Table of Contents
How do you use a sine bar step by step?
Sine Bar Usage Always use a perfectly flat and clean surface plate. Place one roller on the surface plate and the other roller on the slip gauge block stack of height H. Let the sine bar be set to an angle ϴ. Then sin(ϴ) = H/L, where L is the distance between the center.
How a sine bar is used to measure angles?
Angles are measured using a sine bar with the help of gauge blocks and a dial gauge or a spirit level. The aim of a measurement is to measure the surface on which the dial gauge or spirit level is placed horizontally. At this position, the top surface of the sine bar is inclined the same amount as the wedge.
Why there are holes in sine bar?
Sine bar consists of a precisely machined corrosion resistant chrome steel. It is essentially hardened and stabilized. The relief holes are drilled into the body of sine bar to reduce the weight, and to facilitate handling.
What are sine plates used for?
The sine bar or sine plate is used for accurately setting up work for machining or for inspection. Gage blocks are usually used for establishing the height. Rule for determining the height of the sine bar setting for a given angle: multiply the sine of the angle by the length of the sine bar.
How do you calibrate a sine bar?
This is typically achieved using gage blocks. It’s important to ensure the center to center distance between cylinders, the radius of each cylinder, and the parallelism of the flat surface to the radius centers are all known since the sine bar accuracy relies on the precise measurements of these objects.
What precautions should be taken while using sine bars?
Precautions in use of sine bars. (i) The sine bar should not be used for angle. (ii) A compound angle should not be formed by mis-aligning of workpiece with the sine. (iii) Accuracy of sine bar should be ensured. (iv) As far as possible longer sine bar should be used since many errors are reduced by.
Why sine bars are not used for large angle measurements?
Why is a sine bar not suitable for measuring angle above 45? The sine bars become inaccurate as the angle exceeds 45° because the bar(product) is physically clumsy to hold at that position and even a slight error of the sine bar can cause large angular errors. 4.
Which of the following is used in making of sine bars?
Sine bars are made from high chromium, high carbon, corrosion resistant steel, ground, hardened and stabilised.
Why is sine bar limited to 45 degrees?
Explanation: A sine bar is used to measure angles based on the sine principle. Therefore, the error in angle measurement dθ, due to an error dh in height h is proportional to sec θ. Now sec θ increases very rapidly for an angle greater than 45°.
Why rollers are provided in sine bar?
Construction of Sine Bar: The sine bar has a gauge body made of a rigid material such as steel. There are two rollers at the end of the steel bar. The rollers are of equal diameter, and the axes of these rollers are parallels to each other. Relief holes are provided to reduce the weight of the bus sine bar.
What is least count of sine bar?
Answer: Accuracy up to 0.01mm/m of length of the sine bar can be obtained.
What is the difference between gauging and measurement?
As nouns the difference between measure and gauge is that measure is the quantity, size, weight, distance or capacity of a substance compared to a designated standard while gauge is a measure; a standard of measure; an instrument to determine dimensions, distance, or capacity; a standard.
What is sine table in metrology?
Sine plates and tables are used for checking simple or compound angular relationships of one face or diameter to another to a high degree of accuracy. They can also be used to produce precise angular faces or diameters by grinding, jog boring or light machining in simple or compound planes.
What is a machinist sine plate?
A sine plate is a precision measurement tool built of finely ground or lapped steel, used to measure angles for parts or for measuring angled parts.
What is sine Centre Mcq?
Explanation: A sine bar with block holding centres is known as sine centre. It can be rigidly clamped and adjusted in any position. Sine centres can be used for inspection of the conical objects between centres.
What is the principle followed by sine bar?
The principle of operation of the sine bar is based on the law of trigonometry. If one roller of sine bar is placed on the surface plate and the other roller is placed on the height of slip gauges, then the structure formed by the sine bar, surface plate, and slip gauges forms a triangle.
What are the various factors on which the accuracy of the Sinebar depends?
Accuracy of Sine bar depends on: Equality of size rollers. Centre distance of rollers (must known). Parallelism of roller axes to each other. Parallelism of roller axes to upper surface of bar.
How accurate are dial indicators?
The most common accuracy for a Dial Indicator is 0.001″.
What is the maximum recommended angle to which a sine bar can be set?
Sine bar is more accurate for angles between 15° to 45°, below and above to this limit, angles measured are not much more accurate. If a sine bar is to be accurate than the following properties must exist: (i) The distance between centres (L) must be precisely known.
What are the different uses of sine bar and angle gauges why the sine bar is not preferred for measuring the angle larger than 45?
The accuracy of the angle set by a sine bar depends on the the errors in its important dimensions such as error in distance between roller centres, error in combination of the slip gauges used for setting, error in parallelism between gauging surface and plane of roller axes etc.
Which is more accurate sine bar or bevel protractor?
The sine-bar is almost as accurate as the bevel protractor. Gage-block precision angles can be used to inspect angles to which accuracies.
How many divisions are graduated on thimble?
16. How many divisions are graduated on thimble? Explanation: Graduation lines should be clearly engraved. 50 divisions are graduated on thimble each representing 0.01mm.
