 Backlash
Elimination
Our unique Flexplates eliminate all
system backlash and pivot around the rack pitch line permitting as much
as 0.015 inch variation between the fixed and moving members without
affecting the measuring accuracy. Repeatability is within
0.000025" over the total length of travel.
Neutral
Axis Concept
The Rack Channel has been designed such
that neutral axes in bending intersect at the pitch line of the rack.
This theory has been proven in practice. The calibrated accuracy
of the rack assembly is not altered when it is mounted on a machine.
This can result in significant savings for machinery builders because
mounting surfaces need not be perfectly flat (+/-0.040" for +/-0.0001"
change in accuracy). Our tests have shown that normal bolted
joints between scales and mounting surfaces introduce distortion and
result in measuring signigicant local errors - particularly in high
resolution systems.
System
Accuracy
This is a non-contact system at the
point of converting a mechanical motion into an electronic position
signal. In any non-contacting measuring system a precision air gap
must be maintained between the moving member and the sensors. Our
air gap is within the rotating transducer and accurately maintained by
high quality bearings. It is easier to maintain closer tolerances
with instrument size components with small ABEC 7 ball bearings than a
large machine member with large bearings.
Total measuring accuracies within
0.0001 inch over most any length of travel are commonplace with either
open rack or protected rack channel; and accuracies within 0.0005" are
possible by use of laser calibration of special Grade 4 rack on a
machine combined with Quality 15 pinion shaft encoders or resolvers.
Repeatability
With Protected Rack Channel,
0.0001" bi-directional repeatability can be expected.
|
