ACCU-Pro 670, Assembly And Service Manual

Page: 33 / 52

33
TROUBLESHOOTING (Continued) BEDKNIFE GRINDING
--POSSIBLE CAUSE-- --REASON-- --PROBLEM--
Top face of
bedknife is
ground in a
convex shape
(high in the
center)
A--Grinding wheel loading up
with grinding grit.
B--Too heavy a grind on the
final grinding pass.
C--Carriage has varying load in
either direction, because of grit
buildup inside linear bearings.
D--Rails not straight.
A loaded wheel creates
undue pressure on the
surface being ground. Both
ends of bedknife move
because of this pressure,
allowing bedknife to rock on
the middle support.
For precise grinding, spark-
ing-out process is critical. It
eliminates excessive final-
grinding pressure on centers
and middle support, which
helps maintain grinding
straightness.
Uneven loading because of
grit buildup in bearings can
affect the straightness of
grinding. When grit buildup
is excessive, bearings may
be noisy and must be
replaced.
Straightness of rails is
critical for accuracy of
grinding.
Dress the wheel prescribed in
the Operators Manual.
Follow the procedures in the
Operators Manual. On the
final pass, adjust only about
.001" [.025 mm]. Let the wheel
spark out for 10-20 passes at
about 5 ft/min, with no addi-
tional infeed.
With linear actuator released
from the carriage, check for a
3lb [1.63 kg] maximum travers-
ing load in both directions. If
load varies, or carriage linear
bearings are excessively noisy,
replace bearings See Page 19).
Check straightness. If not
straight, consult the factory
through your distributor. (This
is carefully checked at the
factory, so it is unlikely to be
the cause.)
--REMEDY--