MFG 316 Chapter 5 //Jig Design

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Drill Jigs-most common used for drilling, tapping, reaming… Boring Jigs-used for boring holes to a precise size, bushing used on both ends. Cost of tool vs.
MFG 316 Chapter 5 //Jig Design A Jig is a workholder designed to locate, hold, and support a workpiece while guiding the cutting tool throughout its cutting cycle. Types of Jigs ⌧Drill Jigs-most common used for drilling, tapping, reaming… ⌧Boring Jigs-used for boring holes to a precise size, bushing used on both ends

General Considerations Cost of tool vs. benefit; should save more than cost ⌧complexity, location, number of holes, accuracy, number of parts to be made all must be considered

MFG 316 Chapter 5 //Jig Design Process Considerations Type of jig, number needed, processing steps First-operation jigs ⌧Used to put first holes into rough part to act as locators for subsequent operations. Adjustable locators and/or supports are generally used

MFG 316 Chapter 5 //Jig Design Developing the preliminary jig design

Product analysis considerations Operation considerations Machine considerations Operator considerations Production considerations Economic evaluation

MFG 316 Chapter 5 //Jig Design Machine Considerations Process usually dictates the machine used, but general requirements stay the same regardless of machine size Machine requirements ⌧Must be large and rigid enough to perform required operation ⌧suitable production capabilities and accuracy ⌧Safely accommodate workholding device ⌧Close to machines used for subsequent operations ⌧Specified cutting tools compatible with machine ⌧Standard size cutting tools used whenever possible

Specification sheet for each machine in shop Specification sheets for all standard cutting tools

MFG 316 Chapter 5 //Jig Design Other process considerations ⌧Repeatability between jigs ⌧Multiple jigs- same location point used in each of the jigs ⌧Stack or align parts to allow multiple part processes ⌧Consider step drilling large holes ⌧Chip control

MFG 316 Chapter 5 //Jig Design Drill Jigs  Correctly locate part wrt tool  Securely clamp and rigidly support part during operation  Guide the tool  Position and/or fasten the jig on a machine  Open and Closed

Advantages  Minimize tool breakage  Minimize possibility of human error  Permit use of less skilled labor  Reduce manufacturing time  Eliminate retooling for repeat orders

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MFG 316 Chapter 5 //Jig Design

MFG 316 Chapter 5 //Jig Design Template Drill Jigs

Advantages Simplest, easiest to build, least expensive

Disadvantages Not as foolproof, may not be as accurate, not good when used with RFS

MFG 316 Chapter 5 //Jig Design

MFG 316 Chapter 5 //Jig Design Universal Jigs Plastic Drill Jig Channel/tumble Jigs

MFG 316 Chapter 5 //Jig Design Plate Jigs

MFG 316 Chapter 5 //Jig Design Leaf Jigs

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MFG 316 Chapter 5 //Jig Design

MFG 316 Chapter 5 //Jig Design

Indexing Jig

MFG 316 Chapter 5 //Jig Design Drill Jig Bushings Headless press fit Head press fit Slip renewable, slip-fixed renewable Oil groove bushings Specials (consult vendor) Bushings for plastic & etc. Template Bushings Rotary Bushings Tips and accessories

MFG 316 Chapter 5 //Jig Design Chip clearance

Modified Vises Collet Fixtures Self centering Vises

MFG 316 Chapter 5 //Jig Design  Mounting of Bushings  Installation of Drill Bushings  Hole size and location

MFG 316 Chapter 5 //Jig Design Chip control to ensure correct operation ⌧use different length bushings ⌧burr clearance ⌧length 1 to 2 times the cutting tool

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MFG 316 Chapter 5

Jig Design Bushing must conform to irregular shaped pieces

MFG 316 Chapter 5 //Jig Design Add locators and supports ⌧must appear in all views as req’d

MFG 316 Chapter 5 //Jig Design Designing a Jig Sketch part ⌧all views required; scale, draw in red

MFG 316 Chapter 5 //Jig Design Add clamping devices ⌧show in all views; check for interference

Add tool body ⌧check for interference, redundant locators

MFG 316 Chapter 5 //Jig Design Add drill bushings ⌧check tolerances (50% of req’d tolerance); check clearances

MFG 316 Chapter 5 //Jig Design Check machine clearances ⌧final check

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MFG 316 Chapter 5 //Jig Design  Reaming General jig rules apply Closer tolerances required Provide support for reamer Enter bushing before part Remain piloted throughout Carbide for production runs

 Boring Jigs General jig rules apply Closer tolerances required Enter bushing before part Support on far end of jig Support on both ends of operation

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