QUALITY AND RELIABILITY ANALYSIS OF LATHE MACHINE MECHANICAL WORKSHOP STATE POLYTECHNIC OF MEDAN THROUGH STATIC GEOMETRC TEST ACCORDING TO ISO 1708 STANDARD

Abstract

The purpose of this study was to determine the condition and
accuracy of the lathe through static geometric tests according to ISO-
1708 standards. The tests include measuring the level of the machine
base, sloping straightness towards the horizontal plane, alignment of
the motion of the loosehead in the horizontal and vertical planes,
accuracy of the main axis, alignment of the supporting shaft launchers
to the movement of the nose spindle irregularities, alignment of the
nose spindles and alignment of the main axes in horizontal and vertical
directions. Tests are carried out by measuring the quality and reliability
of the machine to find out how many accuracy deviations that occur in
the main part of the lathe. Quality measurements using a precise
measuring instrument that is the spirit level, dial indicator, micrometer,
and supporting flashlight and mandrel shaft. The results achieved from
this study indicate that the condition-, and the quality of the lathe
Maximat V13 and the Celtic I4 lathe at the mechanical workshop have
decreased. Only 50% of machines can still be operated. The
components contained in each engine have been damaged and
incomplete. For the number of 7 Maximat V13 lathes, the condition is
not optimal, only 3 units of the machine still operate and its reliability
has decreased. The results of the inspection of the main parts such as
the fixed head, speed control lever, speed control lever, screw
movement control lever, machine base, and longitudinal slides are still
good but the other parts are damaged and incomplete. For the number
of 6 Celtic14 lathe units, 3 machines were still in operation and the
engine components were still complete while 3 other machines were
damaged and incomplete. This machine condition will affect the
quality of the products and the time of machining process practices and
for producing precision products.