Fischer's Monitoring System SmartVision - Fischer Precise

Author: Rudolf Walter, Fischer Precise Deutschland GmbH
Fischer’s Monitoring System
SmartVision
Among others, monitoring is a significant and successful
tool to increase and maintain machine availability.
Numerous components can be monitored in a machine
tool, like slides, axis drives, pumps, pneumatic or
hydraulic cylinders, tool changer, doors, etc. However,
the main spindle unit is probably the core element of
a milling machine. Therefore, the main spindle unit is
the key element when it comes to machine or process
monitoring.
In the following Fischer’s Monitoring
System, SmartVision, is explained
and examples of its successful use are
presented.
Features
SmartVision uses several sensor signals
to monitor the spindle or the milling
process. These signals are:
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As an option, an axial displacement
sensor can be used, so called DMD
(Displacement Measuring Device), to
measure the axial growth of a spindle
shaft relatively to the spindle housing.
These signals are used to monitor the
following conditions:
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Bearing temperatures
Ambient temperature
Motor temperature
Motor current and speed
Vibration (velocity or acceleration)
Number of tool changes
Operating hours
Process stability
Spindle and tool balance
Crash
Stress profile (speed, number of
tool changes)
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Malfunction of the bearing
lubrication or cooling system
Improper converter parameter
settings
In order to be able to monitor these
conditions, limits have to be set prior to
operation. For the most cases, Fischer
has obtained data and derived suitable
limits.
Output
As an output, SmartVision generates
histograms (in percent of the pre–
set maximum value) for the signals
measured (figure1) that provide
important information about the
stresses a spindle has to endure.
Additionally, the last hour of the
operation is continuously monitored
(figure 2). When the pre–set limits
are exceeded, an error message is
generated and filed.
Online Monitoring
The error message and an
online–access are options that help
Fischer in cooperation with the machine
user to work on manufacturing or
spindles issues via the internet or
telephone.

A SmartVision set–up that offers this
option displays.
Case Study
Due to heavily unbalanced tooling (as
we know today), several premature
spindle failures occurred at a German
end user that manufactures aircraft
parts. Spindles used achieved a total
life of only 50 up to 250 hours. The
machine was used in a three–shift
operation, seven days a week. The
failures caused critical delivery
reliability and generated one month
Figure 1. SmartVision histograms (for example for
vibration).
production backlog. When a spindle
failure occurred, parts machined were
scrapped.
Then end user’s decision was to invest
into SmartVision to monitor the
process conditions. By post processing
the SmartVision data, all found out
that vibrations up to 9,5 mm/s (RMS)
overstrained the spindles and their
components (figure 3).
According to the spindle manual,
vibrations up to 4 mm/s (RMS) can be
Figure 2. Last hour of operation (for example for vibration). Figure 5. Vibration profile after implementing the corrective
actions.
FISCHER AG Präzisionsspindeln
P.O. Box 31
3360 Herzogenbuchsee
Switzerland
T +41 62 956 22 22
F +41 62 956 22 00
fch@fischerprecise.ch
PRECISE Präzisionsspindeln GmbH
Am Wallgraben 2
42799 Leichlingen
Germany
T +49 2175 971 0
F +49 2175 971 99
pd@fischerprecise.de
Figure 3. Analysis of vibration values measured
© FISCHER PRECISE GROUP • 2st Edition, 9/2008 • E 00 Copies
ARTWORK AND PREPRESS: FISCHER PRECISE GROUP • TEXT: Rudolf Walter, FISCHER PRECISE Deutschland GmbH • PRINTED BY: Lüthi–Druck AG, www.luethi–druck.ch
tolerated without negatively influencing
life of oil–air lubricated spindles.
The error messages and their time
stamps (figure 4) then were used
to identify critical tools and identify
corrective actions. As a result the
vibration profile has been decreased
successfully (figure 5) and a major
productivity improve has been
achieved. Spindle life was increased up
to 6800 hours.
Figure 4. Example of error messages.
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