4. How much unplanned
downtime do we have?
Various factors can cause unplanned downtime,
and many have to do with improper band saw settings or using the incorrect blade for the job.
Consider a pinching situation when cutting a
large I or H beam. Internal stresses in the work build
as the blade cuts through. Once those stresses release, the cut portion of the workpiece may physically move, begin to close in behind the cut path
left by the blade, and grab the back of the blade,
causing it to stall.
;e same thing happens when, say, cutting a
branch on a tree with a hand saw. At a certain point,
When band sawing metal, a wider kerf can help
eliminate the problem. Specialty blades designed
for structural beams and similar materials pro-
duce an extra-heavy kerf, minimizing the chance of
pinching during an operation.
Back to the tree example, there’s another rea-
son that the hand saw becomes pinched. ;e cut
surface the hand saw produces usually isn’t the
smoothest. When a tree pinches the saw, it tends to
get stuck in place against the rough ridges of your
cut in progress. If the surfaces were smoother, the
tree branch wouldn’t become stuck so easily.
Similarly, when you are band sawing metal, a
smooth cut surface allows the backing steel of the
blade to slide more freely, so you avoid getting stuck
by pinching. Modern blade technology, including
the tapered back, makes this smooth surface possible (see Figure 3).
Blade changeover also adds to your downtime.
To reduce the changeover frequency, you may find
that it is cost-e;ective to pay the extra money to
purchase a high-end blade. Also, before you purchase your next band saw machine, consider that
blade length also a;ects changeover frequency. A
band saw runs in a loop, and the shorter that loop
Modern Machine Tool has been building
cutoff lathe machines for almost a century.
Our lathes have evolved over the years into a
completely automatic operation—from feeding to cutting to finishing. Our compact cast
iron slide unit offers rigidity with the speed
and serviceability of linear technology. The
precision ground, ball-screw driven slides with
high torque digital drives provide easy set up
and increased tool life. An optional two axis
servo slide is available for simple turning,
boring and drilling operations. These systems
can handle material . 25” to 8”. Call us today
and find out how speed and precision have
• Two Axis Slide
• High Torque Digital Drive
• Menu Prompted Touch Screen
• Digital Read Out or Servo Positioned
• Heavy Duty Stock Stops
THE HOT RODS OF CUTOFF LATHES
Cut to the Finish
Follow us on
Type in MMTco
2005 Losey Avenue • Jackson, MI 49203 • 517.788.9120 • ModernMachine Tool.com
A smooth cut surface like this, produced with a blade having a tapered back, improves quality and helps avoid problems like blade pinching.