C
HAPTER
4 - I
NSTALLATION
25
SL Lathe Head Stock Taper Specification
(Refer to this text while leveling the machine in the startup checklist)
Milltronics SL lathe products have a .0002 inch per foot specification for head stock
taper.
In almost all cases action will be required at the time of setup to adjust the lathe into
tolerance.
The first step in the process is to level the machine. The bed should be as level as
possible and should be checked for twist. Check for twist is laying a precision level
along the cross slide and moving the Z axis back and forth slowly, watching the bubble
for movement. If the lathe is to be bolted to the floor, level and twist must be checked
after the lathe is bolted down.
Checking for head stock taper can be done several ways.
By making a cut on a bar and measuring it for taper. This method works well and
is the easiest to set up. It does not require the stock be dialed in as the cut will
make it concentric. Quality of the cut and tooling pressure can have an effect on
the measurements, however, and need to be minimized for an accurate reading.
By inserting a ground bar into the chuck of the lathe and check along its length
with an indicator. The bar must be dialed in for concentricity to the spindle on
both ends before checking for taper. This may prove difficult with a three-jaw
chuck.
By inserting a ground bar into the spindle with the chuck removed. This requires
a bar that has the morse taper of the spindle ground into its end. Typically there
is a spindle taper adapter plug shipped with the machine to be used with a
center, and this taper can be used as well. Using the taper eliminates any need
for dialing in the bar, so long as the mounting taper is ground concentric with the
bar.
The tailstock should not be used when checking head stock taper.
If the lathe is level and taper exists, the headstock can be adjusted. This is done by
loosening the bolts holding the head stock to the frame of the machine and using the
adjuster found at the rear bottom edge of the head stock case. Adjust and recheck as
necessary.
