saws are much the same with regard to maintenance, operation, and adjustment.
A rule of thumb used by many Seabees is that the width of the blade should be one-eighth the minimum radius to be cut. Therefore, if the piece on hand has a 4-inch radius, the operator should select a 1/2-inch blade. Don't construe this to mean that the minimum radius that can be cut is eight times the width of the blade; rather, the ratio indicates the practical limit for high-speed band saw work.
Blades, or bands, for band saws are designated by points (tooth points per inch), thickness (gauge), and width. The required length of a blade is found by adding the circumference of one wheel to twice the distance between the wheel centers. Length can vary within a limit of twice the tension adjustment range.
Band saw teeth are shaped like the teeth in a hand ripsaw blade, which means that their fronts are filed at 90 to the line of the saw. Reconditioning procedures are the same as those for a hand ripsaw, except that very narrow band saws with very small teeth must usually be set and sharpened by special machines.
Observe the following safety precautions when operating a band saw:
Keep your fingers away from the moving blade.
Keep the table clear of stock and scraps so your work will not catch as you push it along.
Keep the upper guide just above the work, not excessively high.
Don't use cracked blades. If a blade develops a click as it passes through the work, the operator should shut off the power because the click is a danger signal that the blade is cracked and may be ready to break. After the saw blade has stopped moving, it should be replaced with one in proper condition.
If the saw blade breaks, the operator should shut off the power immediately and not attempt to remove any part of the saw blade until the machine is completely stopped.
If the work binds or pinches on the blade, the operator should never attempt to back the work away from the blade while the saw is in motion since this may break the blade. The operator should always see that the blade is working freely through the cut. A band saw should not be operated in a location where the temperature is below 45F. The blade may break from the coldness.
Using a small saw blade for large work or forcing a wide saw on a small radius is bad practice. The saw blade should, in all cases, be as wide as the nature of the work will permit.
Band saws should not be stopped by thrusting a piece of wood against the cutting edge or side of the band saw blade immediately after the power has been shut off; doing so may cause the blade to break. Band saws with 36-inch-wheel diameters and larger should have a hand or foot brake.
Particular care should be taken when sharpening or brazing a band saw blade to ensure the blade is not overheated and the brazed joints are thoroughly united and finished to the same thickness as the rest of the blade. It is recommended that all band saw blades be butt welded where possible; this method is much superior to the old style of brazing.
Figure 3-4 shows a drill press. (The numbers in the figure correspond to those in the following text.) The drill press is an electrically operated power machine that was originally designed as a metal-working tool; as such, its use would be limited in the average woodworking shop. However, accessories, such as a router bit or shaper heads, jigs, and special techniques, now make it a versatile woodworking tool as well.
The motor (10) is mounted to a bracket at the rear of the head assembly (1) and designed to permit V-belt changing for desired spindle speed without removing the motor from its mounting bracket. Four spindle speeds are obtained by locating the V-belt on any one of the four steps of the spindle-driven and motor-driven pulleys. The belt tensioning rod (16) keeps proper tension on the belt so it doesn't slip.
The controls of all drill presses are similar. The terms "right" and "left" are relative to the operator's position standing in front of and facing the drill press. "Forward" applies to movement toward the operator. "Rearward" applies to movement away from the operator.Continue Reading