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Hasitha Wipulaguna
What is Jig/ Fixture ? Types of Jigs / Fixtures The Purpose of use of a Jig or a Fixture Design considerations of a Jig/Fixture Illustrate the method of
Locating Supporting Clamping Guiding
JIG-a device that automatically determines location dimensions for machining or assembly. A jig can assist in guiding tools and will clamp the workpiece.
Fixture- A device which clamps work during machining.
Plate Jig
Channel Jig
Pot Jig
Milling Fixtures
To eliminate marking, punching, positioning, alignments.
Easy, quick and accurate locating, supporting and clamping blank in alignment of the cutting tool.
Guidance to the cutting tool like drill, reamer etc
Easy, quick and consistently accurate locating of the blank in the jig or fixture in reference to the cutting tool.
Providing strong, rigid and stable support to the blank.
Tool guidance for slender cutting tools like drills and reamers etc.
Easy and quick loading and unloading the job to and from the jig or fixture.
Use of standard parts as much as possible
Locate 3-2-1 Principle
One of the basic fixturing methods is the 3-2-1 system. This method cancels the twelve degrees of freedom of a part and positions it in three perpendicular planes.
3-2-1 Principle(3) Three points establish base plane(2)Two points establish vertical plane for reference(1) One point in third plane positively locates part
SupportDeflection due to Supportive forces
Recess in long span supporting
Support Methods of Supporting Workpieces
supporting on vices supporting on flat surfaces / blocks supporting by fixed pins supporting (and locating) on vee blocks and
mandrels
Clamping clamping need to be strong, rigid enough to
hold the blank firmly. should be easy, quick and adequate. clamping should be such that it is not
affected by vibration, chatter or heavy pressure.
What is Jig/ Fixture ? Types of Jigs / Fixtures The Purpose of use of a Jig or a Fixture Design considerations of a Jig/Fixture Illustrate the method of
Locating Supporting Clamping Guiding
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