-49-
Model M1112 (For Machines Mfd. Since 12/20)
SE
RV
IC
E
12.
Without causing the inner spanner nut to
tighten any further, install and tighten the
outer spanner nut against the inner nut.
Do not overtighten the outer spanner nut
because additional preload can force the
bearings even tighter against the races in
the headstock and cause the headstock to
compress, crack, or cause bearing failure.
13.
Position the gasket correctly, and re-install
the outboard spindle cover.
To confirm that the bearings are correctly
preloaded, do these steps:
1.
Make sure all safety precautions have been
taken and set up steps are complete to make
the lathe fully operational.
2.
Install the chuck and tighten the jaws.
3.
Set the spindle speed to its highest setting.
4.
Connect the lathe to power and turn the
lathe spindle
ON
.
5.
Let the lathe run for 20 minutes.
6.
Turn the spindle
OFF
, disconnect lathe
from power, and check the temperature of
the spindle.
— If the spindle nose is slightly warm to the
touch, you have correct bearing preload.
— If the spindle nose is hotter than you
can comfortably keep your hand on, the
preload is too tight and you must repeat
bearing preload adjustment procedure.