Foredom K.1020 - Manual (Page 3)

6. Fuse Protection
The internal circuit is protected by a 3.15
Amp, 5mm x 20mm, Bussman Type
GDC-3.15A or equivalent fuse. A blown
fuse usually indicates a short circuit
condition on the circuit board.
The blown fuse should require that the
board be checked by a qualified technician.
Disconnect the power cord, unscrew the
four feet and remove the baseplate. The
fuse is located in the top left corner of the
circuit board. Replace fuse and reassemble
the baseplate with four feet. Re-connect
the power cord and test unit operation.
H.MH-120
Micro Grinder Handpiece
Changing Accessories:
Burs and other accessories can be inserted
or removed from the handpiece chuck
when the jaws are open. These handpieces
have a geared 3-jaw #0 chuck. To Open the
Chuck– Put the power switch on control
box in OFF position and wait for handpiece
to stop rotating.
If accessory does not run true, reopen jaws,
rotate accessory and retighten.
To release accessory, simply reopen chuck
jaws with key and pull out accessory.
Supplied with Micro Grinder
The K.1020 Micro Grinder Kit comes
supplied with a chuck key for changing
accessories, a spare pair of motor brushes,
and a spare fuse.
Maintenance
The H.MH-120 handpiece has perma-
nently lubricated ball bearings that do
not require lubrication. Putting even a
small amount of oil into the handpiece
can damage it.
Cleaning Handpiece:
Use the Handpiece in as clean and dust
free an environment as possible.
If the Micro Grinder Handpiece is used
for woodcarving, it should be cleaned
after every use. With handpiece power
cord disconnected from control box,
remove the two screws securing the pro-
tective cap (shown below) and use a clean
cloth to wipe dirt, chips or dust off from
the exhaust ports and inside the cap.
A cloth with a small amount of alcohol
solution can be used to clean the outside
of the handpiece if necessary. Do not use
any other cleaning fluids or immerse
handpiece in any liquid. The H.MH-120
Handpiece is not autoclaveable.
Open chuck
jaws as far
as necessary
with key
provided.
Insert shank
of accessory
fully into the
chuck.
Tighten each
of the jaws
with chuck
key until
accessory is
secure and
centered.
protective
cap
exhaust
ports
exhaust
ports
4-feet baseplate fuse
fuse motor brushes
chuck key
Figure 3
Checking/Changing
Carbon Brushes:
A spare set of motor brushes is supplied
with each handpiece. Depending on how
long the handpiece is used each day, the
brushes should be checked for wear period-
ically (about every 200 hours of use) and
replaced when the brush is less than
2.5mm (3/32
″) long.
1. With handpiece power cord disconnected
from control box, remove the two screws
securing the protective cap from rear of
motor (see Figure 10). Remove the
protective cap.
2. With small crosspoint screwdriver
remove screws and brush assemblies one
at a time when reusing existing brushes.
Check length of carbon brush from spring
to curved side of brush. Brushes should
be removed, and replaced if less than
2.5mm (3/32
″) long.
3. If new brushes are needed, Always
replace both motor brushes even if one
is less worn than the other.
4. Reinsert each brush assembly or new
brush assembly into brush tube. Place
cordset tab on top of brush assembly.
Replace and tighten screw.
5. Slide protective cap back onto rear
of motor housing so that top of brush
assembly is completely covered.
Tighten screws.
6. If new brushes are used, run the
handpiece for 30 minutes at half-speed
no load to confirm proper function,
then use.
pair of new
motor brushes
remove
screw
tighten
screw
protective
cap
new motor brush worn motor brush
tighten
screws on
protective
cap
when you
reinsert a
motor brush
the curve
should align
with the
handpiece
contour
If the motor brush is long enough to
continue using be sure that when you
reinsert a motor brush the curve aligns with
the contour of the outside of the housing
and the curve of the motor armature within.
brush
tube
motor
brush
assembly
motor
brush
cordset
tab
cordset
tab
screw