar explanation of Sine bar brief detail of Sine bar easy explanation solution Sine bar wiki Sine bar wikipedia how why is who were when is when did where did Sine bar list of Sine bar school assignment college assignment Sine bar college notes school notes kids with diagram or figure or image difference between Sine bar www.readorrefer.in - Read Or Refer

​Read Or Refer

OTHER SUGEST TOPIC

Recent New Topics :