LINK Systems System 1100 Tonnage Monitor - Manual (Page 101)

USING SYSTEM 1100 TONNAGE MONITORS
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tonnage near the least value that produces a correct part.
3) After correct setup is finished, use the Auto Setup function
to calculate and set all high, low, reverse tonnage setpoint
limits to a preset tolerance around the measured tonnage.
The Auto Setup tolerance can be increased and the Auto Setup
function executed again if nuisance stops due to normal
variations in production tonnage occur.
9.3.2 Sample Operator Instructions
The recommended operator instructions for an intermediate load
monitoring are the same as those for comprehensive load monitoring.
9.4 Diagnostic Uses
The System 1100 can help identify problems with machine or tooling
and can help refine die design to reduce required tonnage or
snapthrough tonnage, particularly when a recording instrument
(strip chart recorder or oscilloscope) is connected to the
"RECORDER" terminals, or a personal computer is connected to the
RS-232 port, to show the complete signal waveforms produced by each
strain link.
Pen and ink recorders such as the Gould 220 may be used for
observation of forming and drawing operations on presses operating
at lower speeds, however, the speed of response of such recorders
is generally not sufficient to accurately show waveforms for
blanking and piercing operations even on slower speed machines.
Rates of change of actual tonnage signals will be slowed and peak
values will be lessened. A storage oscilloscope connected to the
recorder terminals, or a personal computer connected to the RS-232
port is necessary to accurately show the tonnage signal.
9.4.1 Incorrect Tie Rod Tension
A common problem that occurs on straight side presses of tie rod
construction is improper tie rod tension. Such machines are
designed for tie rods to be in tension such that the bed and crown
of the machine are held to the uprights (columns) with a force of
from 150% to 200% of rated machine tonnage. The tension forces in
the tie rods produce equal compression forces in the uprights.
When strain links are mounted on uprights, the tonnage exerted by