20,99 €
Mehr erfahren.
- Herausgeber: John Wiley & Sons
- Kategorie: Bildung
- Sprache: Englisch
Work your way to fabricating success People have been hammering metal into shields, cookware, and ceremonial headdresses for centuries, and fabrication continues to be a popular and growing industry today. Fabricating For Dummies provides you with all the information you need to begin learning about metalworking, or fill any gaps in your existing knowledge in order to advance your career. Simply put, there's little out there for light reading on manufacturing. What's available is often quite expensive, so boring it puts you to sleep, or filled with so much technical gobbledygook that one's eyes glaze over within a few pages. This book offers a much-needed alternative, cutting through the jargon and getting right to the heart of what you need to know to take your fab skills to fabulous new heights. * Get a glimpse of the day in the life of a fab worker * Discover the different alloys, shapes, and sizes of sheet metal * Understand welding and joining processes * Master the use of press brakes, stamping presses, and turret punches Whether you want to get your feet wet with waterjets, laser cutters, or hi-definition plasma cutters, there's something for you inside this hands-on book!
Sie lesen das E-Book in den Legimi-Apps auf:
Seitenzahl: 519
Veröffentlichungsjahr: 2018
Ähnliche
Fabricating For Dummies®
Published by: John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030-5774, www.wiley.com
Copyright © 2018 by John Wiley & Sons, Inc., Hoboken, New Jersey
Published simultaneously in Canada
No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the Publisher. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permissions.
Trademarks: Wiley, For Dummies, the Dummies Man logo, Dummies.com, Making Everything Easier, and related trade dress are trademarks or registered trademarks of John Wiley & Sons, Inc. and may not be used without written permission. All other trademarks are the property of their respective owners. John Wiley & Sons, Inc. is not associated with any product or vendor mentioned in this book.
LIMIT OF LIABILITY/DISCLAIMER OF WARRANTY: THE PUBLISHER AND THE AUTHOR MAKE NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS WORK AND SPECIFICALLY DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE. NO WARRANTY MAY BE CREATED OR EXTENDED BY SALES OR PROMOTIONAL MATERIALS. THE ADVICE AND STRATEGIES CONTAINED HEREIN MAY NOT BE SUITABLE FOR EVERY SITUATION. THIS WORK IS SOLD WITH THE UNDERSTANDING THAT THE PUBLISHER IS NOT ENGAGED IN RENDERING LEGAL, ACCOUNTING, OR OTHER PROFESSIONAL SERVICES. IF PROFESSIONAL ASSISTANCE IS REQUIRED, THE SERVICES OF A COMPETENT PROFESSIONAL PERSON SHOULD BE SOUGHT. NEITHER THE PUBLISHER NOR THE AUTHOR SHALL BE LIABLE FOR DAMAGES ARISING HEREFROM. THE FACT THAT AN ORGANIZATION OR WEBSITE IS REFERRED TO IN THIS WORK AS A CITATION AND/OR A POTENTIAL SOURCE OF FURTHER INFORMATION DOES NOT MEAN THAT THE AUTHOR OR THE PUBLISHER ENDORSES THE INFORMATION THE ORGANIZATION OR WEBSITE MAY PROVIDE OR RECOMMENDATIONS IT MAY MAKE. FURTHER, READERS SHOULD BE AWARE THAT INTERNET WEBSITES LISTED IN THIS WORK MAY HAVE CHANGED OR DISAPPEARED BETWEEN WHEN THIS WORK WAS WRITTEN AND WHEN IT IS READ.
For general information on our other products and services, please contact our Customer Care Department within the U.S. at 877-762-2974, outside the U.S. at 317-572-3993, or fax 317-572-4002. For technical support, please visit https://hub.wiley.com/community/support/dummies.
Wiley publishes in a variety of print and electronic formats and by print-on-demand. Some material included with standard print versions of this book may not be included in e-books or in print-on-demand. If this book refers to media such as a CD or DVD that is not included in the version you purchased, you may download this material at http://booksupport.wiley.com. For more information about Wiley products, visit www.wiley.com.
Library of Congress Control Number: 2018941779
ISBN 978-1-119-47404-3 (pbk); ISBN 978-1-119-47408-1 (ebk); ISBN 978-1-119-47407-4 (ebk)
Fabricating For Dummies®
To view this book's Cheat Sheet, simply go to www.dummies.com and search for “Fabricating For Dummies Cheat Sheet” in the Search box.
Table of Contents
Cover
Introduction
About This Book
Foolish Assumptions
Icons Used in This Book
Beyond the Book
Where to Go from Here
Part 1: Fabricating Truths
Chapter 1: Manipulating Metal
Defining the Processes
Boarding the Bending Express
Peeking at the Neighbors
Reviewing the Rest
Embracing Mechanics
Chapter 2: Looking Back at Fabricating History
Digging for Gold
Pumping Iron
Caring About Fabricating
Chapter 3: Getting to Know Materials
Pondering the Properties
Touching on the Elements
Reconnoitering the Metals Landscape
Alluding to Alloys
Riding the Gravy Train
Peeking Under the Sheets
Part 2: Making Metal Fabulous: The Processes
Chapter 4: Cutting Up
Eating Cake: Power Shears
Lasing About
Firing Up
Beholding the Gantry
Watering Down
Chapter 5: Bending Down
Bending History
“Braking” Up Is Hard to Do
Diving Into Dies
Backgauging the Bends
Crowning Is King
Calculating Conundrums
Chapter 6: Stamping About
Striking Gold
Decompressing Presses
Picking Up the Lingo
Taking Off the Covers
Feeding the Machine
Being Progressive
Chapter 7: Punching Out
Punching Madness
Exploring Operations
Picking Your Station
Getting a Grip
Deciphering Dies
Taking the Combo
Chapter 8: Fabricating Odds and Ends
Working Iron
Rolling ’Round
A Booming Success!
Piping Up
Squeezing in the Rest
Part 3: More Than Machinery: Digging in the Toolbox
Chapter 9: Tooling Up
Digging Metals
Setting Standards
Punching Through
Stamping and Stuff
Donning a Smooth, Slippery Coat
Wrapping Up
Chapter 10: Welding: Putting It All Together
Wondering About Welding
Doing Me a Solid (State)
Firing Up
Arcing Across
Marking the Spot
Getting Gassed Up
Choosing a Good Joint
Learning Safety with Jimmy
Chapter 11: Automating with Robots
Taking Robbie Apart
Leaning on the Tin Man
Laying Down the Law
Gaining Flexibility with an FMS
Watching from Home
Avoiding Bad Actors
Chapter 12: Making Tools and Machining Parts
Touring the Tool and Die Department
Meeting a Few Machine Tools
Staying Sharp with Cutting Tools
Increasing Your Carbon Footprint with EDM
Grinding Is Groovy
Chapter 13: Going Soft(ware)
Unraveling Difficult Acronyms
Figuring Out File Formats
Coloring in the Lines
Modeling Reality
Staring at Clouds
Eliminating Toolroom Chaos
Designing with an Eye to Production
Herding the Shop Floor Cats with MES
Chapter 14: Embracing Quality
Giving a Rip About Quality
Internationalizing Your Standards
Shopping for Tape Measures
Touring the Inspection Room
Letting Machines Do the Measuring
That’s a Wrap
Chapter 15: Making Metal Parts Pretty
Assessing Abrasives
Wheeling About
Talking about Tools
Working ’em Like Dogs
Blasting Away
Finishing Up
Part 4: The Part of Tens
Chapter 16: Ten Techie Things to Know About Fabricating
Joining the Revolution
Cruising the Clouds
Going Green
Getting Lighter
Getting Lost on the Paper Trail
Cutting the Wires
Viewing Machines Virtually
Manufacturing Additively
Embracing Automation
Leaning Out Your Shop
Chapter 17: (Almost) Ten Ways to Be a Better Fabricator
Changing Things Up
Adopting New Technology
Marketing Your Business Vertically
Shortening Setups, Increasing Uptime
Maintaining the Machine (and Tools)
Learning That Manufacturing Is Not a Dirty Word
Becoming Certifiable
Donning Some Cool Safety Shades
Keeping Your House in Order
About the Author
Connect with Dummies
Index
End User License Agreement
Guide
Cover
Table of Contents
Begin Reading
Pages
i
ii
1
2
3
4
5
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
113
114
115
116
117
118
119
120
121
122
123
124
125
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
308
Introduction
Step onto the front porch. Take a look around. There’s the teenager across the street, patiently pounding the quarter panels on her 1969 Volkswagen Beetle into shape, then sanding the metal bare so she can apply a little primer paint. That bug’s going to be a beauty when she’s done.
The kids two houses over are constructing a treehouse, nailing and screwing together the stray bits of sheet metal and scrap lumber found at the housing development five blocks down. Their arboreal creation is sure to block what’s left of your sunset views. Have to talk to their dad about that.
And then there’s the bridge project on the interstate. It’s been going on all summer — the endless, inexplicable welding and cutting and pouring that promises to lop fifteen minutes off your commute when finished.
These are a few of the everyday examples of fabricating. It’s going on all the time, all around us, and it’s an important part of our lives. Without fabricating, there’d be no central air conditioning in our homes, no kitchen appliances, no car in the garage. None of that would really matter though, because modern day conveniences like gas stations and food processing plants wouldn’t exist, let alone windows and doors on the house.
You might be able to catch a chicken for dinner and club it with a rock, but you’d need a stone knife to prepare the thing before you could huddle around the fire with the family to eat it. Strip malls and skyscrapers, farm tractors and fryer baskets, prescription drugs and polyester ski jackets … fabricating makes it all possible.
Even the paper airplanes you made as a kid (and might still be making). That’s fabricating (albeit of paper rather than metal). Sewn a dress or made an Iron Man–like suit of armor? Yep, both fabricating. Spent all weekend assembling and then reassembling a metal shed because you didn’t read the instructions the first time? That is an example of fabricating followed by reworking, an unpopular term in any fab shop.
Still, what exactly does “fabricate” mean? A quick Google search says it’s a transitive verb (I shouldn’t have slept through English class, as I’m still unsure about the transitive part) used to describe the following acts:
Inventing or concocting (something), typically with deceitful intent
Constructing or manufacturing (something, especially an industrial product), especially from prepared components
Well, the first definition doesn’t apply at all to the fabricating I’m talking about. Sorry, Merriam-Webster. The only deceitful intent you might find in a fab shop is someone sneaking out a few minutes early on Friday for happy hour with his or her coworkers. As for the second description, the fabricating I discuss in this book is more about actually making those “prepared components” than it is about bolting or gluing or welding them together (although assembly is certainly a familiar process at most fab shops).
Granted, it’s a broad term. Civic construction projects, autobody repair, bridge building, and pipeline laying — technically speaking, these fall into the general category called fabricating, and are performed by companies with fabricating as part of their business name, but much of that work falls outside the context of this book.
For the purposes of this book, “fabricating” and “fabrication” and sometimes just plain old “fab” are meant to describe that subset of metalworking concerned with forming, bending, cutting, drilling, finishing, and otherwise manipulating sheets of metal (tubes and pipes pop up occasionally as well, as does welding and even machining).
Whether you’re looking for a new profession (one with plenty of eager employers) or just want to know how the heck refrigerators and jungle gyms are made, this book is for you. You’ll find out about the machines that shape metal, the tools that slice and form it, the robots that lift it, the software that figures out the best way to process it, along with a few mandatory historical tidbits you can share with your friends in your Thursday night bowling league. So get reading.
About This Book
To borrow a cliché, fabricating has a lot of moving pieces. That’s why Fabricating For Dummies is broken up into bite-sized ones. Part 1 provides a high-level overview of the different fabricating processes, the metals used in those processes, along with a little bit of metalworking history (but don’t let that scare you). Part 2 dives deeper into the specifics of punch presses, stampers, and other fabricating equipment, while Part 3 talks about auxiliary topics such as automation, welding, and software. And of course, no For Dummies book would be complete without a Part of Tens, which in this case offers advice and information on a variety of manufacturing areas.
All in all, Fabricating For Dummies covers half a dozen or so distinct metalworking processes, along with measuring, painting, grinding, toolmaking, and a little machine-tool programming. There’s even a little history inside, but you can skip those parts if you really don’t care about the accomplishments of others.
I hope that’s not true, though, because where would we be without Abraham Lincoln, John F. Kennedy, Alfred E. Neuman (What? Me worry?), and all the other important people without whom modern society wouldn’t exist. The same goes for the men and women who work in our manufacturing plants every day, who bend, shape, cut, and assemble the products that make our lives safe and comfortable. You guys and gals are the best.
Foolish Assumptions
This book assumes you’re interested in fabricating and metalworking. There are no prerequisite skills needed, such as being able to build a shed or having once straightened a dented fender on your lime green Kia Soul, to understand the concepts discussed herein. If you have been yelled at by your mom for using her manicure scissors to trim the dog’s nails, you already have a leg up on fabricating (the first machine I ever ran was a shear, a 12-foot long version of mom’s clippers). If you installed a garage door or cut and soldered some new pipes in the bathroom, better yet. Oh, and you should know the difference between metal and other everyday materials like plastic and wood (metal is the hard, shiny stuff).
And since the majority of all machines these days are controlled by computers, you hopefully know what one is, and understand that they are actually in charge of everything around us and will one day enslave all humanity. But that’s years in the future. For now, knowing what I mean when I use geeky terms like “network” and “software” will see you through the book just fine.
Icons Used in This Book
My dad’s full of good advice. Don’t stand up in a canoe. Drink more water. If you can do something in less than five minutes, do it now. A fool who can keep his mouth shut is counted amongst the wise. You can outrun the cop, but not the radio (actually, I found this one out on my own). I can’t compete with Dad’s nine decades of wisdom, but once in a while I pull an anecdotal rabbit out of my hat like, “Write it down because you won’t remember it in the morning.” Keep an eye out for the Tip icon for more of these gems.
Manufacturing technology continues to become easier for us simple humans to master, but it’s still pretty darn technical at times. For example, did you know that fiber lasers work best when nitrogen is used as an assist gas, or that the tools used in turret punches should be demagnetized before use? See? That’s what I mean. It’s important information. That’s why there are all these Technical Stuff icons scattered throughout the book.
They say elephants never forget. If I were an elephant, all the other elephants in the herd would make fun of me, because I can’t remember Jack (or Jill, for that matter). If you, too, suffer from CRS (can’t remember … stuff), feel free to lean on the Remember icons you’ll find in the coming chapters (assuming I don’t forget to put them in).
Machines have moving parts, often moving up and down faster than a seamstress’s needle. Visit the Old Fabricators’ Retirement Villa and you’re sure to see plenty of truncated thumbs and more eye patches than at a pirate convention. Fortunately, fabricating has become far safer over the years, but that doesn’t mean you should be careless. Watch for the Warning icons if you want to retire with all your digits.
Stop for red lights. Tip the waiters if you want good service next time. Let sleeping dogs lie (that might have been one of my dad’s tidbits). Whatever the case, these are a few examples of life’s important details, some of which are explained to us by friends and family, while others are learned through trial and error. In this book, be sure to read the information in Important Details if you want to avoid finding things out the hard way.
Beyond the Book
Can’t get enough of fabricating? I get it, really, which is why this book comes with a free access-anywhere Cheat Sheet that offers additional tips on laser cutting, press brakes, welding, and robots, and how to get to the Old Fabricators’ Retirement Villa safely. To get your very own copy of this Cheat Sheet (suitable for framing), head on over to www.dummies.com and type Fabricating For Dummies Cheat Sheet in the Search box.
Where to Go from Here
If you haven’t yet figured out what you want to be when you grow up (don’t worry, it took me a few decades), then this book might be the turning point. You can forget about majoring in history. Set aside your plans to own a floral shop. Mrs. Carnahan, thanks for driving the school bus, but fabricating might have been a more rewarding career choice. The pay is better and no one puts gum on your seat.
You can start by checking out the local vocational school. If your instructor’s an old-timer, you might learn about manual sheet-metal layout using Dykem (a nice-smelling though noxious blue dye), a scribe, and a marking punch, but once that now largely unnecessary lesson is behind you, you can move beyond the basics to stuff like bending allowances and how to set up a turret punch.
Check out the Fabricators & Manufacturers Association (www.fmanet.org) website for participating trade and technical schools, or if you’re a veteran, cruise over to Manufacturing Day (www.mfgday.com/blog/future-veterans-manufacturing) or give Workshops for Warriors in San Diego a call (https://workshopsforwarriors.org). They have some awesome programs available for transitioning service members, and you can spend your weekends learning how to ride a boogie board and find out when it’s appropriate to say “gnarly, dude.”
And if you’re content with your current job, congratulations. Fabricating is still a nifty hobby, and if you want to learn how to bend up a galvanized steel doghouse for your prize-winning Pekingese, what better way to get started than by reading this book? Either way, it’s time to march up to the counter, hand over your hard-earned cash to buy this book (or enter your credit card number on whatever bookseller’s website you’re currently surfing) and read it from start to finish. Get going.
Part 1
Fabricating Truths
IN THIS PART …
Buzz the tower of common fabricating technologies. Don’t worry; it’s perfectly safe.
Learn the importance fabricating has to your everyday life and why there’d be no cars, appliances, or lawn furniture without it.
Cruise through a short fabricating history lesson and learn interesting facts about a bunch of ingenious, mechanically-minded people.
Explore metal sheet, plate, and tubing, gaining great appreciation for hardware stores and metal supermarkets along the way.
Chapter 1
Manipulating Metal
IN THIS CHAPTER
Introducing basic metalworking processes
Understanding the difference between bending and forming
Comparing fabrication to other manufacturing processes
Taking apart the machine for a peek inside
It is not knowledge, but the act of learning, not possession but the act of getting there, which grants the greatest enjoyment.
— CARL FRIEDRICH GAUSS
In 1987, ex-Beatle George Harrison released the hit song, “When We Was Fab,” in which he lamented the loss of his youth and the subsequent breakup of the original boy band from Liverpool. In spite of his poor grammar (or perhaps in part because of it), Harrison’s tune caught on. Although it might sound silly, I can’t listen to the late musician’s hit single without thinking about the fabrication, or fab, shop where I once worked, the sounds of stamping presses and laser cutters rattling about behind my ears. Am I crazy, or is that a sign of too many years making parts?
It’s certainly not the latter. Metalworking is an awesomely cool profession (albeit one that’s a bit noisy), and I wouldn’t trade the memories of those sounds and smells for anything. Walk into any fab shop and you’ll immediately know what I’m talking about — the boom …boom … boom of the heavy stampers reverberating through the floor like the footsteps of a not-so-distant giant.
From the other side of the factory comes the machine-gun sound of the turret presses, the crackle of the welders, and the hiss of lasers and waterjets and high-density (also known as high-definition) plasma cutting machines patiently slicing through steel. It’s an awesome experience. Yes, it can be a loud place (be sure to wear your hearing protection), but there are some wondrous things going on here; metal is being shaped and stamped and sliced and bent into parts that are used all over the world and held to tolerances finer than the thickness of a human hair.
Defining the Processes
Even more so than those shops that cut metal on lathes and machining centers each day (that is, machine shops), every fabrication shop is different. Where some specialize in welding large metal structures like electrical distribution towers and railroad trestles, others cater to customers looking for hydro-formed parts or millions upon millions of stamped-metal widgets.
The term fabricating covers a diverse set of technologies, some performed on generic machine tools that might accommodate dozens of distinct processes, others on specialty equipment that does only one thing. I dive more deeply into the more common of these processes in Part 2, but for now, let’s take a 30,000-foot view of all that it might mean to be a fabricator, starting with cutting, a generic term that includes cutting metal with a stream of high-pressure water, a high-powered laser, or a jet of super-hot plasma, and is one of the primary operations performed on sheet metal, plate stock, angles and shapes, and billets.
Cutting up
Look up the word “cut” in the dictionary and you’ll see it described as “using a sharp instrument to sever, slice, or chop” something, as in “I cut my big toe on the doorjamb last night.” Ouch. When it comes to sheet metal, however, cutting generally means fracturing the material — no sharp edges are needed, at least not like the tip of a kitchen paring knife.
Punching and shearing operations usually require two precision-ground edges to be slid past one another, often at a high rate of speed but not always so. As they pass, the material trapped between these opposing forces deforms momentarily and then fractures, whereupon a section of raw material literally breaks away from the sheet, plate, or angle from which the workpiece is being made. Examples include the punch and die set used to punch out millions of shiny new pennies, or a huge scissors-like machine tool known as a shear (something I slice into shortly).
To be completely accurate, much of the “cutting” done in the fabricating world is actually a shearing operation of some sort, although that’s not to say you can’t cut a piece of material with a bandsaw — it’s done all the time but is generally reserved for materials too thick to shear using conventional means, or by shops that don’t have a heavy-tonnage shear.
Even though the mechanisms are fundamentally different, the term cutting has also come to encompass newer technologies such as abrasive waterjet machines and laser cutters, both of which are giving their centuries-old shearing counterparts a run for their money (see Figure 1-1).
Courtesy: WARDJet, Inc.
FIGURE 1-1: Abrasive waterjet machines can quickly and cleanly cut virtually any material in any thickness, from the hardest steel to the most friable stone.
Shearing specifics
My wife owns a set of heavy-duty kitchen shears. She hides them in the drawer behind the Ziploc bags, and occasionally inside her nightstand drawer. I love those shears, and even though she yells at me for doing it, I use them to cut everything. Aluminum foil, cardboard, rope, that nearly-impossible-to-open plastic packaging that once contained my latest Captain America figurine — you name it, they cut it.
But shears do far more than create domestic disputes in the kitchen. Industrial shears are just as important to those who process sheet metal for a living. They function in much the same manner as their smaller household counterparts, by passing a blade of hardened steel past a stationary but similarly shaped blade below. This fractures the metal, and if all has been set up properly, will leave a straight, clean edge with minimal burr. (Burrs are those annoying, ragged, and often sharp edges that can send the incautious among us to the emergency room for stitches.)
Suppose you want to make a replacement electronics cabinet for your vintage Elvis Presley pinball machine. You might start with a 4-x-8-foot sheet of aluminum, shear off a piece to match the cabinet’s “unfolded” dimensions, notch out the corners (perhaps using a punch press), bend it up on a press brake, and then spot weld the corners together. The King is back in business. (I talk more about these operations in Part 2.)
Slitting success
Pretend it’s your favorite nephew’s birthday and you want to wrap the For Dummies book you’re giving to him as a gift. The roll of paper is 36 inches across — far too wide for that yellow-bound work of art — so you decide to slice the paper in half lengthwise. If the gift wrap were made of steel, you would have just performed a slitting operation, and it’s the first step in the process that turns coils of steel perhaps six feet wide, thousands of feet long, and weighing tens of thousands of pounds into more manageable pieces of raw material (check out Figure 1-2).
mady70/Shutterstock
FIGURE 1-2: Every day, metal coils weighing more than a school bus are slit, sheared, stamped, and formed into millions of different parts.
Slitting is a type of shearing operation, except it’s usually done continuously, lengthwise down the coil. A single coil might be unwound, slit into whatever widths are needed, then rewound again on the opposite side of the slitter in one continuous process. It could also be used to feed a stamping line — flattened and sheared into short lengths to make sheet stock for use on a turret punch or laser cutter — or sent to a blanking line as the first step in the production of the door panel for the new sports car you’re planning to buy next year.
Punching out
The mechanics of punching are much like those of shearing in that the metal is first deformed and then fractured in rapid succession as the tool moves past. But where shearing uses a set of opposing blade-like tools to get the job done, punching relies on a punch and die set (hence the name) that fit together precisely, one within the other (Figure 1-3 shows a photo of one such tool).
Courtesy: Wilson Tool International
FIGURE 1-3: As the name implies, these multitools contain multiple punch and die sets, which can be indexed to whichever tool is needed. They are a favorite of turret punch-press operators who’ve run out of tool stations.
Suppose you want to make a series of Mickey Mouse–shaped holes in a sheet of aluminum. (I’m unsure why you would want to do this, but you get the idea.) Accomplishing this task would require a punch made of hardened tool steel or tungsten carbide (sometimes simply called “carbide”), which in all likelihood was cut using a wire electrical discharge machining (WEDM) machine to resemble everyone’s favorite rodent. (I talk about EDM and other toolmaking processes in Chapter 12.)
The punch will be mounted in the top station of a punch press or possibly in the upper half of a stamping die. In either case, a mating female die must be positioned directly below it. Some small amount of clearance (less than a hair’s width, most likely) between the punch and die is required for machine misalignment and to allow the slug to pass through, with thicker materials requiring commensurately more clearance than when punching thin materials. Slide the material between the two halves of the mating tools, give the punch a whack, and there’s Mickey.
Perforating
Here’s another punching example. Most of us who live in the desert Southwest have a security screen door on the front of our house to allow fresh air in while keeping critters such as coyotes and javelinas (which look like wild pigs) out. These doors are made of perforated metal — it resembles a window screen but is thicker and strong enough to withstand inquisitive noses. Perforated metal is also used for washer and dryer drums, screens for separating materials in food processing, and as decorative panels in architecture.
Perforated metal is produced in a variety of ways. The most common employs a device that looks similar to a rolling pin that has a series of sharp needle-like punches around its circumference. As this “perforation roller” rolls over the metal, it continuously punches round, square, or whatever-shape holes are desired along its surface. Now take this concept one step further. Rather than a cylindrical roller, it’s quite feasible to produce the holes en masse via a metal plate that looks like a bed of nails and a matching die set. Just give the sheet a good whack as it passes beneath and thousands of perforations can be made in one shot.
Expanded metal is a close cousin to perforated metal. Like chicken wire on steroids, it’s great stuff for non-slip surfaces on industrial walkways and running boards on monster trucks. And to borrow another example from the desert Southwest, expanded metal lath is commonly applied to the outside of houses before slathering them with stucco. Rather than simply punching holes and diamond shapes as with perforated metal, however, expanded metal is made by simultaneously stretching the metal while punching small slits into it, much like the process we once used to make paper snowflakes as children. (It’s perfectly okay if you still do so.)
Blanking
As I mention a few pages back, sheet metal starts out as humungous coils of material that are delivered from the mill to a metal processor. These are then sliced into narrower coils or sheared and flattened into manageable pieces approximately the size of the plywood sheets you’ve probably purchased at one time or another from the local lumber yard.
In either case, the sheet stock is often “blanked” into a variety of shapes that are sent on to secondary processes. For high-volume applications such as automotive door panels, this is usually accomplished using a punch and die on a dedicated blanking line. A punch of the desired shape is forced through the sheet and into a mating die. This shears the door panel out of the sheet, causing it to fall through.
What’s the difference between a blanking operation and, say, cutting an oblong-shaped window or punching a hole in a workpiece? Easy. With blanking, the piece that falls through the sheet is the workpiece, whereas in a normal piercing or punching operation, that leftover chunk of material is scrap.
For higher-volume shops, blanking is often done with a punch and die set, but shops could also use a laser, waterjet, or shear to knock out whatever shape is needed for the forming press or press brake. The decision as to which is most cost-effective largely depends on job quantity, edge quality, material thickness and type of material, and which machine is most readily available.
Boarding the Bending Express
Virtually all sheet metal is bent or formed into some sort of shape eventually. If not, it would just lie there being flat for its entire life, good for little more than a gasket or shim. Boring, right? Most of the time, bending operations belong to the press-brake department, but that doesn’t mean you can’t bend a bracket with a die set in a stamping press, or fold a short, shallow louver using a special tool in a turret punch press. Fabricators are clever people, and they are constantly coming up with ways to make their equipment work for them.
Putting on the brakes
Bend a piece of metal too far or too fast and it will fracture, which is the same mechanism involved in shearing. But by controlling it carefully (and by selecting metal that boasts sufficient plasticity), precise, high-quality bends can be made in a variety of metals.
I get into the nitty-gritty details of press brakes in Chapter 5, but for now, you can think of one as a big paper airplane folding mechanism with a V-shaped (usually) punch on the upper side of the press and a mating female die on the bottom. Squeeze a sheet of metal between the two halves and a variety of shapes can be formed.
There’s way more to the story than this. Accurate tonnage and bend calculations, the types of tooling used, blank size, corner radii and part dimensions, and the order in which bends are made all play a role in the success of any bending operation. Check out Figure 1-4 for an in-process photo.
Courtesy: LVD Strippit
FIGURE 1-4: Bending complex parts like this is all in a day’s work for a modern computer numerical control (CNC) press brake.
Forming opinions
Step out to the garage for a moment to groove on the sleek lines of your 1991 Yugo GV. The quarter panels, hood, roof, doors, and even some parts of the frame were made on a stamping press larger than a studio apartment. (Sadly, the Serbian plant that once made the Yugo was destroyed by NATO bombs in 1999.) Heavy stampers work much like press brakes, except that rather than bending up a box one edge at a time, the heavy stamper would form the entire box in one shot: BOOM!
Just kidding — it would be impractical to form a box shape in this manner, as the corners are too sharp and the metal would buckle. But heavy stampers can form very complex shapes. Just drive down the street and admire the far sexier curves of cars thirty years newer than the boxy, Yugoslavian automotive marvel tucked away in your garage.
Thinking progressively
Stamping presses go up and down. Build a die set that can perform multiple operations “per stroke” and you have the ability to make some pretty complex stuff and do so very quickly. Consider a tiny electrical connector or a clamp for a radiator hose. A progressive die might perform a dozen discrete operations on parts like these. Punch a hole, bend a tab, cut a window, form a flange. With each stroke of the press, the part advances to the next station until the final step: separation from the strip of leftover material, known as a remnant.
Progressive dies are expensive, and they might take months to test and develop. Most are designed to crank out tens of thousands of parts per minute — a high-speed stamping press can exceed 2,000 strokes per minute, dropping one complete part per stroke (that’s 120,000 pieces each hour). Check out Chapter 6 if you want to find out lots more about stamping technology; until then, you’ll have to settle for Figure 1-5, which shows a sideways view of a progressive die mounted in a stamping press.
JETSADA POSRI/Shutterstock
FIGURE 1-5: Progressive dies perform multiple successive stamping operations with each stroke of the ram.
Spinning in circles
Here’s another type of forming, one far different and much more limited than a stamping press, but capable of some whiz-bang shapes nonetheless. Ever seen the nose cone on a rocket? How about a stainless-steel bowl big enough for the massive amount of potato salad you’re being forced to make for the upcoming family reunion? These and other thin, dome-shaped parts are produced by spinning, which, like other forming processes, relies on the ductility of many metals for shaping complex parts to close tolerances. (I discuss ductility and other metallurgical properties in Chapter 3.)
A spinning machine is like a big lathe without the metal cutting tool. The operator starts by clamping a mandrel that’s shaped like the inside of the nose cone or salad bowl to the lathe spindle. A flat disk of material is then pinched between the end of the mandrel and a pressure pad. The spindle starts up and a “spoon” made of hardened steel or brass is used to apply pressure to the metal, which gradually bends and takes the shape of the mandrel beneath.
Peeking at the Neighbors
These were but a few examples of all that fabricating makes possible. But what is this thing called fabricating? How does it work, and what makes it different from machining, injection molding, three-dimensional (3D) printing, and all the other manufacturing technologies in existence today? Read the rest of the book if you want a more complete answer, but here’s a sneak peek at what goes on beyond the walls of the fabrication department every day in shops near and far.
MACHINING VERSUS FABRICATING
You machinists who are secretly reading this book hoping that none of your coworkers catch you studying the fabricating dark side might be thinking, “Can’t some of this stuff be done with drills and milling cutters?” The answer is yes, it certainly can, but there’s one thing to consider: Sheet metal is hard to hold onto. This isn’t a problem when you’re stamping a hole on a punch press or laser-cutting a window because those cutting forces push down on the sheet (or in the case of lasers, create virtually no cutting forces at all). If you were to try that on a milling machine, the bit would grab and lift the material, quite possibly turning it into a razor-sharp windmill. A vacuum chuck (or even a piece of double-backed tape) is able to grip thin, flat materials, but this is far less practical (and much slower) than knocking those shapes out on a press.
Touring the machine shop
Machining is an important part of fabricating, which is why I cover it more deeply in Chapter 12. For now, though, you should know that without machining, none of the punches, dies, and other tooling needed to fabricate parts could be made, never mind the fabricating machinery itself.
It’s also a subtractive metalworking process (as opposed to an additive one, something I talk about a little further along in this chapter). It uses chunks of very hard metal such as tungsten carbide or high-speed steel (which are also used in fabricating) that have been precision-ground into drills, end mills, reamers, and dozens of other types of cutting tools.
Cutting tools are dragged across or through a bar or billet of material to accurately remove small bits of metal from it. These are called chips, and if you get one in your eye or wrapped around a finger, you’ll have an opportunity to chat all about machining with a doctor at the emergency room as he administers first aid.
Depending on the type of machine tool you stand in front of each day, you might perform any or all of these machining operations in order to complete a given workpiece:
Drilling
EDM
Grinding
Milling
Sawing
Threading
Turning
I admit, those are some pretty broad categories. Turning, for example, comprises dozens of unique operations, including profiling, grooving, boring, drilling, cutoff, and more. If you want to learn more about these and other machining processes and technologies, you can check out my book, Machining For Dummies, where, as you might have guessed, I go into the meat and potatoes of all things machining.
Wake up, it’s time to get vertical
For now, though, let’s look at some of the other cool things you can do as a manufacturing person. Some of them have literally nothing to do with fabricating, but as my Uncle Ted once told me, “Knowledge is power, young man.” He then punched me in the shoulder and told me to go get him a beer.
The old coot’s wise words notwithstanding, you’ll find that fabricating shops tend to be more “vertical” than most manufacturers, which is an industry term that means these shops try to do whatever is needed to complete a part or assembly. This might mean they’re cheap and don’t wish to share any work with the paint shop or welding business down the street, but it could also mean they’re smart.
Want to get ahead as a fab shop? Vertically-oriented manufacturers have more control over their products (which usually translates into better quality), greater flexibility, shorter lead times, and — probably — higher profit margins as a result. In the fabricating world, this means you’ll do the usual bending, shearing, and forming, but are also happy to paint, powder coat, weld, assemble, and machine parts (all of which are discussed later in this book).
Reviewing the Rest
Here are a few additional metalworking (and plastic working) processes. Some are as old as Roman times; others were invented around the time Ronald Reagan was huddled with his advisors, dreaming up trickle-down economics. Again, these are typically not performed at most “fabricating” companies, but if you’re power-hungry and want to be the Amazon.com of manufacturing, you’ll embrace these processes with equal aplomb.
Thinking additively
You might know it as 3D printing. This process works by electronically slicing a 3D CAD (computer-aided design) model into paper-thin layers and then growing the part from the bottom up (although some newer printers start at the top). There’s no material waste, part accuracy competes with other manufacturing processes, and 3D printing is widely used to make a wide array of prototype and low-volume production parts. Nine distinct 3D printing technologies exist, with these three leading the pack:
SLA (stereolithography):
Developed in the early 1980s, SLA is the grandfather of commercial 3D printing. It uses a UV laser beam to cure layers of photosensitive liquid resin. As each layer is completed, fresh material is scraped over the top of the developing workpiece and the process begins again.
SLS (selective laser sintering):
SLS is a powder bed fusion technology that uses a laser to fuse layers of plastic or metal (this is often referred to as
selective laser melting
or SLM) contained in a heated powder bed. As with SLA, a blade or roller spreads material over the top of the workpiece after the completion of each layer.
FDM (fused deposition modeling):
Similar in operation to a hot glue gun, FDM deposits molten material one layer at a time, tracing the outline and then the interior of each layer until complete. It is one of the few additive manufacturing technologies that allows multiple materials to be used in a single “build.”
Additive manufacturing offers many benefits. Some use materials with physical properties equivalent to their forged or cast counterparts. Virtually any shape can be printed, even those (or rather, especially those) previously considered un-manufacturable — or which at least required the assembly of many parts.
3D printing is, however, relatively slow, and a part the size of a breadbox might take days to manufacture. There are several new technologies coming online right now that claim to drastically increase production speeds. If successful, these new technologies promise to change the landscape of manufacturing substantially, especially in the machining world. Feel free to skip forward to Chapter 16 for some additional details on this revolutionary technology.
Casting away
If you were lucky enough to take industrial arts (also called “shop” class) in high school, you might have made a pair of cast aluminum candleholders to give to Mom for her birthday. Casting is a lot like plastic-injection molding, used to make everything from Tupperware to toothbrushes, except that casting denotes metal, while molding refers to plastic (unless you’re talking about metal-injection molding, which is another story entirely).
The casting method we former industrial artists are most familiar with is called sand casting. It works by pouring molten metal into a mold formed by compacting fine, powdery sand around a master part (the pattern) that is held between the two halves of the mold (the cope and drag). The mold is gently separated and the pattern(s) removed, then hot metal is poured into the sprue (a hole in the top of the mold). Once cool, the mold separates, hot, smelly sand goes flying all over the place, and presto! Mom gets a shiny new pair of candlestick holders that she’ll treasure forever.
There’s also investment casting. This uses a wax or foam pattern that is melted or “lost” during the casting process (which is why it’s also called lost wax casting). Many aerospace and similar high-tech components are made using investment castings, thanks to its ability to create accurate parts with fine features.
Die casting uses a set of hardened metal dies, into which molten metal is forced at high pressure. If you played with Matchbox cars as a kid (or still do today), you are familiar with die-cast parts. It’s also used to make a variety of high-volume automotive and consumer products, including the transmission body in your car, the faucets in your bathroom, and the compressor housing in your refrigerator.
Forging partnerships
Forging is as old as metalworking itself. Start with a chunk of steel (or bronze or iron), stick it in a fire until red hot, and start whacking. If you’re strong enough and patient enough, you might make a nifty set of horseshoes for old Bess or some armor to defend yourself against marauding Huns. And as I mention in Chapter 2, repeatedly pounding some metals makes them tougher and more wear resistant (see Figure 1-6).
Ermolaev Alexander/Shutterstock
FIGURE 1-6: Blacksmithing was among the first metalworking processes and was used to not only shape metals but also make them stronger.
But because people’s arms inevitably get tired, some clever blacksmith eliminated the grunt work of forging by inventing a machine called a drop hammer. And because pounding metal with the consistency of super-taffy into an accurate shape is quite challenging, some equally clever blacksmith invented the forging die.
Like the molds used to make castings, these contain the inverse shape of whatever wrench handle, cabinet hardware, gear blank, or other mechanical component is desired. Simply set the hot metal blank into the die, spank it once or maybe a dozen times (depending on the type of forging process, the part geometry, and the metal used), and out comes a part ready for final machining.
Honorable mentions
These brief descriptions pay short shrift to the complexity and capabilities of casting, forging, and their far more modern counterpart, 3D printing. Nor do the preceding sections mention any of the other important metalworking processes such as powder metallurgy, swaging, explosive forming (yes, they really do that), ultrasonic machining, photochemical milling, and others.
Some of these fall under the umbrella term fabricating, which is why I revisit many of them in later chapters — punch presses, for example, are discussed in Chapter 7. But since this book is mostly about sheet-metal fabrication techniques with some segues into welding, plate processing, and automation, I’d best avoid my editor’s wrath and stick to those topics, saving the rest for another time.
Embracing Mechanics
Whether a punch press, laser cutter, swaging machine, or ironworker (a multi-purpose machine tool that I explain in Chapter 8), all fabricating machinery shares some basic mechanical similarities. Each machine has a frame made of metal (usually cast iron). Each has bearings and sliding surfaces. Most are driven by computers and servo systems, known as computer numerical control (CNC). Here are a few of the most important components along with some brief descriptions of each to mentally arm you for the chapters to come:
Bearing witness
Without bearings, your car wouldn’t roll. Fidget spinners wouldn’t spin, and the garage door would be permanently shut. That’s because bearings allow surfaces to slide freely against one another (see Figure 1-7). Most of the bearings you find in such everyday devices are donut-shaped, with inner and outer races and metal balls or needles contained between the two. Some bearings are flat and use a similar arrangement of balls or needles (the drawers in a toolbox are one example). And some bearings are actually known as “ways,” with two precision-ground metal surfaces separated by a thin film of oil.
AnnaElizabeth Photography/Shutterstock
FIGURE 1-7: Whether round, flat, or angular, bearings allow machinery to operate smoothly and accurately.
It’s this last approach that is used in many machine tools. So-called “box ways” are able to support massive loads while still maintaining extreme precision and have long been used in stamping presses, shears, and press brakes. And linear guideways, which contain specially-shaped rails and ball-filled “trucks” that ride atop them, provide smooth, accurate motion and excellent load-bearing properties even at very high rates of speed. This makes them a favorite in machine tools that move very quickly, such as laser cutters and turret presses.
Motoring about
At the risk of leaning on the automobile metaphor one too many times, your car would do nothing but take up space in the driveway without a motor. But unless you own a Tesla, the motor in your car is completely unlike the ones used to power virtually all machine tools. Electric motors turn turrets, drive rams, power hydraulic pumps, and are what make the flying optics in laser cutters fly with purpose-filled abandon.
Most of today’s CNC machines use highly efficient alternating current (AC) motors that take orders from onboard servo systems, which are in turn controlled by the machine’s computer program. They make press brakes go up and down and turret punches move side to side and in and out, and they can do so accurately, even when bending or punching a chunk of steel thicker than your hand.
Controlling motion
The servomotors described in the previous section require a way to convert their rotary motion into the linear motion needed to actually perform work. In most cases, this means attaching a “ball screw” to one end of the motor. A ball screw looks like a super-long bolt with roundish threads that fit inside a ball-filled nut that rides up and down the length of the ball screw as it rotates. Because this may be tough to visualize, take a peek at Figure 1-8 to see what a ball screw looks like.
v1875/Shutterstock
FIGURE 1-8: Ball screws are responsible for quickly and accurately transmitting motion in CNC machine tools.
Some newer, very high-speed machine tools have linear motors. These are essentially “flattened” electric motors that eliminate the need for ball screws entirely. They can accelerate and decelerate very quickly and achieve speeds far greater than what’s possible with traditional ball screw–equipped machines. If you’ve ridden the rollercoaster, Superman: The Escape at Six Flags Magic Mountain in Valencia, California (or are a fighter pilot on an aircraft carrier), you’re familiar with the power of linear motors.
Mulling over the miscellany
The list of components needed to build a precision CNC machine tool costing more than a three-bedroom house in the suburbs is far longer than the meager list discussed in the previous paragraphs. Aside from the ball screws or linear motors just described, pulleys and gears and crankshafts are also used to transmit motion. Sheet-metal enclosures and safety glass are needed to protect human operators from injury. Lasers are used to cut metal, but they’re also an important part of operator safety, shutting off the machine when unwary or overconfident hands are placed too close to moving parts by intercepting a ray of light paired with a receiver. Then there are shafts, seals and O-rings, pins and washers, and of course, the nuts and bolts that hold the thing together. To say it’s complex is like saying Bill Gates is moderately wealthy.
Chapter 2
Looking Back at Fabricating History
IN THIS CHAPTER
Hammering metal into headdresses
Excavating the elements
Blacksmithing — it’s not just for horseshoes
Hypothesizing about hardware
Perusing metalworking processes
… and they shall beat their swords into ploughshares, and their spears into pruning hooks: nation shall not lift up sword against nation, neither shall they learn war any more.
— BOOK OF ISAIAH
The Soviet Union once presented the United Nations with a bronze statue of a man pounding on a sword with a hammer. At its base reads a snippet of the preceding quote, signifying our desire as human beings to put an end to war forever. It was a grand gesture and remains one of the more treasured items in the United Nations’ art collection. The year was 1959.
But the artist who constructed it, Ukrainian-born Yevgeny Vuchetich, knew a heck of a lot more about shaping metal than he did about human nature. Just three years later and a few days after I was born, Soviet leadership positioned nuclear weapons in Cuba capable of burning their bronze gift and everything else in New York City to the ground. Those two weeks in October nearly ended everything.
Yet humanity is a slow learner. The people responsible for that global near-miss are long gone, but the ones who’ve taken their place seem to have learned not a whit from their predecessors’ mistakes. I guess The Who’s Peter Townshend was right when he sang, “Meet the new boss. Same as the old boss.” Ah well, whatever the fate of the human race, what’s important right now is that I’m still here, as are you, so let’s continue to talk about that old Ukrainian sculptor’s craft: fabricating.
Digging for Gold
It’s a noble trade. Metal fabricating predates that Old Testament notion of swords and ploughshares by a fair spell. No one knows exactly when, but most historians agree that people started using rocks to pound metal into tools and ornaments many thousands of years ago. Back then, there was no steel, and the only iron that existed was locked up in meteorites and rocks. The only available metals were those that our ancestors found lying about the countryside or submerged in streams, namely copper, gold, and silver. Isn’t it ironic then that the first metals ever fabricated by man would be, by today’s standards, the most expensive?
The reason is simple. These metals are among the only “native” materials, meaning they can be found in nature in their chemically pure form. They’re also shiny — an attribute that led to easy discovery — and malleable, ready for pounding into a pretty trinket to impress that girl you’ve been chasing.
Attractive as these metals are, however, they’re pretty wimpy compared to their modern alloys. Tease a little copper wire out of the nearest electrical socket (you might want to turn off the power first) and you’ll see that it’s soft and pliable, an awesome attribute if you want to fabricate a ceremonial headdress for the chief, but not worth a darn if you need a durable weapon with which to fight for his daughter’s hand.
Pounding progress
Then one day, some ancient figured out how to make bronze. Historians a whole lot smarter than me suggest the discovery took place around 4,500 B.C., when stones rich in copper and tin — the alloy’s two key ingredients — were used to line fire pits.
Because copper melts at around 2,000 °F (the hottest part of a rip-roaring campfire) and tin at temperatures much lower than that (about that of a decent pizza oven), it’s likely the two metals simply ran out of the rock and puddled in the bottom of the fire pit during a late-night party somewhere on the Sumerian plains. In the morning, the would-be metallurgists reveled over the metallic discovery, saying, “Hey, dude, check this out. Let’s do that again!”
Hello, Bronze Age
Bronze is an excellent multipurpose metal. It’s much harder than either of its constituent metals alone. It can be pounded or cast into useful shapes like swords, bells, anchors, farming implements, and durable pots with which to cook up a bit of musk ox. It was used to make the first currency, build better buildings, and led to far more efficient ways to wage war.
