“FLEXIBLE FIXTURING”

CONTENTS

Defination of “Manufacturing system”. What is ‘jigs’& ‘fixtures’. Defination of ‘flexibility’. What is ‘flexible fixtures’& why? Classification of modular fixtures. Design of modular fixture. Advantages of modular fixturing. Conclusion.

MANUFACTURING SYSTEM

JIG defination..

JIG:-a jig is element which guides the cutting tool, e.g drill bush

Jigs are workholders designed to hold, locate, and support a workpiece while guiding the cutting tool throughout its cutting cycle. Jigs can be divided into two general classifications: drill jigs and boring jigs. Of these, drill jigs are by far the most common. Drill jigs are generally used for drilling, tapping, and reaming, but also may be used for countersinking, counterboring, chamfering, and spotfacing. Boring jigs, on the other hand, are used mostly for boring holes to a precise

Fixtures are workholders designed to hold, locate, and support a workpiece during the machining cycle. Unlike jigs, fixtures do not guide the cutting tool, but they provide a means to reference and align the cutting tool to the workpiece

FIXTURE defination…

Fixture:-it references the cutting tool,

e.g clamps ,w/p holdings ,locators etc

FLEXIBILITY

It is the capability of producing different parts without major retoolings.

Jigs & fixtures play an important role in manufacturing .

Their cost are easy to justify when production runs are long & repeat orders.

Due to the short product life cycles ,design of fixture is problem?

FLEXIBLE FIXTURES

For smaller batch sizes modular fixtures is the answer.

Fixtures that allows reassembly of standard components into different shapes& sizes

Modular fixtures (flexible ) are temporary setups of standard components offer advantage of permanent tooling.

When to choose…?

Cycle of modular fixtures Modular fixtures consist of standard components

that provides support ,clamp, location to workpiece

Classification of modular fixtures

Two groups:- 1)Slot based:- parallel and perpendicular T-slots on the base plates 2)Hole based:-accurately positioned holes on the baseplates

Components of flexible fixtures

T-slot & hole modular fixture

Modular workholders

Design of modular fixture

There are three ways to design modular fixture:-

1)Designing by actually building fixture:-it requires only assembly of components,not machining,

once designers have rough concept in mind ,can build the fixture around sample part.

2)Preparing manual drawings:-

This can be speeded up by tracing the templates,when no sample part is avaible fixture can be assembled around template of part.

Design of modular fixture

3) Using CAD system:- This is most effective method for modular fixture design. A database representing all elements of the modular fixture system in either 2D or 3D is created by the user using a commercially CAD system

Example

figure shown a design example of a modular fixture for machining a virtual part in a horizontal milling machine. With an interactive CAD system the usual sequence of design is to first put the workpiece on the screen. The appropriate baseplate is then positioned under the part. Next, the designer

selects the necessary components needed to support, locate and clamp the part from the component database.

ADVANTAGES OF CAD SYSTEM

Using a CAD system to perform a modular fixture design, not only reduces the time required for the design, but also allows freedom to designer to experiment several design alternatives before arrive to an optimal solution.

ADVANTAGES OF FLEXIBLE FIXTURING It reduces the set up time. Cost required to design & fabricate special

purpose fixtures is less due to standard components.

Reduce time & cost associated with storing & retriving the fixtures between different machining operations.thats why it is used in batch production.

CONCLUSION

Traditional flexible fixtures design & assembly process greately improved by using CAD approach i.e. design of flexible fixtures by CAD system.

Fluidised Bed Fixturing

Pressurised air is used to held the job Research stage

Adhesives Fixturing