Grinding

Machines

G&NGenauigkeitsMaschinenbauNürnbergGmbH

Precision Surface Grinding MachineMPS VTG II

Aus

gabe

12.

02

G&N Genauigkeits Maschinenbau Nürnberg GmbH, Wetterkreuz 35, 91058 Erlangen,Telefon: (09131) 7576-0, Telefax: (09131) 771291

E-mail: info@grinders.de, Internet: http://www.grinders.de

Operating Manual

General

This directive is intended for personnel response to operate the grindingmachine.

The complete technical documentation shall all the times be kept near thegrinding machine.

Thie operating directive points out essential details for the application of thegrinding machine.

With hints contained in this directive, failures at the grinding machine may beavoided thus permitting troublefree operation. It is therefore of utmostimportance that personnel delegated to operate the machine is familiar withthis directive, especially the chapter for safety.

It is recommended to carefully study the directive prior to taking machine tooperation, as G&N will not come up for damages or operating failures resultingfrom nonobservance of this directive.

Note:

Technical modifications serving for improvement of the grinding machine aresubject to exception as compared to description and notes of this directive.

Purpose of Machine:

The precision grinding machine MPS VTG II is exclusively designedfor resharpening punching tools made of steel.Any other application is considered contrary to intended purpose.The manufacturer will not accept claims for damages resulting fromsuch use; the user will be responsible for such application.

Precision Surface Grinding MachineMPS VTG II

SPECIFICATION

Order No.: _______________

Mfg. Year: _______________

El. Connection V/Hz : _______________

2002

400V / 50Hz

Connected Load 4 kVAGrinding Motor: 3,3 kW

440V50Hz2850 min -1

Compressed air supply 6 bar

Grinding Wheels

CBN ø 200X34X32 mmDiamant ø 200X34X32 mm

Precision 0,005 mm

Rotary Table ø 320 mm

Max. grinding height: ca. 300 mm

Space (depending on order) ca. 760 x 650 mm

Noise level < 67dB(A)

Weight ca. 300 kgs

TECHNICAL DATAMPS VTG II

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Contents directory

1 Safety ............................................................................. 11.1 Safety indicators ......................................................................... 1

1.1.1 Warning symbols ................................................................................. 11.1.2 Attention-indicator ............................................................................... 1

1.2 Compliance stipulated operation ............................................. 21.3 Approved personnel .................................................................. 21.4 Fundamental safety indicators ................................................. 21.5 Especial type of danger; electricity ......................................... 41.6 Especial type of danger; laser .................................................. 41.7 Self-made modifications ban .................................................... 41.8 Environmentally friendly disposal ........................................... 4

2 Unpacking, installation and commissioning................... 52.1 Unpacking the MPS VTG II ........................................................ 52.2 Transport to installation site ..................................................... 62.3 Installation.................................................................................... 7

2.3.1 Installation site ..................................................................................... 72.3.2 Installation ............................................................................................ 7

2.4 Connecting and commissioning .............................................. 72.4.1 Electrical connection ........................................................................... 72.4.2 Coolant system .................................................................................... 92.4.3 Compressed air ................................................................................... 92.4.4 Grinding wheel ................................................................................... 102.4.5 Rotary table and workpiece clamping devices. .............................. 102.4.6 Commissioning .................................................................................. 10

3 Manual operation of the MPS VTG II ........................... 113.1 Operating elements front plate ............................................... 113.2 Stepcon operating panel ......................................................... 12

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3.3 Switching the machine functions manually .......................... 143.3.1 Machine main switch, EMERGENCY switch .................................... 143.3.2 Preselection Manual/ Automatic ....................................................... 143.3.3 Spindle On/Off .................................................................................... 143.3.4 Rotary table On/Jog ........................................................................... 143.3.5 Automatic start ................................................................................... 153.3.6 Emergency return .............................................................................. 153.3.7 Grinding spindle infeed ..................................................................... 153.3.8 Rotary table speed............................................................................. 15

4 Automatic mode ........................................................... 164.1 Programming the grinding cycle............................................ 164.2 Clamping the workpiece .......................................................... 184.3 Preselection rotary table speed.............................................. 18

4.4 Grinding cycle ....................................................................................... 194.4.1 Work sequence .................................................................................. 194.4.2 Error codes ........................................................................................ 20

4.5 Adjustment GAP ........................................................................ 204.5.1. Adjustment of the GAP distance ...................................................... 20

5. - Dropped - .................................................................. 21

6 Rotary table .................................................................. 226.1 Description ................................................................................ 226.2 Rotary table angel setting (sine table) .................................... 226.3 Tool fixturing ............................................................................. 22

7 Grinding wheels ........................................................... 237.1 Types .......................................................................................... 237.2 Mounting schematic ................................................................. 237.3 Replacing the CBN grinding wheel ........................................ 247.4 Sharpening the CBN grinding wheel ..................................... 25

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8 Maintenance ................................................................. 278.1 Motor and spindle..................................................................... 278.2 Rotary table ................................................................................ 278.3 Fine-infeed ................................................................................. 278.4 Grinding wheelhead guideways ............................................. 27

9 Appendix ...................................................................... 299.1 Machine elements ..................................................................... 299.2 MACHINE DATA menu .............................................................. 319.3 TEST INPUT menu .................................................................... 33

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ATTENTION

1 Safety

1.1 Safety indicators

1.1.1 Warning symbols

These symbols are found within this operating manual asoccupational safety indicators wherever a danger to personnel life orlimb exists. They are individually classified as follows:

DANGER!

Non observance of this indicator LEADS to massive bodily harm ordeath. Heed exactly the stipulated rules of conduct accompanyingthis indicator/symbol!

WARNING!

Non observance of this indicator CAN LEAD to massive bodily harmor death. Heed exactly the stipulated rules of conduct accompanyingthis indicator/symbol!

CAUTION!

Non observance of this indicator can lead to minor injuries ormaterial damage. Heed the stipulated rules of conductaccompanying this indicator/symbol!

Heed these indicators and in these cases always conduct yourselfwith care. Also inform other operators of these occupational safetyindicators. Further to the indicators found in this operating manual itis also important to heed the general safety rules and rules for theprevention of accidents.

1.1.2 Attention indicator

The indicator ”Attention” is found in all places in the operatingmanual where something must be especially heeded to ensureadherence of guidelines, specifications, indicators, and that theoperations are correctly processed, as well as preventing damageand/or destruction to the machine and/or to other system parts.

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1.2 Compliance stipulated operation

The MPS VTG II grinding machine is designed for resharpeninghardened steel punching dies.

Using the machine for other applications is considered asnoncompliance stipulated. The manufacturer is not liable for anydamage resulting from such a case and the risks therein will beborne solely by the operator.

1.3 Approved personnel

The MPS VTG II grinding machine is built to state-of-the-art and isoperationally safe. Nevertheless this machine can be a danger to lifeand limb of operators or third parties when used incorrectly or byuntrained personnel or for noncompliance stipulated applications.

Every person in the operator’s company engaged with any of thefollowing; setup, installation. Operation, maintenance and service ofthe MPS VTG II grinding machine is obliged to have read andunderstood the operating manual and especially the chapter”Safety”. It is recommended that the operator has his personnelconfirm having done so in writing.

1.4 Fundamental safety indicatorsn The grinding machine may only be operated, serviced andmaintained by authorized, trained and schooled personnel. Thesepersonnel must have received a special schooling regardingpossible dangers.

n Responsibilities regarding setup, maintenance and repair ofthe grinding machine must be clearly defined and heeded in orderto hinder, with regards to safety, any incompetent handling.

n Working with the electrical equipment may only be carried outby qualified specialists.

n The EMERGENCY STOP SWITCH must be switched off in anysituation requiring that the machine functions be immediatelyswitched off.

n Don't remove or modify any parts of the safety equipment!

n Grinding wheels may only be mounted by reliable andexperienced personnel who, while doing so, heed the regulationsfound in this operating manual!

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n Sharpening or dressing of the grinding wheel may only takeplace using the respective fixtures (never by hand).

n Only use grinding wheels that have been tested and areapproved for the grinding spindle rpm!

n The grinding wheel must be tested for freedom of motion afterany setup or maintenance work!

n Test the grinding wheel for freedom of motion prior to switchingon the grinding spindle!

n Any mode of operation which could impair the safety of thegrinding machine is prohibited!

n The operator is responsible for ensuring that no unauthorizedpersonnel works on the grinding machine.

n The operator is obliged to inspect the grinding machine, atleast one time per shift, for externally noticeable damage ordefects. Any changes that have occurred (including operationalbehavior) must be notified immediately to the relevantdepartment!

n The operating company is obliged to ensure that the grindingmachine is only used when it is in perfect running condition!

n The operating company is obliged to ensure, by means ofsuitable directives and inspections, that the working area, at andaround the grinding machine, is kept clean and uncluttered!

n A categorical rule is that no safety device may be dismountedor set such that it no longer functions. If it is necessary todeactivate/disassemble a safety device in order to setup, repairor maintain the machine, then the safety device must beimmediately reactivated/assembled upon completion of saidsetup, repair or maintenance!

n Prior to beginning such work on the grinding machine, ensureno drives or auxiliary devices can inadvertently be switched on!Lock the main switch using a padlock.

n The local safety and accident prevention regulations are alsovalid and must in every case be heeded when operating thegrinding machine.

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1.5 Especial type of danger - electricityn Work on electrical systems may only be carried out by qualifiedelectricians!

n Prior to opening the electrical cabinet switch the main switch offand secure with a padlock!

n Prior to assembly work de-electrify the electrical cabinet bydisconnection of the power supply!

n The built-in safety devices (e.g. ground resistance) must bechecked after respective electrical assembly work or maintenance.

n The machine’s electrical equipment must be regularly inspectedand/or tested. Defects such as loose connections, braised cables,etc. must be immediately fixed!

n VDE-regulations as well as the local energy supply companyregulations must be observed and heeded!

n Only use originally supplied fuses with the specified amperagevalues!

1.6 Especial type of danger - laser

The MPS VTG II equipped with a touch free laser measurement of theworkpiece.

n Do not look directly into the laser beam

n Take care that the laser beam can't reach your eyes byreflection

1.7 Self-made modifications bann Self-made modifications and changes that could affect thesafety of the grinding machine are not allowed.

n Do not make any modifications and changes that could affectthe safety of the grinding machine, without prior permission of themanufacturer! This is also applicable to assembly and settings on/to safety devices and valves.

1.8 Environmentally friendly disposal

Ensure that operating and auxiliary materials are disposed of safelyand in an environmentally friendly manner!

Be sure to heed local government regulations!

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2 Unpacking, installation and commissioning

2.1 Unpacking the MPS VTG II

The MPS VTG II comes delivered bolted to a palette.

Remove the protective foil and loosen the clamping bolts.

Dispose of the packaging material as per local governmentregulations.

Inspect the MPS VTG II for any damage that may have occurredduring transport and report to us immediately if any damage is found.

Check that the enclosed standard and special accessories conformwith the delivery note and packing list.

All bare metal machine parts have been greased to protect againstrust. This protective grease must be removed using a cleaning clothand, if necessary, with the addition of some petroleum.

CAUTION!

Benzine or trichlorethylene (Tri) are not suited for cleaning!These materials are unhealthy and remove all traces of grease(danger of rust).

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2.2 Transport to installation site

The best way to transport the machine to theinstallation site is with a suitably sized forklift(machine weight approx. 300 kgs).

Use the forklift as shown in Illustration 1.

CAUTION!

Take care when lifting the machine thatno cables or hoses get squashed.

Illustration1: forklift position

Illustration2: siting diagram

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2.3 Installation

2.3.1 Installation site

Place the MPS VTG II in an area which has sufficient light and space(see Installation diagram Illustration 2). The installation site may notbe near any vibration inducing machines and must be on a levelground with sufficient load carrying capacity.

The MPS VTG II must be connected to an electrical supply accordingto the data plate of the machine (clockwise rotational field).

2.3.2 Installation

Place the machine exactly horizontal by adjusting the vibrationdampers (Illustration 3) and check using a spirit level.

2.4 Connecting and commissioning

2.4.1 Electrical connection

WARNING!

Dangerous electrical voltage! Possibility of severe or deadlyinjury.

Switch off the power supply and secure it againstunauthorized switching on when doing any work on theelectrical system.

Illustration 3: vibration dampers

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When connecting the machine observe the VDE-regulationsas well as the local energy supply company regulations.

Check the supplied safety measures (e.g. measure the groundresistance) after connection.

The MPS VTG II has been set at the manufacturing factory toconnection values found on the data plate. Connecting the machineto a power supply system with deviating values is not alwayspossible. If such a case arises please contact G&N in order to clarifynecessary measures.

The MPS VTG II is delivered with ready to use mounted connectionline and plug. You must check the rotation direction of the grindingmotor during set up.

Switch the electricity back on and check the rotational direction ofthe spindle motor ( arrow on the grinding wheel guard). If therotational direction does not correspond with the arrow, then therotational direction is easily corrected by exchanging two or threepositions of the power supply connectors (L1, L2, L3).

CAUTION!

The motor terminal connections may not be changed.This could cause damage to the MPS VTG II.

Illustration 4: electrical connections

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2.4.2 Coolant system

The coolant container with filter unit is found in the machine base.The coolant is conveyed through the center of the grinding wheel(through hollow spindle). The amount of coolant is regulated usingthe ball valve found to the left of the machine housing. The usedcoolant runs back to the container through a pipe; the grinding slurryis removed by a paper filter unit on top of the container.

The coolant system has been finish assembled and connected at themanufacturer’s factory. We recommend though that the hose linesare checked for damage and tightness prior to commissioning.

Fill the coolant container with water and coolant additive (e.g. ARALMultrol).

Place a sheet of filter paper (paper roll) over the sieve plate of thecontainer.

2.4.3 Compressed air

The connection for the compressed air supply (Standard plug) is atthe machine back left side. The compressed air is needed for

n keeping the bores of the laser system free of water and dirt(sealing air). The sealing air is activated when the machine mainswitch is put on.

n remove water drops from the workpiece before and after grinding(blow off nozzles)

Container

Sieve plate

Pipe

Paper roll

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CAUTION!

The sealing air keeps the bores of the laser system free ofwater and grinding residues.

Do not switch off the sealing air immediately after grinding.

2.4.4 Grinding wheel

The grinding wheel is already mounted and ready to run.

2.4.5 Rotary table and workpiece clamping devices.

The workpiece clamping device assembly as well as the setting therotary table are described in chapter 6.

Select the most suited workpiece clamping fixture and assemble itas stated in the operating manual.

Set the rotary table as stated in the operating manual.

The MPS VTG II is now correctly connected.

2.4.6 Commissioning

All operating elements are found on the front side of the electricalcabinet (see Chap. 3).

Switch the main switch (EMERGENCY switch) to ON

The MPS VTG II is now ready to run.

Sealing airconnection

Laser housing

Blow off airconnection

Abb.: 5 compressed air use

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3 Manual operation of the MPS VTG II

3.1 Operating elements front plate

ON/OFF

Display andkeyboard

Emergencyreturn

Automaticstart

PreselectManual/Auto

Rotary tableOn/Jog

SpindleOn/Off

Emergency Stop

Abb.: 6 front plate

Rotary tablespeed

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3.2 Stepcon operating panel

By pressing the 17 keys the grinding wheelhead feeds-in,

alternatively retracts in increments of 5 µm.

By pressing the 8 2 keys the grinding wheelhead feeds-in slowly,alternatively retracts slowly.

The speed can be set in the menu MACHINE DATA (See Chap. 9).

By pressing the 9 3 keys the grinding wheelhead feeds-in quickly,alternatively retracts quickly.

The speed can be set in the menu MACHINE DATA (See Chap. 9).

The keys are only effective after pre-selecting “manual”.

During data entry the last shown figure in the display is erased whenthis key is pressed. Thus the displayed value can be completelyerased.

The currently selected menu can be exited by pressing the ESC key.

The previous menu is automatically displayed. If data has beenaltered, then the data will first be checked.

esc.

Del.

17

8 2

9 3

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The menu program will be displayed by pressing the PROGRAMSELECT key.

NEXT

Press the key to scroll through the program sets 1 - 5

ENTER

The displayed value, alternatively a display of possible selections,will be confirmed by pressing the ENTER key.

During data entry the shown value in the display is erased when thiskey is pressed. Thus the displayed value can be completely erased.

SET UP

Use SET UP to set a specific value on the fine downfeed scale.

Example: Set the workpiece surface to the value "0"

n preset mode manual;n clamp workpiece;n move the grinding head carefully down until the grinding wheel

touches the workpiece slightly;n press key F1;

n erase displayed value with ? ;

n enter "0"

Now the workpiece surface is set to value "0"

INPUT/OUTPUT TEST

The input/output test is invoked by pressing the F2 key.

MACHINE DATA

The menu is invoked by pressing the F3 key. (Enter password:9876).

Adjust GAP distance

F1

F4

F3

F2

?

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3.3 Switching the machine functions manually

3.3.1 Machine main switch, EMERGENCY switch

Turn the switch clockwise to turn the machine on.

n The machine is ready-to-operate.

EMERGENCY STOP

Press the switch in all situations requiring that the machine functionsbe immediately stopped.

Turn anticlockwise to release.

3.3.2 Preselection Manual/ Automatic

Switch in “Manual” setting

n The MPS VTG II functions (spindle, rotary table, infeed) can bemanually operated.

Switch in “Auto” setting

n The MPS VTG II is in automatic mode

3.3.3 Spindle On/Off

If “Manual” has been preselected

Press the button to turn on the spindle motor.

This turns on the coolant motor simultaneously.

Pressing the button again turns off the spindle motor.

3.3.4 Rotary table On/Jog

Switch in middle setting

n Rotary table is switched off

Switch in “On” setting

n Rotary table rotates at preselected rpm

n An proximity switch ensures that the rotary table remainsstanding in its base position when switched off.

Switch pressed to “Jog” setting (switch does not lock in)

n Rotary table rotates as long as the switch is held

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3.3.5 Automatic start

Manual mode preselected:

After pressing the key the grinding head is downfeed to the switchover point (+GAP) and stopped then. (Function is used to calibratethe touch grind control).

Automatic Mode preselected:

Pressing the key starts the automatic grinding cycle.

3.3.6 Emergency return

Press this button in order to interrupt the current grinding cycle.

n The grinding spindle moves to its initial position, then

n rotary table, spindle motor and coolant are switched off.

3.3.7 Grinding spindle infeed

Press the 71 keys

The grinding wheelhead feeds-in, alternatively retracts in incrementsof 5 µm.

Press the 82 keys

The grinding wheelhead feeds-in slowly, alternatively retracts slowly.

The speed can be set in the menu MACHINE DATA.

Press the 93 keys

The grinding wheelhead feeds-in quickly, alternatively retractsquickly.

The speed can be set in the menu MACHINE DATA .

The keys are only effective after pre-selecting “Manual”.

3.3.8 Rotary table speed

Preselection of the rotary table speed during grinding process(infinitely variable from 0 to 30 rpm).

17

8 2

9 3

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4 Automatic modeGrinding in automatic mode comprises of the following steps:

1. Programming of the grinding cycle

2. Clamping the workpiece

3. Preselection of the rotary table speed

4. Grinding cycle

5. Workpiece removal

4.1 Programming the grinding cycleThe following values can be varied/selected in the grinding cycle:

n Roughing amount

n Roughing speed

n Finishing amount

n Finishing speed

n Spark out time

The values are entered using the Stepcon panel.

You can enter up to five different program cycles.

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Entering the values

Press the key

Press the key ESC to close the menu; the entered data will beadopted.

Please keep in mind that due to the machine security settings theroughing process starts 100µm above the workpiece (100µm freshair grinding).

ATTENTION

C

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4.2 Clamping the workpiece

Workpiece clamping is described in Chapter 6.

First select the required workpiece fixture and mount it on the rotarytable.

Set the required rotary table angle.

Carefully clamp the workpiece.

CAUTION!

Ensure that the workpiece is correctly clamped.Danger of injury due to parts being ”thrown out”.

4.3 Preselection rotary table speed

Preselect the rotary table speed at the potentiometer (max. speed is30rpm).

CAUTION!

If "zero" is selected, the rotary table will not turn duringgrinding. The workpiece might be damaged.

A B

CD

Illustration. 5: Workpiece fixtures AMADA ®- System (selection)A: Matrices; B: Punch A; C: Punch B; D: Punch E

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4.4 Grinding cycle

Set select switch to AUTO, you will be asked to select a grindingprogram (scroll with key NEXT, confirm with ENTER).

The selection of a grinding program is only possible afterswitching from MANUAL to AUTO . If you want to change togrinding program between to cycles, first switch from AUTO toMANUAL and back.Editing of the grinding Programs is only possible at MANUAL.

4.4.1 Work sequence

Press AUTO START

1. Rapid downfeed to the switch over point, e.g. until the laserbeam is interrupted by the upper edge of the workpiece.

Message: Engaging punch

2. Very slow upfeed, until the laser beam can pass again. Now thecorrect starting point is reached.

3. Downfeed with selected GAP speed until the programmed GAPdistance ( = security distance workpiece - grinding wheel) isreached. 100µm before the workpiece is reached, the grindingmotor, the cooling supply and the rotary table are switched on antthe downfeed speed tis switched to preselected roughing speed.

Message: Stock removal

4. Roughing, after the roughing amount is done the downfeedswitches to finishing speed

Message: Stock removal

5. Finishing, after the finishing amount is done the downfeed isswitched off an sparkout starts

Message: Stock removal

5. Sparkout.Message: s

6. The grinding wheel head lifts by the entered amount.Message: Lift off

7. Retracts to the start position.Message: Retract .

If the grinding cycle does not start , not all preconditions are fulfilled.

ATTENTION

shining

shining

blinking

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4.4.2 Error codes

DOOR OPEN

The proximity switch of the sliding door was not actuated beforepressing key AUTO START.

Close door and press AUTO START again

GAP LOW

Grinding head position too low (below switch over point).

Switch to MANUAL and move grinding head up until the proximityswitch gets clear.

PUNCH ACTIVE

Grinding head position too low (below switch over point).

Switch to MANUAL and move grinding head up until the proximityswitch gets clear.

4.5 Adjustment GAP

The value of the GAP distance (=safety distance) is set at thefactory.

The wearing of the CBN grinding wheel enlarges the distance bet-ween wheel and workpiece at the starting point. If the GAP-distanceremains unchanged, the switch over from GAP to roughing willhappen too early and so the stock removal is too low.

Enlarge the GAP distance carefully and in slow steps.

CAUTION!

If the GAP distance is adjusted too large, the grinding wheelwill hit the workpiece at GAP speed. Thus might damage thegrinding wheel, the grinding spindle or/and the workpiece.

4.5.1. Adjustment of the GAP distance

The overall distance between grinding wheel and workpiece at thestarting point is set to 3500µm. This distance can be divided into theGAP distance (3400µm) and 100µm safety distance.

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The amount of 100µm fresh air grinding must be always kept.

Procedure

1. Clamp workpiece.

2. Preselect MANUAL and press key 2 to move the grindinghead down.

3.Stop downfeed as soon as the grinding wheel reaches thestarting point (switch over to GAP).

4. Press F1 SET UP and set the position to "0".

5. Move down the grinding wheel carefully (press key 2 ;grinding motor and rotary table switched off ), until thegrinding wheel just touches the workpiece.

6. Read the position of the grinding wheel (stepcon display). Thevalue (ex. 3750µm) is the overall distance

7. The new GAP distance is (example) 3750µm - 100µm =3650µm.

8. Press key F4 and enter the new GAP distance.

5. - Dropped -

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6 Rotary table

6.1 Description

The rotary table is designed for mounting of workpiece clampingfixtures up to a diameter of 320 mm.

The rotary table rotational speed infinitely variable from 0 - 30 rpm.

6.2 Rotary table angel setting (sine table)

In order to grind workpieces with a taper, the rotary table can betilted up to 12° from the horizontal position.

For this purpose the rotary table is hinged with bearings on one side.The angle is set by turning an infinitely variable eccentric disc (withangular scale) mounted on the rotary table.

1 Loosen the clamping screw with an allen key

2 Turn the eccentric disc until the required angle correspondswith the mark on the base plate (it is sometimes necessary toslightly raise the rotary table on the side).

3 Retighten the clamping screw

6.3 Tool fixturing

look at the special operating instruction

Eccentric disc

Clamping screw

Illustration 10: Eccentric disc rotary table

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7 Grinding wheels

7.1 Types

The MPS VTG II is basically designed for using CBN grindingwheels.

The supplied CBN grinding wheel has proven to be very good forgrinding hardened tool steels.

As an alternative diamond grinding wheels can also be usedwhereby the mounting and sharpening processes are the same asthose for CBN grinding wheels.

7.2 Mounting schematic

Nut SW 243 allen screws

M5 x 20 DIN 912

(allen key No. 4)

Stop plate

Flange

Spindle

Grinding wheel

Abb.: 9 Mounting schematic grinding wheel

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7.3 Replacing the CBN grinding wheelThe grinding wheel must be replaced if damaged or it is too worndown (< 0.5mm) to be used.

CAUTION!

Prior to replacing the grinding wheel ensure that the mainswitch is switched off and that it can not be inadvertentlyturned on. Padlock the main switch.

Obey the following:

1. Move Grinding Head up.

2. Unscrew the three allen screws and remove the grinding wheel.

3. Mount new grinding wheel and fasten the allen screws again.

Remove the grinding wheel with flange:

1. Move grinding head upwards.

2. Remove stop plate; Loosen nut (SW 24) (left-hand thread!). Ascounter pressure stick in the supplied open-jawed wrench SW 27above the grinding motor

3. Pull the grinding wheel and flange off the spindle using thesupplied drawing-off tool.

4. Disassemble the grinding wheel by loosening the allen screwswith an allen key and remove the grinding wheel.

Abb.: 10 mounting grinding wheel

allenscrews

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5. Mount a new grinding wheel and screw the flange backtogether.

6. Pushing lightly by hand mount the grinding wheel flange backonto the grinding spindle. It is of utmost importance to avoidmounting the flange to the spindle taper with too much force!

7. Retighten the nut and the stop plate.

Heed the following indicators precisely:

n Grinding wheel assemblies may only be mounted by reliableand experienced personnel.

n It is extremely important that the internal taper of the grindingwheel flange and the spindle taper are absolutely clean beforemounting the grinding wheel assembly.

n When mounting the grinding wheel assembly great care mustbe taken to ensure perfect runout.

n Even the smallest of foreign bodies between the two mountingsurfaces can cause runout and, if once pressed in, can only becorrected with great difficulty. Damage of this type can only becorrected by very careful scraping.

7.4 Sharpening the CBN grinding wheel

After mounting a new CBN grinding wheel it must be sharpened,alternatively be re-sharpened after being used for a long time.

Resharpening is necessary when the CBN bonding has closed-up orbecome smooth due to high loading or grinding of difficult workpiecematerials.

The residue clinging to the bonding can be removed using thesupplied sharpening tool.

ATTENTION

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Bolt the sharpening tool to the rotary table as you would a die.

Follow these instructions:

1. Mark the grinding wheel bond with a felt tip pen;(only when sharpening a new grinding wheel)

2. Clamp the sharpening tool

3. Select automatic; enter sharpening data

4. Start automatic cycle.

5. At the end of the automatic cycle, using a mirror, check if thefelt tip marking has been ground off. If necessary repeat thedressing process.(only when sharpening a new grinding wheel)

6. Remove sharpening tool.

Abb.: 11 sharpening tool

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8 MaintenanceIncluded in the scope of supply of the MPS VTG II is a grease gun tolubricate the fine-infeed and the grinding wheelhead guideways. Usecommercially available bearing grease for lubricating.

8.1 Motor and spindle

Motor and spindle are maintenance free.

8.2 Rotary table

The rotary table has no lubrication points.

8.3 Fine-infeed

Lubricate the fine-infeed screw spindle every 100 working hours or 2 weeks with grease using the supplied grease gun.

1 Switch the machine main switch to "OFF".

2 Unscrew the machine's rear panel.

3 Using the grease gun apply a little grease to the markedlubrication points (see sticker).

4 Screw the machine's rear panel back on.

8.4 Grinding wheelhead guideways

There are lubrication points on the grinding wheelhead guideways.

Lubricate every 100 working hours or 2 weeks with grease using thesupplied grease gun.

1 Drive the grinding wheelhead upwards, until the proximityswitch is triggered.

2 Remove the stoppers out of the lubrication holes to the left andthe right of the grinding area (see sticker).

3 Apply a little grease using the grease gun to each of thelubrication holes on the grinding wheelhead guideways.

4 Press the stoppers back into the lubrication holes.

5 Drive the grinding wheelhead back downwards.

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Rotary table

Main switch

9 Appendix

9.1 Machine elements

Coolant tankwith pump

Fine-infeed

Motor

Grinding wheelguard

DisplaySignal lamp

EmergencyStop

Abb.: 12 machine components

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9.2 MACHINE DATA menu

The machine initial settings are stipulated in the MACHINE DATAmenu.

The menu is password protected.

The parameters programmed by G&N prior to delivering themachine have been optimized and should not be changedwithout a compelling reason.

Press F3

ATTENTION

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9.3 TEST INPUT menu

The machine switch functions can be tested in this menu.

Press F2

MPS VTG II

OPERATING MANUAL