Southbend SB owner manual Symptom Possible Cause Possible Solution

For Machines Mfg. Since 5/11 TR O U B L E S H O OTI N G 13" Heavy 13® Gearhead Lathe

Symptom

Possible Cause

Possible Solution

Entire machine	1.	Workpiece is unbalanced.	1.	Re-install workpiece as centered with the spindle
vibrates upon				bore as possible.
startup and while	2.	Loose or damaged V-belt(s).	2.	Re-tension/replace the V-belt(s) as necessary (see
running.				Page 77).
	3.	V-belt pulleys are not properly	3.	Align the V-belt pulleys.
		aligned.
	4.	Worn or broken gear present.	4.	Inspect gears and replace if necessary.
	5.	Chuck or faceplate is unbalanced.	5.	Re-balance chuck or faceplate; contact a local
				machine shop for help.
	6.	Gears not aligned in headstock or	6.	Adjust gears and establish backlash.
		no backlash.
	7.	Broken gear or bad bearing.	7.	Replace broken gear or bearing.
	8.	Workpiece is hitting stationary	8.	Stop lathe immediately and correct interference
		object.		problem.

9.Spindle bearings at fault.9. Reset spindle bearing preload or replace worn spindle bearings.

Bad surface finish.	1.	Wrong spindle speed or feed rate.	1.	Adjust for appropriate spindle speed and feed rate.
	2.	Dull tooling or poor tool selection.	2.	Sharpen tooling or select a better tool for the
				intended operation.
	3.	Tool height not at centerline.	3.	Adjust tool height to centerline (see Page 47).
	4.	Too much play in gibs.	4.	Tighten gibs (see Page 75).
Tapered tool	1.	Quill is not retracted all the way	1.	Turn the quill handwheel until it forces the tapered
difficult to remove		back into the tailstock.		tool out of quill.
from tailstock quill.	2.	Contaminants not removed from	2.	Clean the taper and bore and re-install tapered tool.
		taper before inserting into quill.
Cross slide,	1.	Gibs are out of adjustment.	1.	Adjust gib screw(s) (see Page 75).
compound, or	2.	Handwheel is loose or backlash is	2.	Tighten handwheel fasteners, adjust handwheel
carriage feed has		high.		backlash to a minimum (see Page 74).
sloppy operation.	3.	Leadscrew mechanism worn or out	3.	Adjust leadscrew to remove end play (see Page 75).
		of adjustment.
Cross slide,	1.	Dovetail slides loaded with	1.	Remove gibs, clean ways/dovetails, lubricate, and
compound, or		shavings, dust, or grime.		re-adjust gibs.
carriage feed	2.	Gib screws are too tight.	2.	Loosen gib screw(s) slightly, and lubricate bedways
handwheel is hard				(see Page 75).
to move.	3.	Backlash setting too tight (cross	3.	Slightly loosen backlash setting (see Page 75).
		slide only).
	4.	Bedways are dry.	4.	Lubricate bedways and handles.
Cutting tool	1.	Tool holder not tight enough.	1.	Check for debris, clean, and retighten.
or machine	2.	Cutting tool sticks too far out of tool	2.	Re-install cutting tool so no more than 1⁄3 of the total
components vibrate		holder; lack of support.		length is sticking out of tool holder.
excessively during	3.	Gibs are out of adjustment.	3.	Adjust gib screws at affected component (see Page
cutting.				75)
	4.	Dull cutting tool.	4.	Replace or resharpen cutting tool.
	5.	Incorrect spindle speed or feed rate.	5.	Use the recommended spindle speed.

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