CCD245 - Types and Functions

What is the difference between a jig and a fixture?

the jig guides the cutting tool while a fixture does not

what is the purpose of a jig

• used to control the location and/or motion of another tool

• primary purpose is to provide repeatability, accuracy and interchangeability in the manufacturing of products

• increase productivity through consistency, to do repetitive activities more precisely

what is the purpose of a fixture

• securely located and support the work ensuring that all parts produced using the fixture will maintain conformity and interchangeability

• reduces the requirement for skilled labor by simplifying how workpieces are mounted

what are drill jigs used for?

• drilling

• taping

• chamfer

• counterbore

• countersink

• reverse spotface

• reverse countersink

What are the types of jigs?

• template

• plate

• open

• channel

• leaf

• box

• sandwich

• trunnion

what is a template jig

plate made to shape and size of work piece with the required number of holes - suitable if only a few parts are to be made

what is a plate jig

in place of simple holes, drill bushings are provided

what is an open jig

the top is open and the work piece is placed on top

what is a leaf jig

sort of open jig, in which the top plate swings about a fulcrum point making loading and unloading easier

what is a box jig?

allows holes to be drilled on more than one place of the work piece

what is a trunnion jig

type of rotary jig used for odd shapes parts

what are classifications of fixtures

• wider scope of application than jigs

• designed for applications where cutting tools cannot be guided easily

• usually identified by the machine tool where they will be used

• use edge finders, center finders, or gauge blocks to position the cutter

  • main construction difference is mass due to tooling forces