Wellsaw V20-24 - Manual (Page 7)

5
NOTES ON SAWING
It is widely recognized that a profi cient operator is a key to op-
timum bandsawing. He makes certain the machine is properly
maintained and adjusted for dependable operation. He carefully
sets up each cutting job to prevent damage to the machine and
obtain the best performance from the equipment.
Experienced blade dealers can be very helpful in selecting the
grade and proper tooth blade for each sawing job. All blades
should be straight, have sharp teeth with uniform set, and be “bro-
ken in” at a reduced feed rate to obtain good cutting performance
and blade life.
Every cutting situation has special characteristics requiring some
experimentation to determine which blade, speed and feed rate
will achieve the most satisfactory result. Cutting charts indicate a
good starting point, but must be modifi ed by direct experience if
optimum performance is desired.
Here are some helpful pointers for adjusting speed and feed for
cutting performance.
1. Make sure the saw is cutting a good chip from the workpiece.
2. Watch for blue chips or excessive “smoke” indicating heat
in the cut which could damage the blade or work harden the
material being cut.
3. Watch for excessive vibration or chatter marks on the cut-off
piece indicating possible damage to the saw teeth by “ham-
mering”
4. Check the cut-off for fl atness. A dull blade or excessive feed
will produce a “belly” in the cut.
5. Inspect the blade for worn, rounded or shiny cutting edges.
avoid force cutting which will allow chips to “weld” to saw
teeth and eventually cause the teeth to be stripped off the
blade.
6. When experimenting, start with a slow speed and feed rate.
Gradually increase blade speed and then feed pressure by
small amounts until adverse effects are noted. You can then
set the speed and feed at a reasonable level for continuous
cutting. Remember that blade speed and feed pressure must
be balanced to keep cutting a good chip.
CUTTING TIPS
1. Select blade and speed for material being cut. Use the
coarsest tooth blade suitable for the workpiece while proving
for at least two teeth cutting at all times. Use fastest suitable
band speed and minimum feed source adequate to produce
good cutting action. Work with work-hardening steels, main-
tain a steady feed; do not let teeth rub without cutting.
2. Keep the blade guides as close as possible to the workpiece.
3. If teeth wear off unusually fast, use a slower band speed.
PREMATURE DULLING OF BLADE
1. Feed rate too high or low. Check recommendation.
2. Blade speed too slow or too fast.
3. Faulty material; heavy scale, hard spots, etc.
4. Verify material analysis
5. If coolant fl ow is not covering saw teeth, increase coolant
fl ow rate.
6. If saw is vibrating in cut, reduce a blade speed or increase
feed rate.
7. Chipped or broken tooth may be lodged in cut.
8. “Chip welding” caused by improper feed and speed.
9. Incorrect coolant mixture.
10. Incorrect blade selection.
11. Improper break-in of new blade. New blades should be run
initially with reduced feed pressure for approximately 50 to
100 square inches.
12. Saw blade teeth may be hitting blade guides. Check for
proper blade size.
SAW BLADE VIBRATION
1. Incorrect blade speed for material.
2. Blade tension insuffi cient.
3. Back-up bearing may be worn.
4. Incorrect choice of saw tooth pitch.
5. Incorrect coolant mixture.
6. Incorrect feed setting. Increase feed.
7. Work piece not fi rmly clamped to vice.
8. Worn or improperly adjusted saw guides. Check and make
necessary adjustments.
BLADE TEETH CHIPPING OR RIPPING OUT
1. Blade pitch too coarse. Use a fi ne pitch saw blade on thin
work sections.
2. Improper break-in of new blade. Do not start a new blade in
an old cut.
3. Work piece not held fi rmly enough. Clamp work securely.
4. Introduce cooling if it is not being used.
5. Faulty material; scale or hard spots.
6. Blade gullets may be loaded. Use higher viscosity lubricant
or coolant.
7. Blade speed and feed may need adjustment.
TROUBLE SHOOTING