The portable, hand-held jig saw is one of the most useful power woodworking tools. Some of the common uses of the jig saw around the shop include cutting large panels down to manageable size, before making finish cuts on your table or miter saw, or cutting tight curves without a band saw. And nothing cuts holes in boards or panels like a jig saw.
Jig saws also see service outside the shop, for woodworking on-location. Because the saw is lightweight and easy to handle, it can be used to work with everything from small pieces of molding to large plywood panels.
Two important advances in technology around 20 years ago have produced a new generation of jig saws: these saws have orbital action and electronic control. Electronic control, which involves the use of microchips helps the new saws maintain constant cutting speed, even under heavy loads. This improvement prolongs the life of the motor, while improving cutting efficiency. With variable speed control, the saw maintains the desired speed under all load conditions.
The other important advance in jig saws is a change in the stroke of the saw blade. In orbital action jig saws, the blade moves forward during the upward, cutting stroke. The blade then returns to the normal perpendicular position for the downstroke. The total amount of forward movement is not much: only about 1/16″. But this is enough to provide significant improvement in cutting efficiency.
How does orbital action improve cutting efficiency? Since the wood chips and dust are ejected during each stroke, rather than building up around the blade, the friction of cutting is reduced. This means a cooler, longer lasting saw blade. The extra forward “kick” of the saw blade also speeds the saw through softer woods. If you have never tried an orbital action jig saw on a piece of soft pine, run down to your nearest store and give one a try. You won’t believe the way these saws slice through pine.
On the other hand, orbital action is not suitable for every purpose. The same orbital motion which speeds the jig saw cut also leaves a rougher surface behind. If you are making a finish cut, you won’t want orbital action.
Fortunately, the orbital motion is variable in these saws: you can adjust the amount of forward motion from none (straight reciprocating action) to a maximum of about 1/16″, depending on the model. Most saws also provide a couple of intermediate positions between these extremes.
Several factors influence the amount of orbital action you select. Orbital motion is unsuited for use on metals, for example. Even thin wood stock should not be tackled with the orbital action. The forward motion of the blade can start the stock vibrating, destroying the accuracy of your cut. You should reduce the amount of orbital motion when cutting hardwoods, as well: the harder the wood, the less orbital motion you want.
On the other hand, for straight, fast cutting of soft woods, turn the orbital action up all the way. The resulting cut won’t be quite as smooth as without the orbit, but the time saved can be substantial when a finish cut is not required.
Choosing a Jig Saw
What should you look for when selecting a new jig saw? First consider what you will do with the saw. How much do you intend to use it? For what kind of work? Will it get knocked around a bit, as in on-location work? Based on your anticipated usage, price is the single most important consideration. You get what you pay for in terms of features and durability.
Please read the continuation in Part #2 of this article.