LINK Systems System 1100 Tonnage Monitor - Manual (Page 51)

4-1
4.1 Selection of Automatic Zeroing Method
As explained in the Section 3 of this manual, two methods of
automatic zeroing are possible with a System 1100 Tonnage Monitor.
The rate of change method of automatic zeroing requires less
hardware (no cam switch or limit switch) and less installation
wiring and is excellent for most non-geared mechanical power
presses, hydraulic presses, and similar machines. Each System
1100 shipped from the factory is set up for standard rate of change
zeroing.
Although rate of change zeroing often works well on some large gear
driven machines, a significant number of such machines experience
strains in the machine frame large enough to induce small load
readings on the System 1100 tonnage display due to forces
introduced by gear slap, clutch engagement, and/or brake engagement
acceleration characteristics. It is recommended that zeroing by
position (cam zeroing) be used on large gear driven machines. Some
smaller non-geared machines with high clutch or brake torque may
also significantly strain the machine frame and produce unwanted
tonnage readings due to clutch or brake engagement.
If rate-of-change zeroing is used, follow the checkout procedures
outlined in Section 7 to confirm that no nuisance readings due to
mechanical "noise" interfere with desired tonnage readings.
4.2 Strain Link Mounting Locations
4.2.1 "C" Frame Machines
Machines with "C" frame configurations, such as OBI and GAP frame
presses, OBS hydraulic presses, etc., are best monitored with two
strain links input to a two channel System 1100 Tonnage Monitor.
One strain link should be mounted on each sideframe member.
This monitoring method indicates total tonnage as well as load
distribution to both sides of the machine frame. It also indicates
when excessive stress is placed on the machine by tooling that is
located forward of the pitman(s) or other connection(s) to the
machine slide. Choices of strain link mounting locations are
illustrated in Figure 11.
Section 4. Applications Information