LINK Systems OmniLink 5000 - Manual (Page 62)

April 17, 2000 Man ual Revisio n 1.0
7.7
Figure 7.6: Drill Fixture
Figure 7.7: LST-1000 Strain Link
Note! Do not attempt to locate and drill
mounting holes without using the drill fixture.
The hole pattern must be precise.
Section 7.3 Strain Gauge Mounting
Strain gauges may be bolted directly to the machine or bolted to intermediate pads welded or adhered to
the machine.
Section 7.3.1 Direct Machine Mounting
1) Select the desired mounting locations for the strain gauges.
2) Remove paint, oil, grease, etc., to obtain a bare metal surface slightly larger than the LST-1000
strain gauge. The metal surface must be flat and smooth so that the strain gauge is not warped
and contacts the surface area evenly when mounted. A mounting surface that is flat to within
.0025 inches and with a 250 microinch or less finish will give best results. Grind the surface if
necessary.
3) Scribe a line on the metal surface on which the strain gauge is to be mounted in the direction of
tension or compression of the structural member. This will be a vertical line on columns or tie
rods of straight side presses and "C" frame machines that are not inclined. On inclined presses,
the scribe marks should follow the inclined angle.
4) Place the hardened drill fixture provided with the direct
mounting strain gauge kit in position adjacent to the
scribed line and use a no. 3 drill to drill a 5/8" deep
hold through the center hole position of the drill
fixture. Tap the hole for a 1/4 x 28 thread. Bolt the
drill fixture securely to the mounting area, as shown in
Figure 7.6.
5) Use a no. 3 drill to drill 5/8" deep holes in the
mounting surface through the remaining four holes in
the drill fixture. Tap the holes for a 1/4 x 28 thread
after removing the drill fixture.
6) Deburr the mounting holes and wipe the mounting area
with a clean rag.
7) Mount the strain gauge as shown in Figure 7.7. Make certain that the washers provided with the
strain gauge kit are placed over the strain gauges. Torque the 1/4 x 28 bolts to 150 in-lbs. A
calibrated torque wrench is the preferred tool to torque the bolts.
8) Mount the protective cover box provided in the strain gauge kit, if used, centrally over the strain
gauge. It is important to mount the cover box before calibration begins. The cover box