Maintenance; Troubleshooting - KNOVA KN CM-11MA Manual

MAINTENANCE

WARNING
Turn the planer off and unplug from the power source
before proceeding to do any maintenance work.
CHECKING FOR WORN BLADES
Condition of blades will affect precision of cut. If blade wear
is not observed when checking the blade height, the quality
of cut will indicate the blade condition, dull blades will tear
rather than sever wood fiber. A raised grain will occur when
dull blades pound on wood where there is a difference in
density. A raised ridge will be produced where the blades
have been nicked.
SHARPENING BLADES
If blades are nicked they must be replaced or reground, they
can be reground several times until they become 21 mm side.
NOTE: many shops do not have capabilities to resurface
blades. Never install unbalance blades or blades reground
less than 21 mm wide.
38º
21 mm wide
REPLACING BLADES
Unplug the planer from power source, block the blade guard
from closing, loosen and remove the four blade lock screws
securing the blade and blade clamp, lift blade and blade clamp
from cutter head, clean any sawdust and resin buildup from
cutter head and blade clamp, place the new blade against
the blade clamp and replace in cutter head. Secure blade and

TROUBLESHOOTING

SYMPTOM POSSIBLE CAUSE(S)
Motor does 1. Defective switch.
not start.
2. Defective motor.
3. Low line voltage.
Motor starts 1. Defective motor windings.
slowly or fails to
2. Clogged wood chips.
come to full speed.
Motor running 1. Motor overloaded.
too hot.
2. Restricted air circulation
Snipe (gouging 1. Dull blades.
at end of boards).
2. Inadequate support of long boards.
3. Uneven feed.
due to dust accumulation.
blade clamp using the four blade lock screws, do not tighten
the blade lock screws until you have checked the blade height,
adjust as required using straight edge as described in
"adjusting blade height". Tighten blade lock screws, recheck
blade adjustment and make sure blade is still level with out
feed table. Repeat procedure to replace the other blade,
remove the scrap wood release blade guard.
Cutterhead
Blade lock
screw
BRUSH INSPECTION AND REPLACEMENT
Turn planer off and disconnect from power source. Brush
life depends on amount of load on motor. Regularly
inspect brushes after 50 hours of use.
To inspect or replace brushes, remove the bottom cover and
disassemble the motor, loosen brush cap and remove it from
motor, replace bushes if springs are worn or carbon is worn
down to 10mm in length or less.
NOTE: Replace brushes in sets only.
Replace brushes and tighten brush cap, replace bottom
cover and the screws.
CORRECTIVE ACTION
1. Have switch replaced.
2. Have motor replaced/repaired.
3. Correct low line voltage condition.
1. Have motor replaced/repaired.
2. Make a shallower cut and attach a dust collection
device to the exhaust port. Inspect chip blower
assembly and fan belt.
1. Reduce load on motor.
2. Clean dust and restore normal air circulation.
1. Replace or sharpen blades.
2. Support long boards.
3. Feed the workpiece at a consistent rate.
8
Jack screw
Blade
Blade
clamp