Model G0768/G0769 (Mfd. Since 8/15)
-79-
Lathe Operation
Symptom
Possible Cause
Possible Solution
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.
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 83).
Tapered tool difficult
to remove from
tailstock quill.
1. Quill not fully retracted into tailstock.
2. Contaminants not removed from taper
before inserting into quill.
1. Turn quill handwheel until tapered tool is forced out
of quill.
2. Clean taper and bore, then re-install tool.
Cross slide,
compound rest, or
carriage feed has
sloppy operation.
1. Ways loaded with shavings, dust, or grime.
2. Gibs are out of adjustment.
3. Handwheel loose or excessive backlash.
4. Leadscrew mechanism worn or out of
adjustment.
1. Clean ways and relubricate.
2. Adjust gibs (see
Page 83).
3. Tighten handwheel fasteners, adjust handwheel
backlash to a minimum (see
Page 82).
4. Adjust leadscrew to remove end play (see
Page
82).
Cross slide,
compound,
or carriage
handwheels hard to
move.
1. Ways loaded with chips, dust, or grime.
2. Gibs are too tight.
3. Backlash setting too tight.
4. Bedways are dry.
5. Half nut lever engaged.
1. Clean ways and lubricate.
2. Loosen gibs slightly (see
Page 83).
3. Slightly loosen backlash setting (see
Page 82).
4. Lubricate bedways.
5. Disengage half nut lever for manual feeding.
Cutting tool
or machine
components vibrate
excessively 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. Re-install cutting tool so no more than
1
⁄
3
of the total
length is sticking out of tool holder.
3. Adjust gibs at affected component (see
Page 83).
4. Replace or resharpen cutting tool.
5. Use the recommended spindle speed and feed rate.
Workpiece is
tapered.
1. Headstock and tailstock not properly
aligned.
1. Re-align tailstock to headstock spindle centerline
(see
Page 39).
Chuck jaws will
not move or do not
move easily.
1. Chips lodged in jaws or scroll plate.
1. Remove jaws, clean and lubricate scroll plate, then
replace jaws.
