22.Apr.2012 Vocabulary

Vocabulary is important in communicating technical details with accuracy. Almost everything has a name and it is helpful to be able to explain and discuss key concepts without pausing to explain every tool, feature function or fastener along the way.   I will be posting weekly vocabulary focusing on specific themes or questions I ran into during the week.

Cutting Vocabulary:

Kerf:  The width of grove made by a cutting tool.  (The American Heritage Dictionary)

The width of a kerf varies depending on the cutting tool being used.  The kerf can be less than 1/16” inch when cutting with jeweler’s saws or as large as ¼” or more when utilizing CNC routers. Depending on the process used and the precision required, offsetting the cut to prevent removing excess material may be necessary.  Nesting patterns are especially sensitive to the effect of kerf because material is removed symmetrically from both parts.  As a result it is often impossible to simultaneously cut tight fitting interlocking parts when they share the kerf of a cutter.

One tool capable of cutting tight fitting nesting parts is laser cutters. This useful link shows how to determine the kerf of a laser cutter.

http://www.adafruit.com/blog/2011/07/13/finding-the-kerf-of-a-laser-cutter/

Rip Cutting: Rip cuts are cutting operations made parallel to the direction of the grain.

Table saws and band saws are frequently used for rip cuts.

Cross Cutting: Cross cuts are cutting operations made parallel to the grain.  As the cutter encounters the fibers of the wood at their strongest, slower feed rates are required for quality cuts.

Miter saws and radial arm saws and band saws are frequently used for cross cuts.  Table Saws are also used for cross cutting when fitted with cross cut sleds and blades.  It is also worth mentioning that when cutting plywood, due to the alternating grain directions of the plys, any cutting direction will behave like a crosscut.

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