IEMCA MASTER 880-VERSO P, Manual For Use And Maintenance

Page: 133 / 232

6 - USE AND OPERATION MASTER 880/880r VERSO
EN
6 - Pag. 13 / 23
6.6.1 BAR STRAIGHTNESS - Measurement
The bar vibrations are partially due to the state of the bar itself: if the bar is not perfectly
straight, it can cause vibrations.
Round bars
As stated also in the UNI-10233/2 regulation, the
bar straightness can be measured by positioning
the bar on two V-supports and controlling its
straightness. In that case, the measurement can
be carried out as shown in the figure.
It is necessary to rotate the bar on itself and
measure the three indicated sections. In this
case, the S-max value (difference between
maximum and minimum value on the comparator) should be interpreted as follows:
S max Quality
< 0,25 mm Good
0,25 < S max < 0,5 mm Average
> 0,5 mm Problematic
In order to obtain a reliable value it is necessary to repeat the measurements on the whole bar
length, by positioning it on a series of supports at a distance of 500 mm from each other and
comparing the values registered between the different prisms.
INFORMATION:
The bar straightness is obviously proportional to the rigidity of the material and
to the number of revolutions (RPM) to which the lathe must operate. The lack of
bar straightness highly influences the maximum number of revolutions that may
be reached: the bigger the diameter the greater the influence. The data
concerning the bar linearity or straightness refer to the bar constant bending
and not to the localized inflection and/or deformation that the bar shall not
absolutely show.
INFORMATION:
For a correct operation of the bar feeder do not use rolled material.