A bevel protractor is a precision measuring instrument used in woodworking and engineering to accurately measure and set angles. Its base is on the bottom side of the angle, while the blade moves to match the opposing side. This versatile tool is essential for tasks requiring precise angle measurements, such as layout and machining of components, alignment of machine tools, and creating intricate geometric shapes.
The bevel protractor is often used with jigs and other objects, ensuring accurate and precise measurements in various fields. Well, in this reading, we’ll explore what a bevel protractor is, its applications, parts, diagrams, types, ranges, and how it works. We’ll also explore its advantages and disadvantages.
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What is a Bevel Protractor?
A bevel protractor is a precision measuring tool used in engineering and machining, particularly in metalworking and woodworking. It features a pivoting blade and a graduated dial, allowing for precise angle measurements.
This versatile tool is essential in precision engineering and layout work, particularly for beveled and angular workpieces. The bevel protractor is a circular scale marked with gradations and an arm, typically pigmented, used for precise measurement and construction of angles.
The standard unit of measurement in geometry is degrees. The bevel protractor’s least count is often around 5 minutes (1/12th of a degree) or 0.0833 degrees. Its sophisticated versions, like the bevel protractor, incorporate one or two swinging arms for angle measurement. With a minimum increment of 5 minutes, it is suitable for determining the angles of various workpieces, including jigs.
A bevel protractor is a graduated circular protractor with one pivoted arm, used for measuring or marking off angles. It has wide application in architectural and mechanical drawing, but its use is decreasing with the availability of modern drawing software or CAD. Universal bevel protractors are also used by toolmakers, as they measure angles by mechanical contact.
The bevel protractor consists of a beam, a graduated dial, and a blade connected to a swivel plate with a Vernier scale. To measure an angle between the beam and blade of 90° or less, the reading can be obtained directly from the graduation number on the dial. The spaces on the main scale and Vernier scale are numbered both to the right and to the left from zero, allowing for any angle measurement.
What is The Applications of Bevel Protractor?
Bevel Protractor is a powerful tool used in various applications, including engineering, construction, and quality control inspections. It is used to measure and set precise angles in various components, create geometric shapes, verify the accuracy of angles in workpieces, assist in fabrication of jigs and fixtures, and facilitate angle measurements in metalworking and woodworking projects. Bevel Protractor is particularly useful for checking V Blocks, the inside beveled face of the ground surface, and measuring acute angles.
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Parts of a Bevel Protractor
The various parts of a bevel protractor are swivel plate, magnifying glass, vernier scale, angle-lock screw, dial, dial scale, blade, blade-lock screw, and stock.
The bevel protractor is a precision tool that utilizes a pivotal swivel plate and vernier scale to measure angles. The swivel plate rotates smoothly on the dial, providing precise angle measurements. The vernier scale, affixed to the swivel plate, is crucial for minute angle measurements, representing 60 minutes. The vernier scale is marked at every tenth degree and is divided into four 90-degree segments.
The dial, the foundational base of the bevel protractor, hosts the primary scale, the dial scale, which has a graduated angle measurement range from 0 to 360 degrees. The blade, crafted from high-carbon steel, is a thin, elongated component that aligns parallel to the stock, with its zero corresponding to the main or dial scale. The blade-lock screw secures the blade at a specific position, especially when determining the required blade length along the workpiece’s surface.
The stock, an integral part of the dial assembly, moves in relation to the blade, causing changes in the angle value displayed on the dial scale. During angle measurement, the workpiece is placed in contact with the stock on one side, while the other side aligns with the blade, ensuring accurate angle determination. The bevel protractor’s accuracy and efficiency are ensured by its swivel plate, vernier scale, and blade.
Diagram
Types of Bevel Protractor
Bevel protractors are versatile tools used for measuring angles. They come in various types, including Universal, Digital, and Optical. Universal bevel protractors have a circular scale, while Digital protractors offer digital readouts for convenience. Optical clinometer protractors use optical technology for angle measurement.
A Vernier bevel protractor is a precision measuring instrument that accurately measures and sets angles using a Vernier scale. It is suitable for a wide range of angular measurements, including those in machining and engineering applications.
A universal protractor, also known as a universal bevel protractor, is a versatile tool designed to measure and set angles in various planes, including horizontal and vertical. It usually consists of two arms, one of which can rotate around the base, allowing measurements in different directions.
Optical protrators, on the other hand, are advanced instruments used for highly precise angle measurements, employing optical principles like interference patterns or optical gratings. They provide non-contact measurements and are suitable for both small and large angles, making them essential tools in fields like optics, astronomy, and precision engineering.
How Does A Bevel Protractor Works?
The Vernier Bevel Protractor is a tool used for measuring the angle between two points on a circular plate. The Base Plate acts as one of the working edges, while the other working edge is the blade held on the circular plate.
The adjustment blade can be rotated along with the circular plate on the main body, allowing the vernier scale to be rotated on the graduated main scale. The Vernier scale has 12 divisions on each side of the center zero, representing 24 divisions. One division equals 60 minutes, while the same portion is represented as 23° on the main scale.
The zero line on the vernier scale moves on the main scale, indicating the reading on the main scale. The Vernier scale reading coincides with the divisions on the main scale, and using these values and the least count of the Vernier bevel protractor, the reading can be calculated.
How to Use it
To use the Bevel Protractor, unscrew the large clamp on the front part of the protractor, allowing the blade to swivel. Align the base on one side of an angle and swivel the blade for the other side. Tighten the clamp and spot the zero on the vernier scale, which is smaller on the inner side of the protractor. Read the number of degrees on the main scale, directly above the zero on the vernier scale.
Range of Bevel Protractor
The bevel protractor is a versatile tool designed for precise measurement of angles, with a range of 0 degrees to 360 degrees. It features a beam, graduated dial, and a blade connected to a swivel plate. The swivel plate’s edge marks coincide with the 0 lines on the graduated dial when parallel.
The reading for angles between the beam and blade is based on the graduation number on the dial, while for angles over 90 degrees, the dial’s number must be subtracted from 180 degrees. The bevel protractor is particularly useful for precise testing and establishing close tolerances.
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Advantages and Disadvantages of Bevel Protractor
Bevel protractors are precision measuring instruments that offer high accuracy in angle measurement, making them suitable for various industries and applications. They are easy to use and read, durable, and suitable for a wide range of angles. They are essential for quality control and inspection processes, supporting precise layout and machining tasks, and creating and verifying specific angles in woodworking and metalworking.
However, bevel protractors have some disadvantages, such as a limited measurement range (360 degrees or less), limited accuracy due to operator skill, and potential parallax error. Some modern bevel protractors incorporate anti-parallax features to mitigate these issues. Additionally, they may not be suitable for measuring angles in hard-to-reach or confined spaces, as they can be relatively large and may not be practical for certain applications.