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