Popular Woodworking 2008-06 № 169, страница 30

compound cuts such as those used for creating cabriole legs, reproduce or make duplicate parts with a high degree of accuracy, cut a variety of joints including dovetails and mortise and tenons, cut circles, square notches, make angled cuts, and of course they can cut any type of a straight line - both with a fence and freehand.

The band saw gets its name because the blade that cuts the stock is a narrow steel strip where the ends have been welded together to form a continuous band. It is usually not the first machine purchased by the home woodworker, but it can be one of the most useful machines in the shop. Band saws are not typically used in the final milling process to make boards square or S4S (surfaced on four sides) but they can be wonderful tools to help cut rough lumber to length and width before starting the milling process.

They are sold in a variety of sizes. I have heard over the years that the size ofa band saw is determined by the wheel diameter or die distance from the blade to the throat. This measurement is the limiting factor on how wide wood can be cut to the left of the blade. Most home-shop band saws are 10" to 14" in size. However, this measurement or size limitation is only one part of the equation. The other consideration when determining the size of a band saw is the depth of cut it

The depth of cut on a band saw is determined by the overall distance from the table to the guides when they are at their highest point. Generally, the larger the machine the more powerful it will be and the more capacity it will have. Bigger machines can typically accommodate larger-width blades which could be desirable for certain applications of re-sawing. All saws should be able to handle narrow blades.

The size of the table is usually not a consideration when buying a band saw, but the larger the table, the more support and control the saw will afford. Today, some manufacturers such as Powermatic offer extension tables that fill the void between the left side of the table and the upper arm. The size of the table will determine how much it can tilt to both the right and left of the

blade. Most band saws can tilt 45° to the right and about 10° to the left.

The purpose of this article is not about how to select blades or whether or not to de-tension them when not in use. It is not about how to align the wheels or discuss the difference between bearing guides or cool blocks. Nor is it about the techniques of how to re-saw lumber, cut cabriole legs or how to make and use the variety of jigs and fixtures that make fancy cuts. There are a lot of good articles and books that have already been written on those topics.

The purpose of this article is to explain the proper and safe techniques for using this saw. For the purpose of proceeding, from this point on we will assume that the mechanical function of the saw such as blade tracking and blade tension, as well as the adjustment of the guides, are all in proper working order and adjusted correctly.

Band saws are quite easy to use and fairly safe, as long as you understand two basic fundamentals of the machine: the action of the cut and how to plan the cut.

Cutting Action

Band saws do not create a kicking or throwing motion toward the operator. Instead they have pinch points. Because the cutting action of the blade is created by a downward motion, all cutting forces are directed toward the table. This all but eliminates kickback toward the operator. It can, however, pull the stock, especially small offcuts, through the throat plate toward the bottom guides.This in turn could possibly break the blade, damage the throat plate, wreck the guides and throw off the tracking, any of which could create risk to both the machine and operator. So what should you do with all those small offcuts? It is tempting to tap them away with another piece of wood or with your fingers. However, this would put your hands within the 3" rule — which is in violation of safety rule number 1. These small offcuts cause no harm until you put them in motion. More than likely, the next piece of wood to be cut will push those small pieces out of the way. When the last cut is complete, wait for the blade to come to a complete stop before removing any offcuts next to the blade.

Pinch points. Ifyou have to wake a sculptural a table, be aware of pinch points, and plan the cut

' that will result in wood that's not flat to the • this problem.

12 ■ Popular Woodworking June 2008