Alpha Tool.Com.HK Limited Grinder ECG125 User Manual

							21
3.  Using small needle nose pliers, gently pull the carbon brush holder stra\
ight out from 
the motor housing. After removing the carbon brush holder from the motor housing, 
you need to remove the power wire terminal from the carbon brush holder \
(Note: the 
path of the wire, as it is important for reassembly of the unit).  The carbon brush holder 
assembly is now free from the machine and can be inspected.
 
4.  Pictured on the left below, is a worn carbon brush in the holder (Note: the twisted wire 
is	at	 the	 end	 of	the	 slot	 and	 the	carbon	 brush	is	almost	 flush	with	holder).		 On	the	 right 	
below, is a new carbon brush in the holder.
NOTE: Carbon brushes sometime wear at different rates; however, both carbon brushes 
should be replaced at the same time.  The carbon brushes in this grinder are located 
under the rear handle.
  
  WARNING!
Replacing the carbon brushes in this unit with non-Alpha® parts could damage the unit, 
and will void the warranty.
Power Wire and Terminal
Figure-15
Figure-16
Carbon Brush Removal
Worn and New Carbon Brushes
WornNew  
						

							22
5.  The carbon brush can be removed from the holder by pulling back the carbon brush 
spring and moving it to the side as shown in the photo on the left below\
.  After reas-
sembly, press the carbon brush in and out of the holder to make sure it moves freely and 
the twisted wire is not hitting the wire terminal or spring (see photo \
below on right).
 
6.  Remove the old carbon brush and disconnect the wire terminal. If the ins\
ide of the 
holder	 is	filled	 with	dust,	 clean	 it	before	 installing	 the	new	 carbon	 brush.		Upon	instal-
lation of the new carbon brush, make sure the twisted wire is in the slo\
t and behind 
wire terminals on the holder (as in the above right photo).
7.  With the carbon brush holder removed, you can check and clean the armatur\
e com-
mutator.  The commutator is the contact points that the carbon brushes ride on when 
the motor is running.
8.  The commutator should be clean and shiny. If it is dull and black, you can clean it with 
a commutator cleaning stone.
  
Figure-17
Figure-18Figure-19
Carbon Brush
Spring
Twisted Wire
CleanDirty
Clean and Dirty Commutator
Removing and Installing the Carbon Brush 
						

							23
9.  To clean the commutator, press the commutator cleaning stone against the commutator 
and rotate the armature by turning the spindle shaft by hand. Continue for a minute 
or until the commutator is clean and shiny.
10.	 Reconnect	 the	power 	wire,	 insuring	 that	the	 wire	 path	 is	correct	 (See	figure	 15),	Re-
install the carbon brush holder into the slot on the motor housing and slide in until the 
screw tab hits the stop, then install the screw using light pressure to prevent it from 
stripping.
Note: All electric tools have two carbon brushes located on opposite sides of the tool. Turn 
the tool over and replace the carbon brush on the other side following steps 2-10 
again.
11. After both carbon brushes have been replaced, you can reassemble the rear handle 
assembly.	 The	switch	 side	should	 be	installed	 first.		Make	 sure	the	power	 wires	are	in	
the slot above the soft starter assembly and the soft starter assembly is in its holder 
to prevent the pinching of the wire.
12.  Hand-tighten the four self-tapping screws in the handle to prevent them from stripping 
(see	figure	13).
13.  With the tool reassembled, perform the daily maintenance and run the tool\
 in a no-load 
condition for a couple of minutes to re-seat the carbon brushes.
Wire slot
Soft Starter 
Assembly
Figure-20
Figure-21
Cleaning the Commutator
Reassembling the Handle   
						

							GRINDING WHEEL INSPECTION, REMOVAL, AND 
INSTALLATION
 
  DANGER!
Be sure to unplug the power cord from the outlet before attaching or removing the grinding 
wheel from the tool.  Accidental starting of the motor may cause bodily injury.
 
  WARNING!
Be	sure	 to	securely	 tighten	the	flange	 assembly	 and	all	loose	 screws	 before	testing	 the	unit. 		
Please allow the grinding wheel to do the work.  It is not necessary to \
apply more force onto 
the machine than the force created by the weight of the machine itself.   Applying excessive 
force may damage the grinding wheel and cause premature failure of the b\
earings and 
gears.  Such action may decrease the rotation speed of the of the motor \
which reduces the 
efficiency	of	the	dust	suction,	because	its	power	is	driven	by	the	spindle.
  INSPECTING THE GRINDING WHEEL
1.  If you are reinstalling the grinding wheel, check the welds on the diamond segments 
for cracks.
2.  Check the diamond segments for even wear.
3.	 The	 grinding	wheel	should	 be	replaced 	if 	you	 find	a	 crack	 in	the	 weld 	or 	if 	the	 diamond 	
segments are worn down and below the brush assembly.
 
NOTE: The Alpha®	26mm	 arbor	grinding	 wheel,	drive	plate	adapter	 and	spring	 loaded	 flange	
assembly are designed and engineered to work together.  This design eliminates the 
need for adjusting the grinding wheel height as the diamond segments wea\
r.
Diamond
Segment
Wheel
Drive Plate 
Adapter 
Figure-22
26mm Arbor Grinding Wheel w/ Drive Plate Adapter Attached
24 
						

							   CHECKING THE GRINDING WHEEL FOR REPLACEMENT
1.	 The	grinding	wheel	and	spring	 loaded	 flange	are	designed	 to	be	 self-adjusting.		 The	
grinding 	wheel	 should 	float 	on 	the	 flange	 nut	allowing	 it	to 	adjust 	to 	the	 height 	of 	the 	
brush assembly.
2.  The grinding wheel should be replaced when the diamond segments are worn down 
close to the hub and there are no visible diamond chips.
3.  You also need to check the grinding wheel and diamond segments for chips, cracks 
in the welds, or missing segments.
4.  Continuing to use the grinding wheel when it is in need of replacement w\
ill prematurely 
wear	out	the	brush	assembly	and	the	system	will	not	work	efficiently.
   
 
 
  DANGER!
Do not use a grinding wheel that is chipped, cracked or missing diamond segments.
Diamond Segments
Welds
Figure-23Figure-24
Checking the Grinding Wheel Diamond Segments
25 
						

							26
Figure-25
Figure-26
Spindle Lock Button
Loosening the Flange Bolt
  REMOVING THE GRINDING WHEEL
1.  While pressing in on the spindle lock button, turn the grinding wheel by hand until the 
lock can fully engage.
 
2.	 With	 the	lock	 fully	 engaged,	 turn	the	flange	 bolt	counter	 clockwise	 to	loosen	 the	flange 	
bolt	with	the	flange	wrench.
 
3.	 If	 the	grinding	 wheel	is	turning	 during	removal,	 then	the	flange	 nut	is	unscrewing	 off	the 	
spindle.	 Remove	 the	complete	 flange	assembly.		 With	the	flange	 assembly	 removed	
use	a	24mm 	or 	adjustable	 wrench	and	 the	flange	 wrench 	to 	remove	 the	flange	 bolt	
from	the	flange	nut.   
						

							27
  REPLACING THE GRINDING WHEEL
1. To replace the grinding wheel follow the steps for removing the grinding wheel (see 
page	26).		After	 the	grinding	 wheel	is	removed,	 you	need	 to	remove	 the	three	 flat-head 	
screws holding the drive plate adapter onto the diamond grinding wheel.
Note: When you purchase a replacement Grinding Wheel (Part # DSQ0500), it does not come 
with the  Drive Plate Adapter (Part # 801381) or Flat Head Screws (Part # 801382).  
These parts need to be ordered separately or re-used if still in good co\
ndition.
 
2.	 Clean	 the	inside	 of	the	 Drive	 Plate	Adapter	 and	check	 for	wear.		 If	the	 square	 arbor	is	
worn, 	it 	will	 prevent 	the	 grinding 	wheel	 from	floating	 on	the	 flange	 nut,	and	should	 be	
replaced.
3.  Place the Drive Plate Adapter onto the new Diamond Grinding Wheel and align the 
holes.  A small drop of Loctite thread lock should be applied to each screw to ke\
ep it 
from loosening. Tighten each screw until seated, then go back around and re-tighten 
each screw to secure them evenly.
4.  The new Diamond Grinding Wheel can now be reinstalled on the tool.
Grinding wheel, adapter and screws
Figure-27Drive Plate
Adapter
Grinding Wheel 
(26mm Arbor)Flat Head Screws
(M4x6)   
						

							28
  INSTALLING THE SPRING LOADED FLANGE ASSEMBLY
NOTE:	This	unit	comes	 equipped	 with	a	self-adjusting	 spring	loaded	 flange	assembly.		 This	
flange	 assembly	 allows	the	grinding	 wheel	to	adjust	 as	it	wears	 to	keep	 positive	 contact	
with the work.
1.	 With	 the	inner	 fan	belt	 and	 cover	 installed,	 you	can	now	 install	 the	spring	 loaded	 flange	
and grinding wheel.
2. Install the lower spring retainer, spring, and upper spring retainer.
  
Note: The Spring Loaded Flange Assembly only works with the 26mm arbor grinding wheel 
(DSQ0500) and the drive plate adapter.  A 7/8” round hole arbor will just spin on 
the	flange	nut.
Flange Nut
Lower Spring 
Retainer
Upper Spring Retainer
Spring
Figure-28Figure-29
Spring Loaded Flange Assembly   
						

							29
Flange Bolt
Grinding 
Wheel
Figure-30
Figure-31
Figure-32
Grinding Wheel and Flange Bolt
Spindle Lock Button
Tighten the Flange Bolt
  INSTALLING THE GRINDING WHEEL
1.	 Place	the	grinding	wheel	and	flange	bolt	on	the	spindle.
 2. While pressing in on the spindle 
lock button, turn the grinding wheel 
by hand until the lock is fully en-
gaged.
3.  With the lock fully engaged, turn the 
flange	 bolt	clockwise	 to	tighten	 with	
the	flange	wrench.
 
4.	 With	 the	flange	 bolt	and	nut		tightened,	 check	and	make	 sure	the	grinding	 wheel	moves 	
freely	up	and	down	on	the	flange	nut.
 
5. Plug the unit in and test run to check for balancing before starting to \
grind.  
						

							30
FAN BELT REMOVAL AND REPLACEMENT
The Ecogrinder incorporates two drive fan belts (an inner and an outer)\
 to power the fan 
assembly.  If the unit is not removing the dust, you will need to inspect the fa\
n belts, fan 
assembly,	and	dust	bag	to	find	the	cause	of	the	problem.
NOTE:	This	Ecogrinder	 makes	use	of	a	flat	 fan	belt	 and	 pulley	 system	 that	is	self-centering 	
due to the barrel shape of the pulleys.  If the fan belt is worn or dirty it can rotate\
 off 
the pulleys, this will be indicated by a loss of suction.
  TESTING THE UNIT FOR FLOW
1. A simple test can be done to see if the fan unit is working correctly.
2.	 Disconnect	 the	hose	 and	back-flow	 preventer	from	the	tool	 and	stand	 the	grinder	 up	
so it is resting on the protective housing and the top handle. Point the\
 fan exhaust in 
a direction away from you or anyone else.
3.  Turn the unit on and hold a piece of paper over the exhaust port. Paper s\
hould extend 
and stand up straight when unit is turned on.
 .. 
4.	 If	 the	test	 indicates	 a	weak	 or	no	 flow	 condition,	 the	fan	belts,	 pulleys,	 and	fan	unit	 will	
need	to	be	checked	to	find	the	cause	of	the	problem.
Figure-33Figure-34
Fan Unit Test
OFFON