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 45°F. 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. Drill Press 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. 3-4