GSC GS-76 User manual

End Mill Grinder
Operation Manual
Model : GS-76

RECYCLING
Do not dispose of electrical appliances as unsorted municipal waste, use separate collection
facilities.
Contact your local government for information regarding the collection systems available.
If electrical appliances are disposed of in landfills or dumps, hazardous substances can leak
into the groundwater and get into the food chain, damaging your health and well-being.
When replacing old appliances with new once, the retailer is legally obligated to take back
your old appliance for disposal at least for free of charge.

Index
I. Safety Instructions .................................................................................. 2
II. Intended Use ........................................................................................... 6
III. Machine Installation Instruction ............................................................. 6
IV. Machine Devices Introduction................................................................ 7
V. Dust Collection Adapter Assembly Steps ............................................... 8
VI. Choose of Grinding Wheel & Accessories & Collet .............................. 9
VII. Chuck Set Assembly Steps ..................................................................... 9
VIII. The use of the Positioning Shelf............................................................. 11
IX. The use of the Cutting Face Adjustment Device .................................... 12
X. 2 Flute End Mill Grinding Preparations ................................................. 13
XI. 2 Flute End Mill Grinding Process ......................................................... 14
XII. 3 Flute End Mill Grinding Preparations ................................................. 15
XIII. 3 Flute End Mill Grinding Process ......................................................... 16
XIV. 4 Flute End Mill Grinding Preparations ................................................. 17
XV. 4 Flute End Mill Grinding Process ......................................................... 18
XVI . Machine Maintenance and Clean............................................................ 19
XVII . Troubleshooting ...................................................................................... 20
1

I. Safety Instructions
All personnel working with the machine must be properly trained in its operation, and must follow
strictly on the operating instructions and procedures given in this and all associated manuals.
The machine may only be operated by persons who are authorized and trained.
The user of the machine must not remove, modify or obscure in any way the content or the
readability of any safety label placed on or inside the machine.
The sound pressure level of this machine is less 70dB(A) with uncertainty 3dB.
The vibration total value does not exceed 2.5 m/s2.
WARNING
Read all safety warnings, instructions provided with this power tool. Failure to follow all
instructions listed below may result in electric shock, fire and/or serious injury.
Save all warnings and instructions for future reference.
1. Work area safety
●Keep work area clean and well lit. Cluttered or dark areas invite accidents.
●Do not operate power tools in explosive atmospheres, such as in the presence
of flammable liquids, gases or dust. Power tools create sparks which may ignite the
dust or fumes.
●Keep children and bystanders away while operating a power tool. Do not let
persons, especially children, not involved in the work touch the tool or the extension
cord and keep them away from the work area.
2. Electrical safety
●Power tool plugs must match the outlet. Never modify the plug in any way.
Do not use any adapter plugs with earthed (grounded) power tools. Unmodified
plugs and matching outlets will reduce risk of electric shock.
●Do not abuse the cord. Never use the cord for carrying, pulling or unplugging
the power tool. Keep cord away from heat, oil, sharp edges or moving parts.
Damaged or entangled cords increase the risk of electric shock.
●Use proper extension cord. Make sure your extension cord is in good condition.
When using an extension cord, be sure to use one heavy enough to carry the current
your product will draw. An undersized cord will cause a drop in line voltage resulting in
loss of power and overheating.
2

●Do not expose power tools to rain or wet conditions. Water entering a power tool
will increase the risk of electric shock.
●Avoid body contact with earthed or grounded surfaces, such as pipes, radiators,
ranges and refrigerators. There is an increased risk of electric shock if your body is
earthed or grounded.
3. Personal safety
●Stay alert, watch what you are doing and use common sense when operating
a power tool. Do not use a power tool while you are tired or under the influence
of drugs, alcohol or medication. A moment of inattention while operating power tools
may result in serious personal injury.
●Use personal protective equipment. Always wear eye protection. Protective
equipment such as a dust mask, protective glasses, non-skid safety shoes, hard hat or
hearing protection used for appropriate conditions will reduce personal injuries.
●Keep guards in place, in working order. Safety guards must never be removed when
the tool is being used.
●Prevent unintentional starting. Ensure the switch is in the off-position before
connecting to power source and/or battery pack, picking up or carrying the tool.
Carrying power tools with your finger on the switch or energising power tools that have
the switch on invites accidents.
●Remove any adjusting key or wrench before turning the power tool on. A wrench
or a key left attached to a rotating part of the power tool may result in personal injury.
●Do not overreach. Keep proper footing and balance at all times. This enables
better control of the power tool in unexpected situations.
●Dress properly. Do not wear loose clothing, gloves, neckties or jewelry which may
get caught in movine parts. Keep your hair, clothing, gloves or jewelry away
from moving parts.
●If devices are provided for the connection of dust extraction and collection
facilities, ensure these are connected and properly used. Use of dust collection can
reduce dust-related hazards.
●Do not let familiarity gained from frequent use of tools allow you to become
complacent and ignore tool safety principles. A careless action can cause severe
injury within a fraction of a second.
●Use only designated clamps to hold workpiece. It's safer than using your hand and
it frees both hands to operate tool.
3

●Never stand on tool. Serious injury could occur if the tool is tipped or if the cutting tool
is unintentionally contacted.
●Never leave tool running unattended. Turn power off. Don't leave tool until it comes
to a complete stop.
4. Power tool use and care
●Do not force the power tool. Use the correct power tool for your application. The
correct power tool will do the job better and safer at the rate for which it was designed.
●Do not use the power tool if the switch does not turn it on and off. Any power tool
that cannot be controlled with the switch is dangerous and must be repaired.
●Disconnect the plug from the power source and/or remove the battery pack, if
detachable, from the power tool before making any adjustments, changing
accessories, or storing power tools. Such preventive safety measures reduce the
risk of starting the power tool accidentally.
●Store idle power tools out of the reach of children and do not allow persons
unfamiliar with the power tool or these instructions to operate the power tool.
Power tools are dangerous in the hands of untrained users.
●Maintain power tools and accessories. Check for alignment of moving parts,
binding of moving parts, breakage of parts, mounting, guards, cord and any
other condition that may affect the power tool’s operation. If damaged, have
the power tool repaired before use. Many accidents are caused by poorly
maintained power tools.
●Keep cutting tools sharp and clean. Properly maintained cutting tools with sharp
cutting edges are less likely to bind and are easier to control.
●Use the power tool, accessories and tool bits etc. in accordance with these
instructions, taking into account the working conditions and the work to be
performed. Use of the power tool for operations different from those intended could
result in a hazardous situation.
●Keep handles and grasping surfaces dry, clean and free from oil and grease.
Slippery handles and grasping surfaces do not allow for safe handling and control of
the tool in unexpected situations.
●Do not use damaged grinding wheels.
●Use only grinding wheels and accessories that are recommended by the
manufacturer. Use of unauthorized accessories may result in personal injury.
●The grinding wheel will not be dressed.
4

●Please use the air spray gun and duster to clean all sharpened dusts from the
machine after finishing the grinding job.
●Direction of feed. Feed work into a blade or cutter against the direction of rotation of
the blade or cutter only.
5. Service
●Have your power tool serviced by a qualified repair person using only identical
replacement parts. This will ensure that the safety of the power tool is maintained.
Explanation of Labels
Indication of ground wiring
5

II. Intended Use
This grinding machine is suitable for grinding and sharpening 2 flutes, 3 flutes and 4 flutes
HSS / carbide end mill.
2 Flutes 3 Flutes 4 Flutes
III . Machine Installation Instruction
1. Environmental Condition
●Place the machine on a “flat” and “stable” working table.
● Operate the machine in dry environment and away from liquid.
● Make sure power plug and power cord are installed in proper location.
2. Power Supply
Make sure the local power supply is matching with the voltage specification from the
product label.
Please check the switch is in off position before plugging into socket outlet.
3. Motor Direction Test
①Plug the power cord into socket outlet.
②Check the grinding wheel protection cover is fastened by the screw.
③Quickly switch on and off the machine, then check if the rotating direction of
the right side grinding wheel is counterclockwise.
④Switch on the machine again and check if any abnormal sound.
(The Machine is equipped with carbon brush DC motor. A slightly grinding sound is
considered as normal condition.)
6

IV . Machine Devices Introduction
3 & 4 Flute End Gash Bushing Handle 2 Flute End Gash
Grinding Shelf (IIII)
3 & 4 Flute End Gash
Grinding Shelf (II)Warning Sign
Warning Sign Cutting Face
Grinding Shelf (III)
Adjustable Pin
Angle Indicator
Secondary Relief
Grinding Shelf (I)Switch
Positioning Shelf Grinding Wheel
Cutting Face
Adjustment Device
Bushing & Chuck Set
& Collet
Dust Collection Adapter
Hexagon Wrench (2, 3, 4 mm)
Extension Rod (3, 4, 6, 8, 10 mm)
For End Mill diameter:
Φ3.0 mm - Φ20.0 mm
Grinding Wheel
Fan
Plastic Protection Cover
Grinding Wheel Protection Cover
Fuse
Power Cord Power Socket
7

V. Dust Collection Adapter Assembly Steps
1. Thread the hex nut onto the suitable position of the threaded rod, align the end of the
threaded rod containing the hex nut to the tapped hole of grinding wheel cover, and turn
the threaded rod clockwise to thread the rod into the grinding wheel cover and tighten
lightly. (Fig. 5-1)
Grinding Wheel Cover
Hex Nut
Threaded Rod
Fig. 5-1
2. Align the hole in the center of the dust collection adapter to threaded rod. Push the dust
collection adapter to the end. (Fig. 5-2)
3. Assemble the washer and wing nut and tighten the wing nut to secure the dust collection
adapter. (Fig. 5-3)
Dust Collection Adapter
Fig. 5-2
Washer Wing Nut
Fig. 5-3
8

VI . Choose of Grinding Wheel & Accessories & Collet
1. Please unplug the power cord before changing grinding wheel.
2. Choose the proper grinding wheel according to the material of end mill.
●Carbide / Tungsten material end mill use SD grinding wheel (Standard).
●HSS material end mill use CBN grinding wheel (Optional).
3. For grinding Shelf (I) and Shelf (II), there are five different sizes of grinding wheel.
Choose the proper grinding wheel according to end mill’s cutting diameter
● Grinding Wheel A is for grinding the diameter from Φ3.0 mm - Φ5.0 mm.
● Grinding Wheel B is for grinding the diameter from Φ5.1 mm - Φ8.0 mm.
● Grinding Wheel C is for grinding the diameter from Φ8.1 mm - Φ12.0 mm.
● Grinding Wheel D is for grinding the diameter from Φ12.1 mm - Φ16.0 mm.
● Grinding Wheel E is for grinding the diameter from Φ16.1 mm - Φ20.0 mm.
4. Choose the proper bushing and chuck set according to the number of flute.
5. Choose the proper collet according to end mill’s diameter.
VII . Chuck Set Assembly Steps
1. Make sure there are no dust or scraps inside the clamping nut, collet and collet holder.
2. Put the collet into collet holder by 45° angle. (Fig. 7-1)
3. Screw in a little bit by clamping nut, then insert end mill shank into the clamping nut until the
end mill tip is about 5 mm out of the clamping nut (Fig. 7-2), slightly screw the chuck set to
tighten the end mill a little bit.
※Do not fully tighten the chuck set, make sure end mill can still be adjusted.
Collet
Collet Holder
Fig. 7-1
5 mm
Chuck set
Collet Holder
End Mill Collet
Clamping Nut
Fig. 7-2
(continued on next page)
9

(continued from previous page)
4. Turn the longer cutting edge of end mill to be parallel to the Slot No.1 of the clamping nut.
(Fig. 7-3)
2 Flute End Mill
Slot No.1
Parallel
Longer cutting edge
3 Flute End Mill
Slot No.1
Parallel
Longer cutting edge
4 Flute End Mill
Slot No.1
Parallel
Longer cutting edge
Fig. 7-3
※If the end mill is too short, the extension rod in the accessory is available for use.
Choose the proper extension rod according to the end mill’s shank diameter. Insert
end mill’s shank into the extension rod, and use 2 mm hexagon wrench to tighten
the side screw of the extension rod to secure the end mill. (Fig. 7-4)
※When assembling with the chuck set, put it in from the rear of the chuck set. (Fig. 7-5)
End Mill
Tightening Hexagon
Wrench
Extension Rod
Fig. 7-4
Chuck set
Fig. 7-5
10

VIII . The use of the Positioning Shelf
1. Preset the position of the alignment block. (Fig. 8-1)
①Loosen the set screw by counterclockwise.
②Pull out the alignment block to the end.
2. End mill positioning (Fig. 8-2) :
①Align Slot No.1 of the clamping nut to the pin on the
positioning shelf, insert the chuck set into the
positioning shelf and fit them with no gaps, then turn
the chuck set clockwise until it stops by the pin.
②Slowly move the alignment
block inward.
③Push the end mill to the end and
slowly turn it clockwise until the
outer corner of the end mill’s
longer cutting edge touches the
tip of the alignment block.
④Turn the set screw clockwise to
lock the alignment block.
⑤Tighten the chuck set to secure the end mill.
3. Gently turn the chuck set counterclockwise and take it out, make sure the end mill’s longer
cutting edge is parallel to the Slot No.1 of clamping nut (See Fig. 7-3).
※If the end mill's longer cutting edge is angled away from the Slot No.1 of clamping nut
(Fig. 8-3), change to the alignment block with a notch on the front, insert with the notch
facing up (Fig. 8-4), then reposition the end mill.
①
Set screw
②
Alignment block
Fig. 8-1
③
No gap between
chuck set and the
positioning shelf
①
④
⑤
②
Pin
Fig. 8-2
Slot No.1
Incorrect
Fig. 8-3
Alignment block
Fig. 8-4
※Make sure the positioning result is correct before starting the grinding procedure.
11

IX . The use of the Cutting Face Adjustment Device
This device is to adjust the width of the cutting face. (Fig. 9-1)
Cutting Face width
Adjustment Device
Fig. 9-1
1. Please turn it to “-” direction to the end then
set to “0”.
2. Turn to “+” direction to decrease the cutting face width.
Turn to “-” direction to increase the cutting face width.
12

X. 2 Flute End Mill Grinding Preparations
1. Secondary Relief Grinding Shelf (I) (Fig. 10-1)
①Move the adjustable pin on the Shelf (I) from the
bottom to top.
②Adjust the cutting face adjustment device to “0”,
after finishing the whole sharpening procedure,
then adjust this device according to your needs.
(See chapter “IX. The use of the Cutting Face
Adjustment Device”)
2. Cutting Face Grinding Shelf (III) (Fig. 10-2)
①Adjust the Shelf (III) to 3°.
②Insert 2 Flute Cutting Face Bushing into
the Shelf (III), align No.1 of the bushing to
the pin on the shelf, then insert it to the end.
※The ● green mark of the bushing should
align to the ● green mark on the shelf
when inserting the bushing.
Adjustable Pin
Shelf (I)
Adjustment
Device
Fig. 10-1
Pin
Shelf (III)
2 Flute
Cutting Face
Bushing
Green
mark
Angle
Indicator
Fig. 10-2
13

XI . 2 Flute End Mill Grinding Process
Grinding procedure: I, III, IIII
Turn the power switch on and wait about 10 seconds until the motor rotation is stable.
󳮓Do not hold the end mill shank while grinding, it may affect the grinding accuracy.
1. 2 Flute Secondary Relief Grinding (I) (Fig. 11-1)
Insert the chuck set into the Shelf (I), align Slot No.1
of clamping nut to the two pins on the shelf, push the
chuck set gently and turn it clockwise and counter-
clockwise until the grinding noise stops. Turn the
chuck set to grind the Slot No.2 in the same way.
2. 2 Flute Cutting Face Grinding (III) (Fig. 11-2)
Insert the chuck set into the bushing on the
Shelf (III), align Slot No.1 to the two pins where
marked as No.1, push the chuck set gently until
the grinding noise stops.
Take the chuck set out and turn the
bushing to No.2, align No.2 to the pin
on the shelf, then insert it to the end.
Insert the chuck set into the bushing,
align Slot No.2 to the two pins where
marked as No.2, push the chuck set
gently until the grinding noise stops.
3. 2 Flute End Gash Grinding (IIII) (Fig. 11-3)
Insert the chuck set into the Shelf (IIII),
align Slot No.1 to the two pins on the shelf,
push the chuck set gently until the grinding noise stops.
Turn the chuck set to grind the Slot No.2 in the same way.
Pin
Fig. 11-1
Pin 

Bushing
Fig. 11-2
Pin
Fig. 11-3
14

XII . 3 Flute End Mill Grinding Preparations
1. Secondary Relief Grinding Shelf (I) (Fig. 12-1)
①Move the adjustable pin on the Shelf (I) from the
bottom to top.
②Adjust the cutting face adjustment device to “0”,
after finishing the whole sharpening procedure,
then adjust this device according to your needs.
(See chapter “IX. The use of the Cutting Face
Adjustment Device”)
2. End Gash Grinding Shelf (II) (Fig. 12-2)
Insert 3 & 4 Flute End Gash Bushing into the Shelf (II),
align No.(I∙II) of the bushing to the pin on the shelf,
then insert it to the end.
※The ●pink mark of the bushing should align to the
●pink mark on the shelf when inserting the bushing.
3. Cutting Face Grinding Shelf (III) (Fig. 12-3)
①Adjust the Shelf (III) to 3°.
②Insert 3 Flute Cutting Face Bushing into
the Shelf (III), align No.1 of the bushing to
the pin on the shelf, then insert it to the end.
※The ● green mark of the bushing should
align to the ● green mark on the shelf
when inserting the bushing.
Adjustable Pin
Shelf (I)
Adjustment
Device
Fig. 12-1
3 & 4 Flute
End Gash Bushing
Shelf (II)
Pin
Pink mark
Fig. 12-2
Pin
Shelf (III)
3 Flute
Cutting Face
Bushing
Green
mark
Angle
Indicator
Fig. 12-3
15

XIII . 3 Flute End Mill Grinding Process
Grinding procedure: I, II, III
Turn the power switch on and wait about 10 seconds until the motor rotation is stable.
󳮓Do not hold the end mill shank while grinding, it may affect the grinding accuracy.
1. 3 Flute Secondary Relief Grinding (I) (Fig. 13-1)
Insert the chuck set into the Shelf (I), align Slot No.1 of
clamping nut to the two pins on the shelf, push the chuck
set gently and turn it clockwise and counterclockwise until
the grinding noise stops. Turn the chuck set to grind the
Slot No.2 and Slot No.3 in the same way.
2. 3 Flute End Gash Grinding (II) (Fig. 13-2)
Insert the chuck set into the bushing on the Shelf (II),
align Slot No.1 to the two pins where marked as
No.(I∙II), push the chuck set gently until the grinding
noise stops. Turn the chuck set to grind
the Slot No.2 in the same way.
Take the chuck set out, turn the bushing to
No.(III), align No.(III) to the pin on the shelf,
then insert it to the end.
Insert the chuck set into the bushing, align
Slot No.3 to the two pins where marked as
No.(III), push the chuck set gently until the
grinding noise stops.
3. 3 Flute Cutting Face Grinding (III) (Fig. 13-3)
Insert the chuck set into the bushing on
the Shelf (III), align Slot No.1 to the two
pins where marked as No.1, push the
chuck set gently until the grinding noise
stops.
Take the chuck set out, turn the bushing
to No.(2 ∙3), align No.(2 ∙3) to the pin on
the shelf, then insert it to the end.
Insert the chuck set into the bushing,
align Slot No.2 to the two pins where marked as No.(2 ∙3), push the chuck set gently until
the grinding noise stops. Turn the chuck set to grind the Slot No.3 in the same way.
Pin
Fig. 13-1
 

Bushing Pin
Fig. 13-2
Pin 

Bushing
Fig. 13-3
16

XIV . 4 Flute End Mill Grinding Preparations
1. Secondary Relief Grinding Shelf (I) (Fig. 14-1)
①Move the adjustable pin on the Shelf (I) from the
top to bottom.
②Adjust the cutting face adjustment device to “0”,
after finishing the whole sharpening procedure,
then adjust this device according to your needs.
(See chapter “IX. The use of the Cutting Face
Adjustment Device”)
2. End Gash Grinding Shelf (II) (Fig. 14-2)
Insert 3 & 4 Flute End Gash Bushing into the Shelf (II),
align No.(1 ∙3) of the bushing to the pin on the shelf,
then insert it to the end.
※The ●pink mark of the bushing should align to the
●pink mark on the shelf when inserting the bushing.
3. Cutting Face Grinding Shelf (III) (Fig. 14-3)
● For grinding the diameter from Φ3.0 - 8.0 mm.
①Adjust the Shelf (III) to 12°.
②Choose 4 Flute Cutting Face Bushing (12 deg).
● For grinding the diameter from Φ8.1 - 12.0 mm.
①Adjust the Shelf (III) to 7°.
②Choose 4 Flute Cutting Face Bushing (7 deg).
● For grinding the diameter from Φ12.1 - 20.0 mm.
①Adjust the Shelf (III) to 3°.
②Choose 4 Flute Cutting Face Bushing (3 deg).
Insert the proper bushing into the Shelf (III), align No.1 of
the bushing to the pin on the shelf, then insert it to the end.
※
The ● green mark of the bushing should align to the
● green mark on the shelf when inserting the bushing.
Adjustable Pin
Shelf (I)
Adjustment
Device
Fig. 14-1
3 & 4 Flute
End Gash Bushing
Shelf (II)
Pin
Pink mark
Fig. 14-2
Pin
Shelf (III)
4 Flute
Cutting Face
Bushing
Green
mark
Angle
Indicator
Fig. 14-3
17

XV . 4 Flute End Mill Grinding Process
Grinding procedure: I, II, III
Turn the power switch on and wait about 10 seconds until the motor rotation is stable.
󳮓Do not hold the end mill shank while grinding, it may affect the grinding accuracy.
1. 4 Flute Secondary Relief Grinding (I) (Fig. 15-1)
Insert the chuck set into the Shelf (I), align Slot No.1 of
clamping nut to the two pins on the shelf, push the chuck set
gently until the grinding noise stops. Turn the chuck set to
grind the Slot No.2, Slot No.3 and Slot No.4 in the same way.
2. 4 Flute End Gash Grinding (II) (Fig. 15-2)
Insert the chuck set into the bushing on the Shelf (II),
align Slot No.1 to the two pins where marked as
No.(1 ∙3), push the chuck set gently until the grinding
noise stops. Turn the chuck set to grind the Slot No.3
in the same way, then take the chuck set out.
Turn the bushing to No.(2 ∙4), align No.(2 ∙4) to
the pin on the shelf, then insert it to the end.
Insert the chuck set into the bushing, align
Slot No.2 to the two pins where marked as
No.(2 ∙4), push the chuck set gently until the
grinding noise stops. Turn the chuck set to
grind the Slot No.4 in the same way.
3. 4 Flute Cutting Face Grinding (III) (Fig. 15-3)
Insert the chuck set into the bushing on
the Shelf (III), align Slot No.1 to the two
pins where marked as No.1, push the
chuck set gently until the grinding noise
stops, then take the chuck set out.
Turn the bushing to No.(2 ∙3 ∙4), align
No.(2 ∙3 ∙4) to the pin on the shelf, then
insert it to the end.
Insert the chuck set into the bushing,
align Slot No.2 to the flat key where
marked as No.(2 ∙3 ∙4), push the chuck set gently until the grinding noise stops. Turn the
chuck set to grind the Slot No.3 and Slot No.4 in the same way.
Pin
Fig. 15-1
 

Bushing Pin
Fig. 15-2
Pin Bushing 

Flat key
Fig. 15-3
18