BAQ kaloMAX NT II
Manual
grinding path will be done automatically. The ball diameter must be entered. The
geometrical values of the device (distance between the supporting points, diameter of
the shaft at the supporting points) will automatically be taken into the calculation.
2.2 Grinding speed / ball or shaft revolutions per minute
The grinding speed (ball or shaft revolutions per minute) corresponds to the distance
which the surface of the ball covers. This also has a great influence on the resulting
wear coefficient.
For all tests on hard coatings, 60 revolutions of the ball per minute has been used by
the IST. This is equivalent to a grinding speed of 5.6 m/min.
2.3 Bearing strength
The bearing strength cannot be measured directly. It depends on the weight and
diameter of the ball, the blade angle of the specimen and the distance between
specimen and shaft.
Therefore it is recommended, to keep this values constant for a series of tests. The
surface of the specimen should parallel the top side of the vice so that the blade angle
is 60 °.
The distance between specimen and shaft can be adjusted by means of a gauge. Set
the gauge onto the ground plate and push it against the shaft. Then push the whole
vice with the clamped specimen against the inclined surface of the gauge from behind.
The gauge must contact the shaft at both sides. The surface of the specimen should
contact the inclined surface of the gauge. Thus, the blade angle can be controlled.
Given a ball diameter of 30mm, the bearing strength is 0.54N in this position. The
adjustment has to be executed very carefully, because even small variations can lead
to different wear coefficients.
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