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Wood Digest's Education In Print has quickly come a full circle. For the last five years, EIP articles focused on Wood Structure and Properties, Wood Machining Technology, Wood Sanding and Finishing, Engineering and Management, and most recently, an Introduction to Blueprint Reading. One of the most popular online courses and group of articles was the Wood Machining Technology Series. For this reason, Wood Digest will again offer Wood Machining Technology articles that support this online class. These will be new articles with updated material blended with traditional viewpoints.

The textbook, Circular Saws by Eric Stephenson will continue to be the prominent textbook for the course. Other reference materials will be introduced as the course and this article series develop. Interestingly, since this course was started four years ago, very few, if any, new textbooks became available on the subject of modern wood machining practices. Most of the reference materials are either out of date or out of print, making them unusable for students. These older reference materials are still readily available in print form or electronic databases in libraries, Internet or the used book market. Extremely old references are interesting to read to see the many changes to saw geometry as well as the many remaining design features.

For example, the most prominent circular saw feature to change is in the field of saw tooth properties. Hard, replaceable, repairable sintered powder metal teeth replaced high-speed steel teeth many years ago. Initially, these tips could not be sharpened to the degree of high-speed steel. Although still true to some extent, the metal properties are vastly improved and initial sharpness is much finer. Their main feature is longer lasting teeth before subsequent sharpening. Sharpened by accurate machinery, sintered metal powder teeth include Stellite, tungsten carbide tipped (TCT) and others. These are examples of industry standard products that will be covered in this course.

This course and series of articles will also cover band saw technology and cutterhead knife technology. Introduced four years ago in Education In Print, the concept of a dual color on the body of a cutting tool was a new safety feature. When spinning, the colors blend together, warning the operator that the tool is still spinning. Safety will continue to be the No. 1 consideration in any machining operation. New and safer machining practices using cutting tools will be addressed and studied throughout the course. Of course, traditional safety practices will not be forgotten. As the technology improves and changes, safe work practices change at the same pace.

TIMELINE OF TOOLING

In Chapter One of the Circular Saws textbook, the historical timeline of early circular saws through current technology is covered. This introduction gave reference to steel manufacturing and the importance of carbon and heat to produce the steel used in saw bodies. Since these early days of steel production, other metals have been added to toughen, maintain flexibility and to strengthen the steel, giving it properties far superior than the earlier steels.

These alloyed structural improvements of steel have radically changed its properties. Modern tooling steel has different grades, each suited for the machining requirements of industry. The push for faster and better products led to the development of CNC equipment. As the equipment developed and improved, steel needed to be improved to withstand the rigors of fast travel, high revolutions per minute, deep cuts all with repeatable accuracy. Quickly, it was determined that high-speed steel would not keep an edge long enough. While carbide was good for solid woods, the introduction of composite and foreign woods pushed for harder diamond impregnated steels.

Coupled with steel and machinery improvements, devices used to balance and weigh cutterheads, sharpen saws and hone were developed to increase accuracy. This class will describe the benefits of multiknife cutting to your production, the safety aspects of accurate grinding and dynamically balanced cutterheads. Although this may generalize the timeline of tooling, we must assume that tooling advances will continue as the industry demands and technology allows.