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Lathe Operation
symptom
possible Cause
Entire machine
1. Workpiece is unbalanced.
vibrates upon
startup and while
2. Loose or damaged V-belt(s).
running.
3. V-belt pulleys are not properly aligned.
4. Worn or broken gear present.
5. Chuck or faceplate is unbalanced.
6. gears not aligned in headstock or no
backlash.
7. Broken gear or bad bearing.
8. Workpiece is hitting stationary object.
9. spindle bearings at fault.
Bad surface finish.
1. Wrong spindle speed or feed rate.
2. dull tooling or poor tool selection.
3. tool height not at spindle centerline.
4. too much play in gibs.
tapered tool difficult
1. Quill is not retracted all the way back into
to remove from
the tailstock.
tailstock quill.
2. Contaminants not removed from taper
before inserting into quill.
Cross slide,
1. gibs are out of adjustment.
compound rest, or
2. handwheel is loose or backlash is high.
carriage feed has
sloppy operation.
3. Leadscrew mechanism worn or out of
adjustment.
Cross slide,
1. dovetail ways loaded with shavings, dust,
compound,
or grime.
or carriage
2. gib screws are too tight.
handwheels hard to
move.
3. Backlash setting too tight.
4. Bedways are dry.
Cutting tool
1. tool holder not tight enough.
or machine
2. Cutting tool sticks too far out of tool holder;
components vibrate
lack of support.
excessively during
3. gibs are out of adjustment.
cutting.
4. dull cutting tool.
5. incorrect spindle speed or feed rate.
Model G0750G (Mfg. Since 11/12)
possible solution
1. re-install workpiece as centered with the spindle
bore as possible.
2. re-tension/replace the V-belt(s) as necessary (see
page 75).
3. Align the V-belt pulleys.
4. inspect gears, and replace if necessary.
5. re-balance chuck or faceplate; contact a local
machine shop for help.
6. Adjust change gears and establish backlash.
7. replace broken gear or bearing.
8. stop lathe immediately and correct interference
problem.
9. reset spindle bearing preload or replace worn
spindle bearings.
1. Adjust for appropriate spindle speed and feed rate.
2. sharpen tooling or select a better tool for the
intended operation.
3. Adjust tool height to spindle centerline (see page
45).
4. tighten gibs (see page 72).
1. turn the quill handwheel until it forces the tapered
tool out of quill.
2. Clean the taper and bore, then re-install tool.
1. Adjust gibs (see page 72).
2. tighten handwheel fasteners, adjust handwheel
backlash to a minimum (see page 71).
3. Adjust leadscrew to remove end play (see page
72).
1. remove gibs, clean ways, lubricate, and re-adjust
gibs.
2. Loosen gib screw(s) slightly (see page 72), and
lubricate bedways.
3. slightly loosen backlash setting (see page 71).
4. Lubricate bedways/ball oilers.
1. Check for debris, clean, and re-tighten.
2. re-install cutting tool so no more than
length is sticking out of tool holder.
3. Adjust gibs at affected component (see page 72).
4. replace or resharpen cutting tool.
5. use the recommended spindle speed and feed rate.
⁄
of the total
1
3
-69-
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