Grizzly G8688 Lathe User Manual


 
-32-
Model G8688 (Mfg. 3/09+)
SYMPTOM POSSIBLE CAUSE CORRECTIVE ACTION
Entire machine vibrates
excessively upon startup
and while running.
1. Workpiece is unbalanced.
2. Loose or damaged belt(s).
3. V-belt pulleys are not properly
aligned.
4. Worn or broken gear present.
5. Chuck or faceplate has become
unbalanced.
6. Spindle bearings badly worn.
1. Reinstall workpiece so it is as centered with the
spindle bore as possible.
2. Tighten/replace the belt as necessary.
3. Align the V-belt pulleys.
4. Inspect gears and replace if necessary.
5. Rebalance chuck or faceplate; contact a local
machine shop for help.
6. Replace spindle bearings.
Bad surface finish. 1. Wrong RPM or feed rate.
2. Dull tooling or poor tool selection.
3. Too much play in gibs.
4. Tool too high.
1. Adjust for appropriate RPM and feed rate.
2. Sharpen tooling or select a better tool for the intend-
ed operation.
3. Tighten gibs.
4. Lower the tool position.
Can't remove tapered tool
from tailstock quill.
1. Quill had not retracted all the way
back into the tailstock.
2. Debris was not removed from taper
before inserting into quill.
1. Turn the quill handwheel until it forces taper out of
quill.
2
. Always make sure that taper surfaces are clean.
Cross slide, compound
slide, or carriage feed has
sloppy operation.
1. Gibs are out of adjustment.
2. Handwheel is loose.
3. Lead screw mechanism worn or
out of adjustment.
1. Adjust gib screw(s) (see Page 35).
2. Tighten handwheel fasteners.
3. Tighten any loose fasteners on lead screw mecha-
nism.
Cross slide, compound
slide, or carriage feed
handwheel is hard to
move.
1. Gibs are loaded up with shavings,
dust, or grime.
2. Gib screws are too tight.
3. Backlash setting too tight (cross
slide only).
4. Bedways are dry.
1. Remove gibs, clean ways/dovetails, lubricate, and
readjust gibs.
2. Loosen gib screw(s) slightly, and lubricate bedways.
3. Slightly loosen backlash setting by loosening the
locking screw and adjusting the spanner ring at the
end of the handle.
4. Lubricate bedways and handles.
Cutting tool or machine
components vibrate exces-
sively during cutting.
1. Tool holder not tight enough.
2. Cutting tool sticks too far out of tool
holder; lack of support.
3. Gibs are out of adjustment.
4. Dull cutting tool.
5. Incorrect spindle speed or feed
rate.
1. Check for debris, clean, and retighten.
2. Reinstall cutting tool so no more than
1
3 of the total
length is sticking out of tool holder.
3. Tighten gib screws (see Page 35) at affected com-
ponent.
4. Replace or resharpen cutting tool.
5. Use the recommended spindle speed.
Inaccurate turning results
from one end of the
workpiece to the other.
1. Headstock and tailstock are not
properly aligned with each other.
1. Realign the tailstock to the headstock spindle bore
center line (see Page 36).
Chuck jaws won't move or
don't move easily.
1. Chips lodged in the jaws. 1. Remove jaws, clean and lubricate chuck threads,
and replace jaws.
Carriage won't feed. 1. Gears are not all engaged.
2. Gears are broken.
3. Loose screw on the feed handle.
1. Adjust gear positions.
2. Replace.
3. Tighten.
Operation and Work Results