Yamato SB125 Instruction Manual page 11

fig. 2
WATER GRINDING WHEELS: These wheels are mainly used to work and sharpen knives, chisels,
shears and other cutting tools. To sharpen these tools, place the cutting implement on the
wheel, if necessary using the tank's serrated steps (n. 4, fig. 5) to set the correct angle.
While sharpening, ensure the water level is such as to keep the wheel wet at all times. This
prevents the tool from overheating.
When the item has been sharpened, empty the tank by removing the rubber cap (fig. 5, n. 5).
To dress the grinding wheel and prevent it from becoming oval, press a hardened steel bar
gradually against the moving wheel.
WARNING! With any grinder, it is always important to comply with the instructions of intermittent
use (S ) specified on the machine's plate, bearing in mind that in general these machines can
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run continuously for at most 10 min.
At this point, it is important to switch the machine off and wait for the electrical motor to cool
down sufficiently before resuming operation.
8. CHARACTERISTICS AND WHEEL REPLACEMENT
The grinding wheels provided are ceramic bound. Their grain size varies, depending on the
model of the machine and the size of the wheel (see table on page 1). In the event of
replacement, always use wheels with the same characteristics and bearing the following
information:
- name of manufacturer
- type of binding material
- size
- max. n. of revolutions
Bear in mind that the speed indicated on the wheel must be greater than that indicated on the
machine's technical data plate.
FORMULA FOR CALCULATING THE PERIPHERAL SPEED:
(n. revolutions/min X external wheel diam. in metres X ∏) / 60 = m/sec
E.g. (2,950 X 0.15 X 3.14) / 60 = 23.15 m/sec
WARNING! Remember to unplug the power cable before carrying out control or maintenance
operations on the machine.
REPLACING AN EMERY GRINDING WHEEL
Loosen the fixing screws found on the protective lid (letter "a" in fig. 2), then remove the lid.
Use a spanner to loosen the flange's fixing nut, turning anti-clockwise and keeping the wheel
blocked.
Remove the used wheel and replace it with a new one, remounting all the pieces removed in
the inverse sequence and fixing the screws and nut securely.
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