Grizzly G9901 Owner's Manual page 50

Symptom
Machine has vibration or
noisy operation.
Operation and Work Results
SYMPTOM
Tool slips in collet.
Breaking tools or cutters.
Machine is loud when
cutting. Overheats or bogs
down in the cut.
Workpiece vibrates or
chatters during operation.
Table hard to move.
Bad surface finish.
-48-
Possible Cause
1. Motor or component is loose.
2. Belt is slapping belt cover/head-
stock; is worn or loose.
3. Belt pulley is loose.
4. Motor mount loose/broken.
5. Machine is incorrectly mounted or
sits unevenly.
6. Workpiece is loose.
7. Motor fan is rubbing on fan cover.
8. Cutter is at fault.
9. Bit is chattering.
10. Motor bearings are at fault.
POSSIBLE CAUSE
1. Collet is not fully drawn up into
spindle taper.
2. Wrong size collet.
3. Debris in collet or in spindle taper.
4. Taking too big of a cut.
1. RPM and or feed rate is too fast.
2. Cutting tool getting too hot.
3. Taking too big of a cut.
1. Excessive depth of cut.
2. Dull cutting tools.
1. Table locks not tight.
2. Quill lock not tight.
3. Workpiece not securely clamped to
table or into mill vice.
4. RPM and feed rate too high.
1. Table locks are tightened down.
2. Chips have loaded up on ways.
3. Ways are dry and in need of lubri-
cation.
4. Gibs are too tight.
1. Wrong RPM or feed rate.
2. Dull cutting tool or poor cutting tool
selection.
3. Wrong rotation of cutting tool.
4. Workpiece not securely clamped.
Possible Solution
1. Inspect/replace stripped or damaged bolts/nuts, and
re-tighten with thread locking fluid.
2. Replace/realign belt (refer to Page 52 & 53).
3. Replace shaft, pulley, setscrew, and key as
required.
4. Tighten/replace.
5. Tighten/replace anchor studs in floor; relocate/shim
machine.
6. Use the correct holding fixture and reclamp
workpiece.
7. Replace dented fan cover; replace loose/damaged
fan.
8. Replace out-of-round cutter; replace/resharpen cut-
ter; use appropriate feed rate and cutting RPM.
9. Replace/sharpen bit; index bit to workpiece;
use appropriate feed rate and cutting RPM (see
Page 32).
10. Test by rotating shaft; rotational grinding/loose shaft
requires bearing replacement.
CORRECTIVE ACTION
1. Snug up draw bar.
2. Measure tool shank diameter and match with
appropriate diameter collet.
3. Remove oil and debris from collet and spindle taper.
4. Lessen depth of cut and allow chips to clear.
1. Set correct RPM and feed rates (see Page 32).
2. Use coolant fluid or oil for appropriate application.
3. Lessen depth of cut and allow chips to clear.
1. Decrease depth of cut.
2. Use sharp cutting tools.
1. Tighten down table locks.
2. Tighten quill lock.
3. Check that clamping is tight and sufficient for the
job. Make sure mill vice is tight to the table.
4. Use appropriate RPM and feed for the job (see
Page 32).
1. Make sure table locks are fully released.
2. Frequently clean away chips that load up during
milling operations.
3. Lubricate ways and handles.
4. Adjust gibs (see Page 49).
1. Adjust for appropriate RPM and feed rate (see Page
32).
2. Sharpen cutting tool or select a better cutting tool for
the intended operation.
3. Check for proper cutting rotation for cutting tool.
4. Properly secure workpiece.
Model G9901/G9902/G9903 Milling Machine