User Guide

replace the mounting plate, pivot the speed control back down and refasten it. Moving the
belt back to the other position is simply a reverse of the above procedure.
Preload adjustment
SPINDLE ADJUSTMENT-If any end play develops in the main spindle, it can be easily
eliminated by readjusting the preload nut. (See part number 4016 in the exploded view.)
When the headstocks are assembled at the factory, the preload nut is adjusted to .0002"
(.005mm) of end play. This is controlled by the outer races of the bearing being held
apart by the headstock case and the inner races being pulled together by the preload nut.
This setting was determined through experience and, like everything in engineering, it is
a compromise. If the machine is only to be run at high speed, this setting may be too
"tight". The headstock will run fairly warm to the touch normally, but extended periods
of high speed operation may bring about excessive temperature. If this is your case, the
preload may be reduced slightly.
To change the adjustment, remove the spindle pulley, loosen the set screw in the preload
nut and back the preload nut off four degrees of rotation (counter clockwise). The
bearings are lightly pressed into the case, so the inner race will not move without a sharp
tap with a plastic mallet to the end of the spindle where the pulley is attached.
If you find your bearings are set too loose, you may want to take up on the end play. You
can check them with an indicator or by spinning the spindle without the motor belt
engaged. If the spindle spins freely with a chuck or faceplate on it, it is too loose for
normal work. Adjust the preload nut until it turns approximately one and a half
revolutions when spun by hand.
Gib adjustment
Gibs (tapered synthetic adjustment shims) are fitted to the mill headstock, saddle and
table and to the lathe saddle and crosslide. Correct adjustment of the gibs will ensure
smooth and steady operation of the slides. The gib is effectively a taper with an angle
corresponding to the one machined into the saddle. It is held in place by an "L" wire gib
lock which is secured with a locking screw. It is adjusted by loosening the gib locking
screw and pushing the gib in until "play" is removed. After adjusting, retighten the
locking screw. Milling operations require a tighter adjustment of the gibs than lathe
operations.
Backlash adjustment
Backlash is the amount the handwheel can turn before the slide starts to move when
changing directions. This is a fact of life on any machine tool and on machines of this
type it should be about .003" to .005" (.08mm to .12mm).