Grizzly G0791 Owner's Manual page 87

Mill
Symptom Possible Cause
Tool loose in spindle. 1. Tool is not fully drawn up into spindle taper.
2. Debris on tool or in spindle taper
3. Taking too big of a cut.
Breaking tools or 1. Spindle speed/feed rate is too fast.
cutters.
2. Cutting tool is too small.
3. Cutting tool getting too hot.
4. Taking too big of a cut.
5. Spindle extended too far down.
Workpiece or tool 1. Table locks not tight.
vibrates or chatters
2. Workpiece not secure.
during operation.
3. Spindle speed/feed rate is too fast.
4. Spindle extended too far down.
5. Quill lock lever not tight.
6. Gibs too loose in table
Table is hard to 1. Table locks are tightened down.
move.
2. Chips have loaded up on ways.
3. Ways are dry and need lubrication.
Headstock is hard to 1. Headstock lock(s) or gib is at fault.
raise.
2. Headstock lead screw is binding
Bad surface finish. 1. Spindle speed/feed rate is too fast.
2. Dull or incorrect cutting tool.
3. Wrong rotation of cutting tool.
4. Workpiece not secure.
5. Spindle extended too far down.
Cutting results not 1. Table travel is inconsistent.
square.
Spindle overheats. 1. Mill/drill operated at high speeds for
Lack of power at 1. Wrong voltage.
spindle.
Spindle does not 1. Poorly adjusted return spring.
return to highest
2. Worn return spring.
position.
Mill FWD/REV 1. Shorted/disconnected wiring.
switch does not
work.
Model G0791 (Mfd. Since 9/15)
extended period.
Possible Solution
1. Tighten drawbar.
2. Clean tool and spindle taper.
3. Lessen depth of cut and allow chips to clear.
1. Set spindle speed correctly or use slower feed rate.
2. Use larger cutting tool and slower feed rate.
3. Use coolant or oil for appropriate application.
4. Lessen depth of cut and allow chips to clear.
5. Fully retract spindle and lower headstock. This
increases rigidity.
1. Tighten table locks.
2. Properly clamp workpiece on table or in vise.
3. Set spindle speed correctly or use slower feed rate.
4. Fully retract spindle and lower headstock. This
increases rigidity.
5. Tighten quill lock lever.
6. Tighten gibs.
1. Make sure table locks are fully released.
2. Frequently clean away chips that load up during
operations.
3. Lubricate ways.
1. Loosen/replace lock lever and adjust gib.
2. Clean and relubricate headstock leadscrew and
gears.
1. Set spindle speed correctly or use slower feed rate.
2. Sharpen cutting tool or select one that better suits
the operation.
3. Check for proper cutting tool rotation.
4. Properly clamp workpiece on table or in vise.
5. Fully retract spindle and lower headstock. This
increases rigidity.
1. Adjust gibs.
1. Allow mill/drill to cool.
1. Correct voltage.
1. Increase return spring tension.
2. Replace return spring.
1. Inspect circuit boards, wiring connections. Replace/
repair as necessary.
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