TM 5-3895-373-34
B.
REMOVE.
1.
SET SCREED THICKNESS CONTROLS AND
CROWN ADJUSTMENT TO NULL POSITION
WITH SCREED RAISED.
a.
Place cribbing beneath outer edges of
extension screed, but do not allow screed
to rest on cribbing.
b.
Set screed thickness controls to read the
same on indicators for both the left and
right side per TM 5-3895-373-10.
c.
Lower hinged steps on main screed. Refer
to TM 5-3895-373-10.
d.
Remove
thumbscrews
(6)
and
crown
adjustment wrench (7) from main screed.
e.
Use crown adjustment wrench to loosen
hex nut (8).
NOTE
The main screed plate has a positive
lead crown that cannot be nulled by
crown adjustment. Sized spacers
between main screed plate and main
screed frame on leading edge of main
screed hold the crown in position.
Only main screed plate trailing edge
crown
can
be
nulled
by
crown
adjustment.
f.
Determine if a crown is present by reading
crown pointer (9) on main screed. If no
crown is present, pointer will read zero.
g.
To null a positive crown on main screed
trailing edge, pull crown adjustment wrench
(7) down toward screed trailing edge until
crown pointer (9) reads approximately zero
and no resistance is felt on wrench.
h.
To null a negative crown on main screed
trailing
edge,
push
crown
adjustment
wrench (7) up toward screed leading edge
until crown pointer (9) reads approximately
zero and no resistance is felt on wrench.
i.
Place a straightedge along underside of
main screed trailing edge. Have a second
person turn crown adjustment until trailing
edge of main screed plate is flush with
straightedge.
j.
Tighten hex nut (8) on crown adjustment
with crown adjustment wrench (7).
k.
Replace crown adjustment wrench (7) on
main screed and secure with thumbscrews
(6).
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