machines do a lot of the work for you. Once a cut is going, you can relax to some extent.
•You won’t have to spend a lot of money to learn to be a machinist. You will, however, need to spend money for tools.
For the many positives this trade has to offer, there are also a few negatives. The following are things I don’t like about this trade.
•Because you are producing solid, tangible parts, it is easy for others to follow your progress and criticize what you’re doing.
•The better you are, the more work you’ll get. If you are accurate and efficient, youll end up getting a lot of “hot” jobs and, believe me, there will be many of them.
•It can be difficult to erase mistakes. For example, a draftsman or engineer can hit a “delete” button or use an eraser to quickly wipe out a mistake, and then proceed from that point. If machinists drill a hole in the wrong place or cut a diameter too small, they may have to start over. There is no “delete” button for machinists. This can be costly, both financially and psychologically, depending on how many parts were made wrong, how much time was spent on each part, and how the critics react.
•Machining is very tool intensive and you can’t work efficiently without them. You are constantly looking for, changing, sharpening, buying, making, or borrowing tools. Sometimes I’m envious of the computer people who have all their tools right there on the computer screen, just a few clicks away.
•For some reason, machinists are often treated like second-class citizens. One example is air conditioning. You will often find in a company air conditioning everywhere except the machine shop.
I could list more but, all in all, I believe the positives outweigh the negatives by quite a large margin.
I suspect many trades and professions have rules, methods, and ideas that get passed along from one generation to the next. In this book, I’ll attempt to identify and correct some of the misinformation in our trade. One “myth” that comes to mind is that “You should never turn off a surface grinder once the wheel is dressed.” The fact is: you can turn the wheel on and off as much as you like without dressing the wheel, as long as the wheel is mounted tightly enough so that it doesn’t move or shift on the spindle.
No matter how hard we try to avoid making extra work for ourselves, things go wrong. Taps break, cutters break, materials warp, indicators lie, digital readouts skip, milling heads move, vise handles jam, and mikes and drawing are misread. Parts fall on the floor, disappear, or get made out of the wrong material. It’s Murphy, of course (from Murphy’s Law). I’ve spent the better part of my life trying to get one over on that guy. It’s not easy, but I’ve nailed him many thousands of times now, and it’s always very satisfying.
I’ll show you ways of sharpening taps and cutters so they won’t break, and how to remove taps, screws, and cutters that have broken. I’ll show you ways to close down oversize holes, minimize material warpage, repair threads, and plan jobs to avoid trouble.
Most of the suggestions I’ve made in this book are techniques and rules of thumb that work for me. It doesn’t mean they’ll work for you or that you’ll even agree with them. I’m always looking for better and easier ways to do things. I’m always experimenting and streamlining techniques that work for me. I suggest you do the same.
To present these suggestions in a concise, easy-to-read format, I’ve chosen simply to list them.
Some of these rules and suggestions are presented as statements; others are presented as questions followed by answers. Some of these rules stand alone, and some are followed by more complete explanations.
For those readers who already know everything, I’ve included a chapter especially for you. It’s called “Tell me something I don’t know.” In this chapter, I’ll present some little known, little understood, and in some cases not very useful information about metalworking. For example, how many of you out there know how to make a Slinky®? I mean a real Slinky, not just a curly chip. In this chapter, I’ll tell you.
In the back of the book, I’ve included an appendix with drawing of tools that I frequently use in the shop.
New to the Second Edition
Several improvements have been made to the second edition of Machine Shop Trade Secrets, including:
•Full-color design and photos. The first edition was a one-color book; here we’ve gone to full-color. The photo images are sharper and clearer because they’re in full color.
•Improved layout. The book has been redesigned so that most topics are self-contained on a page. Even more important, figures and the accompanying text are now almost always on the same page, making it easier for you to follow them.
•Tables and featured boxes have been added. These features highlight the information that might otherwise get lost in text.
•Chapter 15 on Computer Numerical Control has been thoroughly revised and updated. A lot more focus in this chapter has been placed on computer-aided design, manufacturing, programming, and CNC machines.
•Summary tables appear at the end of most chapters. These tables provide you the opportunity to easily review the suggestions within that chapter, whether to help you find specific suggestion as you approach the chapter, or to review after reading the chapter.
•The end-of-book index has been thoroughly revised and increased considerably in size and detail.
It’s been said that “metal is man’s servant.” I’ve spent many years pursing that goal — so let’s get started sharing what I’ve learned!
James Harvey Garden Grove, CA
As machinists, how often are we asked to produce hardware that was needed “yesterday?” The answer is “quite often” because shop personnel try to keep squeaky wheels greased. Squeaky wheels come at us from all sides, including:
•Production workers count on machinists to keep lines going.
•Research and development employees count on machinists to keep new product programs on track.
•Maintenance specialists count on machinists for repair parts.
The bottom line is this: when people want parts, they want parts. They don’t want excuses or anything else. That’s one of the beauties of being a machinist. Your responsibilities are clear and simple. If you can get people their blessed parts, they’ll go away.
Most people, including myself, don’t want to work any harder or faster than necessary. At times, though, when the crisis monkey is on us, we have to get the lead out and get going. Crisis machining can actually be fun once in a while. Generally speaking, any glory to be had usually comes from helping someone through a crisis. If nothing else, it can be a nice change of pace. The hours tend to go by quickly when you’re working on a “hot” job.
