On an NC/CNC machine tool, ballscrews replace leadscrews
, motors replace hand wheels, and an electronic numerical controller performs many of the functions formerly carried out by the machinist.
Because this indicator measures the relative displacement between the fixed and moving sections of the slide, counting turns is unnecessary as is the need to compensate for leadscrew
error or backlash.
Hydrostatic design has taken a major leap forward as an alternative to traditional slide and roller systems used in guideways, as well as for leadscrews
, spindles, and bearings.
A ball screw comprises the leadscrew
itself and a ball nut that is fitted onto the screw.
In the case of the HRP 201 machine, the overhaul included repair of the handwheel, leadscrew
, and worktank, replacement of the mechanical stops, and replacement of the original 12" travel Z-axis with a 16", programmable, high-resolution (0.
taps are unrelieved (circular) so that, beyond the cutting chamfer, the rest of the thread form has no cutting flutes and acts like a leadscrew
, driving the fluted cutting end through the hole.
The carriage is equipped with an overload protection device using a slip-cone clutch that protects the gears, feed rod, and leadscrew
in the event of an overload.
This movement, along with the leadscrew
longitudinal feed, is accurately measured on 8"-dia handwheels with graduated slip rings, and on the optional DRO.
This innovative design includes a precise leadscrew
driven by a miniature geared motor, a displacement sensor, an optical sensor and an optional force sensor.
Problems arising when a half nut is worn, and resultant failure to engage fully with a leadscrew
, have been reported on the Graseby 3500 TCI pump (1).
Featuring a Teflon-coated leadscrew
drive with a proprietary coupling system stage repeatability is better than 2 microns.
The complete machine is fully adjustable via leadscrew
with digital reference counters and without changeparts, sot hat size changes can be achieved in under 15 minutes, and the option of automatic size change reduces this still further.