What is the 321 Principle?

What is the 321 Principle?

The 3-2-1 principle of location (six point location principle) is used to constrain the movement of workpiece along the three axes XX, YY, and ZZ. This is achieved by providing six locating points, 3 pins in base plate, 2 pins in vertical plane and 1 pin in a plane which is perpendicular to first two planes.

What do you understand by locating principle?

BASIC PRINCIPLES OF LOCATING To perform properly, workholders must accurately and consistently position the workpiece relative to the cutting tool, part after part. To accomplish this, the locators must ensure that the workpiece is properly referenced and the process is repeatable.

What is the 3-2-1 principle of jig design?

The 3-2-1 method is a work-holding principle where three pins are located on the 1st principle plane, i.e., either XY, YZ, ZX. And two pins are located on the 2nd plane perpendicular to the 1st plane, and at last, one pin on the plane is mutually perpendicular to the 1st and 2nd planes.

What are locating devices?

“Locating Devices” describes the components used to position a workpiece in a workholding device. Locating is a crucial part of effective workholding. Locators come in a wide range of available types with various features. Common locators include pins, buttons, and pads.

What is jig and fixture?

The Major Difference between Jig and Fixture is that Jig is a type of tool used to control the location or motion of another tool. Whereas Fixture is a support or work holding device used to hold work in place. In metal and woodworking, both jigs and fixtures are essential tools used.

What is locator in jig and fixture?

Locator: device to establish and maintain position of. a part in a jig or fixture.

What is the difference between secondary and redundant locators?

What is the difference between secondary and redundant locators? Secondary locators are used to supplement primary locators. Redundant locators use more than one locator to restrict the same direction of movement.

When 3 2 1 principle in used to support and locate a three dimensional work piece during machining the number of degrees of freedom that are restricted is?

[1] It is also known as a six-pin or six-point location principle. In this, the three adjacent locating surfaces of the blank (workpiece) are resting against 3, 2, and 1 pin respectively, which prevent 9 degrees of freedom.

What is shimming in BIW?

Shims are typically used in order to support, adjust for better fit, or provide a level surface. Shims may also be used as spacers to fill gaps between parts subject to wear. Shims are the small parts which comes with the thickness of 0.1mm,0.2mm,0.5mm,1.0mm etc.

What is the purpose of locator?

A locator map, sometimes referred to simply as a locator, is typically a simple map used in cartography to show the location of a particular geographic area within its larger and presumably more familiar context.

What are the different types of locators?

The different locators in Selenium are as follows:

• By CSS ID: find_element_by_id.
• By CSS class name: find_element_by_class_name.
• By name attribute: find_element_by_name.
• By DOM structure or xpath: find_element_by_xpath.
• By link text: find_element_by_link_text.
• By partial link text: find_element_by_partial_link_text.

What is jig and fixture difference between jig and fixture?

A jig guides the cutter to work at a predefined location on a workpiece. It also supports and locates the part. The fixture, however, only secures, supports and locates the workpiece. It does not guide the machine part.

What is the 3-2-1 principle of location?

The 3-2-1 principle of location (six point location principle) is used to constrain the movement of workpiece along the three axes XX, YY, and ZZ. This is achieved by providing six locating points, 3 pins in base plate, 2 pins in vertical plane and 1 pin in a plane which is perpendicular to first two planes.

How many degrees of freedom does the 321 principle lock?

In 321 principle, the primary (usually a plane) locks 3 degree of freedom, 2 rotations and 1 translation respectively. The secondary locks another 2 degrees of freedom, 1 translation and one rotation. Finally the tertiary datum locks the final translation.

What is the 321 principle of GD & T?

The 321 principle one of the methods how the parts degree of freedoms are arrested. In 321 principle, the primary (usually a plane) locks 3 degree of freedom, 2 rotations and 1 translation respectively.

Which is an example of the principle of location?

The principle of location is being discussed here with the help of a most popular example which is available in any of the book covering jigs and fixtures. It is important that one should understand the problem first.