Complete Edm Handbook

by Sommer, Carl; Sommer, Steve

• ISBN13: 9781575373027
• ISBN10: 1575373025
• Format: Hardcover
• Copyright: 2005-07-30
• Publisher: Advance Pub

Summary

Carl Sommer, owner and president of Reliable EDM Corp. in Houston, Texas, has a wide and varied background in the machine tool trade. Steve Sommer, M. E. vice president, has a mechanical engineering degree, and had experience as a tool and die maker, and a thorough knowledge of computer programming and the wire EDM process. You'll discover in this book: Fundamentals of Wire EDM, How to Profit With Wire EDM, Proper Procedures, The Wire EDM Process, Many Cost-Saving Ideas, The Tool and Die revolution, building One-Piece Stamping dies, Application for Design Engineers, Production Wire EDM, and Practical Applications for Wire EDM.

Author Biography

The father and son team, Carl, Steve, and Phil Sommer, own and operate Reliable EDM in Houston, Texas. They specialize in all types of EDM (electrical discharge machining) wire EDM, ram EDM (also known as plunge, and sinker EDM), and small hole EDM. They are the largest wire EDM job shop west of the Mississippi River. Carl Sommer, president, has witnessed firsthand the dramatic changes in the machining field. In 1949, he started working in a machine shop in Brooklyn, NY. It was not long before Carl began working as an apprentice tool and die maker where he learned to make dies with hand files and filing machine. Then he found a job in precision tool and die shop. The owner of the precision tool and die shop sold it, and in the new company Carl gained broad and valuable experience in virtually all areas of the machining fieldùprecision tools and dies, fixtures, and short run production from such companies as IBM, Gyrodyne, Thikol, Fairchild Stratus, Remington, and Sikorsky Helicopter. He operated all machines, worked in the inspection department, and made precision dies where parts were ground to within .0001 (.0025 mm). (That's less than 1/20th the thickness of a human hair.) Then Carl became a foreman for a tool and die and stamping company.Carl decided to become a New York City high school teacher. So for most of the 1970s, he worked as a New York City high school teacher in the industrial arts department. During this time he also conducted extensive research into the problems facing America's educational institutions. This research, as well as proposed solutions, culminated in the writing the book, Schools in Crisis: Training for Success Or Failure? Carl moved to Houston, Texas in 1978. The pay was so poor for teachers, that he re-entered the machine tool industryùfirst as a tool and die maker, then as a tool designer for one of Houston's largest tool and die and stamping shops. After six months Carl advanced to the position of operations manager, and for 5 1/2 years managed the entire company. At this shop the stamping dies were milled or ground. When the company purchased a wire EDM machine, it revolutionized their tool and die making. Now the most difficult shapes could be machined accurately into hardened tool steel.In 1986, Sommer started Reliable EDM with his two sons. One of the major needs he saw was that individuals needed to be educated concerning the benefits of wire EDM, so he sent information to companies describing the process and the capabilities of wire EDM. Within four years, they became the largest wire EDM job shop in Texas; within nine years, they became the largest wire EDM job shop west of the Mississippi River. In the beginning Carl operated the EDM equipment, and with his machining background built all sorts of fixtures for the EDM shop. With his company being profitable, Carl began to follow his dreams of writing children's books that would teach children the principles on how they can become successful. He has written 20 children's books that have won numerous awards. He is also writing three large literacy programs, Reading Success, a phonics literature-based reading program for adults, Reading Adventure, a phonics literature-base reading program for children, and Number Success, a practical math program from addition to trigonometry (this math program will be on 47 DVDs). For more information go to www.advancepublishing.com.Steve Sommer M.E., vice president, received his mechanical engineering degree from the University of Houston. When Steve graduated from college, the oil crisis hit Houston and he couldn't find a job as an engineer. While going to school he worked as a machinist, so with his machinist background he found a job working as a tool and die maker. While working as a tool and die maker, he was asked to run the EDM department. His experience in engineering, machining, tool and die making, and EDMing continues to be a valuable asset for Reliable EDM. Steve has a thorough knowledge of the machining trade, computer programming, and the EDM process. He has worked over 20 years in programming and operating EDM equipment.Phil Sommer, vice president of operations, has a degree in business administration and heads the EDM operations. He also has extensive EDM experience. Phil has years of experience in running an EDM shop and dealing with customers.The family team built their business on following the Golden Rule of doing to others what one would like being done to them. Following the Golden Rule and the exceptional experiences of this father-and-son team are the major reasons for Reliable's remarkable growth and success. With their machining background, they have modified EDM machines where they can cut parts 36" (914 mm) tall, and wire EDM a single-hole cavity in tubes up to 22" (559 mm) deep. They do all kinds of work for aerospace, defense, petroleum, plastics, electronics, medical and many other industries. Since their company uses all the EDM equipment discussed in this book, Carl and Steve are uniquely qualified to write The Complete EDM Handbook. In regard to the first book Carl and Steve wrote, Wire EDM Handbook, Jack Sebzda, editor in chief of EDM Today, stated: FINALLY...A comprehensive, professionally written book, all about Wire EDM is available to the EDM community!...The 'Wire EDM Handbook' puts a wealth of practical, to-the-point information at your fingertips. Written for people at every level of EDM experience, this professional, hard cover book, belongs in every EDM shop." (EDM Today has repeatedly advertised and sold this book for many years." Wire EDM Handbook went through four editions and has been used as a textbook in US colleges and technical schools. When this book was first published, an EDM salesperson who travelled to Germany told Carl that there was a book in Germany on wire EDM, but our book "makes money." This was a high compliment. Our aim in writing The Complete EDM Handbook is to provide practical advice for all the EDM processes. We have seen many articles with all sorts of technical information that we in the shop would never use. We have avoided this in writing this book.There is information in this book that can literally save companies thousands of dollars. Since Carl has worked as a tool and die maker, tool designer, and operations manager of a large tool and die shop, his information alone in chapters 7 and 8 can save companies tens of thousands of dollars if implemented. Throughout this book there's much practical advice for everyone. For more information, feel free to contact them.Reliable EDM 6940 Fulton St.Houston, TX 77022 800-WIRE EDM (800-947-3336) Tel. [phone] Fax [phone] Web site: www.ReliableEdm.com E-mail Phil or [e-mail]

Table of Contents

Unit 1 Fundamentals of Electrical Discharge Machining
Understanding Electrical Discharge Machining
Electrical Discharge Machining	19	(1)
Various Electric Discharge Machines	20	(1)
Wire EDM	20	(1)
Ram EDM	20	(1)
Small Hole EDM Drilling	21	(1)
Materials That Can Be EDMed	21	(1)
Keeping Abreast With EDM Technology	22	(1)
The Machining Revolution	23	(1)
Understanding Accuracy	24	(1)
Automation and EDM	25	(1)
American Economy and Globalization	26	(3)
Unit 2 Wire EDM
Wire EDM Fundamentals
Revolutionizing Machining	29	(1)
Wire EDM Beginnings	30	(1)
Production Wire EDM	31	(1)
Capabilities of Wire EDM	32	(1)
Wire EDM a Serious Contender With Conventional Machining	32	(1)
New Demands by Design Engineers	33	(1)
Fully Automated Wire EDMs	34	(1)
How Wire EDM Works	35	(2)
The Step by Step EDM Process	37	(2)
Power Supply Generates Volts and Amps	37	(1)
During On Time Controlled Spark Erodes Material	37	(1)
Off Time Allows Fluid to Remove Eroded Particles	38	(1)
Filter Removes Chips While the Cycle is Repeated	38	(1)
Super Precision Band Saw	39	(1)
Independent Four Axis	40	(2)
Understanding Independent Four Axis	42	(1)
Submersible Cutting	43	(1)
Staying Competitive	44	(1)
Profiting With Wire EDM
Users of Wire EDM	45	(1)
Benefits Of Wire EDM	45	(6)
Production Runs	45	(1)
Various Shapes and Sizes	46	(1)
Accuracy and Finishes	46	(1)
Eliminates Extra Machining Processes	46	(1)
Burr Free and Perfectly Straight Machining	47	(1)
Damaged Parts Can Be Repaired with Inserts	47	(1)
Less Need for Skilled Craftspersons	48	(1)
Material Hardness Not a Factor	48	(1)
Computers Can Perform Calculations	48	(1)
Digitizing is Possible	49	(1)
Miniaturization of Parts	50	(1)
Machining With Nozzles Away from Workpiece	50	(1)
Reliable Repeatability	51	(1)
Parts for Wire EDM	51	(7)
Precision Gauges and Templates	51	(1)
Keyways vs. Broaching	52	(1)
Shaft Slots	52	(1)
Collets	52	(1)
Parting Tubes and Shafts	53	(1)
Shaft Pockets	53	(1)
Fabrication of Graphite Electrodes for Ram EDM	53	(1)
Punches and Dies From One Piece of Tool Steel	54	(1)
Progressive Stamping Dies	54	(1)
Short-Run Stampings	55	(1)
Molds	55	(1)
Special and Production Tool Cutters	55	(1)
Difficult-to-Machine Shapes	56	(1)
Other Cost-Reducing Parts	56	(2)
Cutting Shim Stock Absolutely Burr Free	58	(1)
Single Cavity Cut With Wire EDM Into One Side of a Tube	59	(1)
Horizontal Wire EDM	60	(1)
Machining Costs	60	(1)
Proper Procedures for Wire EDM
Starting Methods for Edges and Holes	61	(1)
Three Methods to Pick Up Dimensions	61	(1)
Pick Up Two Edges as in Figure 4:1	61	(1)
Pick Up a Hole as in Figure 4:2	61	(1)
Pick Up an Edge and Holes or Two Holes as in Figure 4:3	62	(1)
Edge Preparation	62	(2)
Square Edges	62	(1)
Machined or Ground	62	(1)
Unfinished Edges	63	(1)
Scale	63	(1)
Pick-Ups	64	(1)
Starter Holes	64	(3)
Automatic Pick-up	64	(1)
Unsquare Holes	65	(1)
Relieved Holes	65	(1)
Smooth Holes	65	(1)
Placement and Location of Starter Holes	66	(1)
Layout	67	(2)
Understanding the Wire EDM Process
Accuracy and Tolerances	69	(1)
Finishes	69	(1)
Wire Path	70	(1)
Wire Kerf	70	(1)
Corners and Radii	71	(1)
Skim Cutting	71	(3)
Barreling Effect and Wire Trail-Off	72	(1)
Metal Movement	73	(1)
Finishes and Accuracy	73	(1)
Carbide	74	(1)
Polycrystalline Diamond	74	(1)
Ceramics	75	(1)
Flushing	75	(1)
Cutting Speed	76	(1)
Impurities	76	(1)
Recast and Heat-Affected Zones	77	(1)
AC Non-Electrolysis Power Supplies	77	(1)
Isolated Pitting	78	(1)
Heat-Treated Steels	79	(1)
Cutting Large Sections	79	(1)
Cutting Sections From a Block	80	(1)
Leaving a Frame	80	(1)
Strength of Frame	81	(1)
Material for Clamping	81	(1)
Understanding the Wire EDM Process	81	(2)
Reducing Wire EDM Costs
Create One Slug	83	(2)
Keeping Flush Nozzles on the Workpiece	85	(1)
Machining After Wire EDM	86	(1)
Cutting Multiple Plates and Sheet Metal Parts	87	(1)
Production Lots	88	(1)
Stipulating Wire Sizes	89	(1)
Pre-Machining Non-Complicated Shapes	90	(1)
Advantages of Wire EDM for Die Making
Tool and Die Making	91	(1)
Old-Fashioned Tool and Die Making	91	(3)
The Revolution	94	(1)
Advantages of Wire EDM Dies	94	(4)
One-Piece Die Sections	94	(1)
Exact Spare Parts	95	(1)
Dowel Holes EDMed	95	(1)
Better Tool Steels	95	(1)
Accuracy	95	(1)
Die Repairs	95	(1)
Fine Textured Finish	96	(1)
Eliminates Distortion	96	(1)
Inserts for High Wear Areas	96	(1)
Smaller Dies	96	(1)
Longer Lasting	96	(1)
Punches and Dies From One Piece of Tool Steel	97	(1)
Cutting Stripper and Die Section Together	97	(1)
Punches	98	(6)
Large Punches	98	(1)
Holding Small Punches	99	(1)
Footed	99	(1)
Shoulder	99	(1)
Keyed In---Toe Clamps	100	(1)
Keyed In---Keyway	100	(1)
Press Fit	101	(1)
Peened Edge	101	(1)
Dowel Pin Reamed	101	(1)
Dowel Pin EDMed	102	(1)
Set Screws	102	(1)
Socket Head Cap Screw	102	(1)
Ball Bearings	103	(1)
Skim Cutting	104	(1)
Die Sections	104	(3)
Heavy Blanking Dies	104	(1)
Avoid Sharp Corners	104	(1)
Heat-Treating	104	(1)
Large Die Sections	105	(1)
Tapers	105	(1)
Taper and Land	105	(1)
Straight Cut and Taper	106	(1)
Wire EDMing One-Piece Stamping Dies
Blanking Die	107	(7)
Desired Stamping	107	(1)
Preparing the Tool Steel Blank	107	(1)
Placement of Starter Hole	108	(1)
Punch Shape is the Desired Stamping	108	(1)
Blank Shape is the Desired Shape	109	(1)
Harden the Tool Steel Blank	110	(1)
Stripper Plate	110	(1)
Punch Holder	110	(1)
Mount Die Blank on Die Set	111	(1)
Mount Punch Holder onto the Die Set	111	(1)
Mount Stripper on Bottom of Die Section	112	(1)
Wire Cut Punch, Die and Stripper	113	(1)
Total Burr-Free One-Piece Blanking Die	114	(1)
Compound Blanking Dies	115	(5)
Desired Stamping	115	(1)
Prepare Tool Steel Blank	115	(1)
Mount Punch Holder	116	(1)
Mount Die Block on Bottom of Die Set	116	(1)
Mount Punch Holder on Top of Die Set	117	(1)
Stripper Plate	117	(1)
Wire EDM Compound Die	117	(1)
Completed Die	118	(1)
Stripper with Springs	118	(1)
Stripper with Knockout	119	(1)
Wave of the Future	120	(3)
Unit 3 Ram EDM
Fundamentals of Ram EDM
Ram EDM Machining	123	(2)
Ram EDM Beginnings	125	(2)
How Ram EDM Works	127	(1)
The Step-by-Step Ram EDM Process	128	(2)
Polarity	130	(1)
No-Wear	130	(1)
Fuzzy Logic	130	(1)
Fumes from Ram EDM	130	(1)
Benefits of Understanding the Process	130	(1)
Profiting With Ram EDM
Uses of Ram EDM	131	(1)
Benefits of Ram EDM	132	(2)
Different Shapes and Sizes	132	(1)
Accuracy and Finishes	133	(1)
Workpiece Hardness Not a Factor	133	(1)
EDMing Threads Into Hardened Parts	133	(1)
Parts for Ram EDM	134	(2)
Molds	134	(1)
Blind Keyways	134	(1)
Internal Splines	135	(1)
Hexes for Special Bolts and Parts	135	(1)
Helical Gear Machining	135	(1)
Micro Machining for Ram EDM	136	(1)
Machining Large Pieces	136	(1)
Materials for Ram EDM	137	(1)
Speeding the Mold Processing	137	(1)
EDMing Carbide	137	(1)
Proper Procedures for Ram EDM	137	(2)
Ram EDM Electrodes and Finishing
Electrodes	139	(9)
Function of the Electrode	139	(1)
Electrode Selection	139	(1)
Type of Electrode Materials	140	(1)
Galvano Process for Metallic Electrodes	141	(1)
Custom Molded Metallic Electrodes	141	(1)
Graphite Electrodes	141	(2)
Electrode Wear	143	(1)
Abrading Graphite Electrodes	144	(2)
Ultrasonic Machining for Graphite Electrodes	146	(1)
Wire EDMing Metallic and Graphite Electrodes	146	(1)
Electrodes and C Axis	147	(1)
Electrode Overcut	147	(1)
Recast and Heat-Affected Zone	148	(1)
Finishing	149	(1)
Mirror Finishing and Diffused Discharge Machining	150	(1)
Micro Machining	151	(4)
Dielectric Oil and Flushing for Ram EDM
Dielectric Oil	155	(1)
Coolant System	156	(1)
Flash Point	156	(1)
Flushing	156	(8)
Proper Flushing	156	(1)
Volume, Not Pressure	156	(1)
Types of Flushing	157	(1)
Pressure Flushing	157	(1)
Pressure Flushing Through the Electrode	157	(1)
Pressure Flushing Through the Workpiece	158	(1)
Suction Flushing	159	(1)
Combined Pressure and Suction Flushing	160	(1)
Jet Flushing	160	(1)
Pulse Flushing	161	(1)
Vertical Flushing	161	(1)
Rotary Flushing	162	(1)
Orbiting Flushing	163	(1)
Filtration System	164	(1)
The Challenge of New Procedures	164	(1)
Reducing Costs for Ram EDM
Preparing Workpieces for Ram EDM	165	(1)
Difference Between Ram and Wire EDM in Reducing Costs	165	(1)
Prolonging Electrode Life With No-Wear EDMing and No Premachining	166	(1)
Electrode and Workpiece Holding Devices	167	(1)
Orbiting	168	(4)
Manual Machines Mounted With Orbiting Devices	172	(1)
Repairing Molds With Microwelding	172	(1)
Abrasive Flow Machining	173	(1)
Automatic Tool Changers	173	(2)
Future of Ram EDM	175	(6)
Unit 4 Small Hole EDM Drilling
Small Hole EDM Drilling
How Small Hole EDM Drilling Works	181	(4)
Dielectric and Flushing Pressure	182	(1)
The Electrode	182	(2)
Electrode Guides	184	(1)
Servo Motors	184	(1)
Metal Disintegrating Machines Compared to Small Hole EDM Drilling	185	(1)
Other Methods to Produce Holes	185	(1)
Disadvantages in Small Hole EDM Drilling	185	(1)
Electrode Wear	185	(1)
Reduced Speed for Large Holes	185	(1)
Blind Holes are Difficult to Control	185	(1)
Advantages in EDM Drilling	186	(1)
Drilling on Curved and Angled Surfaces	186	(1)
Drilling Hardened Materials	186	(1)
Materials That Produce Chips that Cling to Cutters	186	(1)
Drilling Deep Holes	186	(1)
No Hole Deburring	187	(1)
Preventing Broken Drills	187	(1)
Creating Straight Holes	187	(1)
Accuracy of Small Hole EDM Drilling	187	(1)
Versatility of Small Hole EDM Drilling	188	(1)
Conclusion	189	(4)
Unit 5 Questions
Questions
About the Authors	193	(1)
Fundamentals of Electrical Discharge Machining	193	(1)
Wire EDM Fundamentals	194	(1)
Profiting With Wire EDM	195	(1)
Proper Procedures for Wire EDM	196	(1)
Understanding the Wire EDM Process	196	(1)
Reducing Wire EDM Costs	197	(1)
Advantages of Wire EDM for Die Making	198	(1)
Wire EDMing One-Piece Stamping Dies	198	(1)
Fundamentals of Ram EDM	199	(1)
Profiting With Ram EDM	200	(1)
Ram EDM Electrodes and Finishing	200	(1)
Dielectric Oil and Flushing for Ram EDM	201	(1)
Reducing Costs for Ram EDM	202	(1)
Small Hole EDM Drilling	203