Southbend SB1017 - Manual (Page 27)

For Machines Mfg. Since 8/09 Model SB1017
-25-
O P E R A T I O N
blade selection
Blade Tension
Proper tension is essential to avoid vibration,
twist, or`slippage on the wheels. A correctly
tensioned blade provides long life, straight cuts,
and efficient cutting times.
The three major signs of incorrect tension are:
1) The blade stalls in the cut and slips on the
wheels, 2) the blade frequently breaks, and 3) the
cuts are not straight.
To tension the blade on the bandsaw:
1. Make sure the blade is tracking properly
(refer to Blade Tracking on Page 35).
2. DISCONNECT BANDSAW FROM POWER!
3. Loosen and slide the blade guide as far out
as it will go, then tighten it down again.
4. Turn the tension knob in Figure 29
clockwise to tighten the blade or clockwise to
loosen the blade.
5. Using moderate finger pressure, push
against the side of the blade. If the blade
flexes more than 1 ⁄
8
", tighten the blade
tension knob further, then repeat this step.
Figure 29. Adjusting blade tension.
Blade
Tension
Knob
Blade Breakage
Many conditions may cause a bandsaw blade to
break. Some of these conditions are unavoidable
and are the natural result of the stresses to
which bandsaw blades are subjected. Other
causes of blade breakage are avoidable.
The most common causes of avoidable blade
breakage are:
• Faulty alignment or adjustment of the blade
guides.
• Forcing or twisting a wide blade around a
tight radius.
• Feeding the workpiece too fast.
• Dull or damaged teeth.
• Over-tensioned blade.
• Top blade guide assembly set too high above
the workpiece. Adjust the top blade guide
assembly so that there is approximately 1 ⁄
4
"
between the bottom of the assembly and the
workpiece. Understand that with smaller
workpieces, this may not be possible. In
these cases, simply adjust the blade guide as
far down as possible.
• Using a blade with a lumpy or improperly
finished braze or weld.
• Continuously running the bandsaw when not
in use.
• Leaving the blade tensioned when not in use.
• Using the wrong blade pitch (TPI) for the
workpiece thickness. The general rule of
thumb is to have no fewer than three teeth
in contact with the workpiece when cutting.
!