Machine Shop Trade Secrets. James Harvey

Figure 17-5 Electropolishing Figure 17-6 Mapp® gas torches Figure 17-7 Left-hand drill bits Figure 17-8 Keenserts® Chapter 18 Tell Me Something I Don’t Know Figure 18-1 Slinkys® Figure 18-2 Cone-shaped edge finder Figure 18-3 Kellering Figure 18-4 Friction sawing a file Figure 18-5 Eyeballing a vise Appendices Figure A2-1 Solution to Problem 8 Figure A3-1 Part requiring multiple setups Figure A3-2 Center punch made from a tap Figure A3-3 Dressing shop stones

ACKNOWLEDGEMENTS

      I’d like to thank my wife Reyna for putting up with the long hours I’ve spent in front of the computer instead of with her; my daughter Joanna, who inspired me to stick with the project; and my son Billy for the hours of entertainment he’s provided.

      I am grateful for the support of Ann Fahl, who did much of the editing for the 1st edition, and Robert Weinstein, whose masterful eye was indispensable for bringing together this 2nd edition. I’d also like to thank Janet Romano and John Carleo, from Industrial Press, whose hard work turned this edition into reality.

      And a salute to some of my direct and indirect mentors: Bob Pequinot, Bill Glaze, Mike Davis (deceased), Eugene Sterncorb, and Juvencio Arancibia.

INTRODUCTION

      There are many reference books on the market today, starting with Machinery’s Handbook, that provide much of the technical and reference information a machinist or engineer may ever need. It is still not easy, however, to find a book that provides practical “how to” information that can immediately be put to use to improve one’s machining skills, craftsmanship, and productivity.

      The purpose of this book is to fill that void and provide concrete suggestions that can help you think and produce like an experience machinist. If that’s what you’re looking for, you’ve hit the mother lode.

      This book is directed primarily toward the conventional tool room machinist working in a small shop environment. Many CNC machining suggestions are also included. By virtue of pricing and delivery competition, most small shops have to be very good at what they do. You will find that the equipment and techniques referred to in these pages are commonly seen and used in small machine shops.

      Tool room machinists are the ones called upon to do prototype and low production machining. They may also be called upon to build and maintain tools such as dies, molds, and fixtures, and occasionally sweep the floor. An accomplished machinist should possess many of the skills of a mechanic, craftsman, and problem solver.

      Practitioners of the trade are likely to stay quite busy as they face the daily challenges of getting things done. The trade is well suited for results-oriented people.

      If you’re the type of person who frustrates easily, then you’d better stay away. If you enjoy a challenge, are mechanically inclined, and have an eye for detail, then there are a lot of good reasons to be in the trade. The following list highlights the reasons I like the trade and have stayed with it for so many years.

      •You get to destroy as you create. After nearly forty years working in the trade, I still like making a big mess of chips.

      •It is “real” work and you get to produce solid, tangible products you can see and feel.

      •There are many different areas of the trade you can go into, depending on your preference. Some of the options are: mold making, die making, jig and fixture making, general machining, CNC machining and programming, or in some cases you may get to do all of the above. The techniques used in each of these various aspects of the trade overlap nicely and contribute to your pool of knowledge and experience that can be carried over from one job to the next.

      •You’re in control. Once you become proficient at machining and producing good parts, people will usually leave you alone.

      •You get a chance to use your brain once in a while. The work is not all mundane. You’ll have plenty of opportunity to use your brain, not only to solve shop math problems, but also to solve setup and planning problems. You’ll come to appreciate to some extent the schooling you suffered through as a kid.

      •The job is somewhat physical, but not so much that you will be exhausted at the end of the day. In most cases, you get to move around quite a bit. For my money, it beats sitting behind a desk.

      •Jobs are available and abundant. Machinists are needed in every industrialized area of the world. If you don’t like where you’re working, then you can usually find another job without much difficulty.

      •Machining is something you can do even as you get older. You won’t see many seventy-year-old carpet layers, but you’ll see plenty of seventy-year-old machinists and toolmakers still working.

      •The “fringe” benefits are nice. I’ve used company equipment to make hundreds of personal projects.

      •The work is relatively safe. You don’t hear about many machinists being mortally wounded on the job.

      •You don’t have to spend a lot of time dressing up and grooming for the job.

      •The 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.