PlaneWave L-350, Mechanical Installation Manual, Page: 17 / 32

17
Hole pattern and pier-interface advice:
In drawing to the right, the interface pattern is
described as a 12” bolt circle, with 60-degree
separation between holes. These holes should
be tapped through with 3/8-16 threads. The
mounting surface should be oriented so that
North/South align at the midpoint between
holes in the pattern, and so that there are bolt-
holes directly aligning to East and West.
The interface between the pier and drive-base
(or equatorial wedge, using the same pattern)
should follow one of two approaches:
1) Metal piers or extensions should
have their top-plates machined so as to offer
threaded-holes that correspond to the drive-
base’s hole-pattern.
2) Concrete piers should use an inter -
mediary interface-plate. This plate will have
threaded-holes matching the drive-base’s
hole-pattern, and then a secondary pattern
meant to accept the anchor-bolts placed in the
concrete.
While it is possible to place the anchors in
the concrete so as to match the drive-base’s
hole-pattern (offering threaded rod that would
pass through the lower-flange of the drive-
base’s perimeter), the tolerances involved will
make this difficult and mistakes will be difficult
to fix.
The top-plate of the metal-pier or inter -
face-plate mounted to the concrete-pier needs
to be level while firmly secured to the retain -
ing-bolts in the concrete. This should not occur
through stacking washers, as increased separa -
tion of these contact surfaces risks loss of the
rigidity your pier-anchoring should provide.