haas VMC 96-8100 Service Manual
Haas Technical Publications
Manual_Archive_Cover_Page Rev A
any other party automatically voids the factory warranty.
June 6, 2013
HAAS SERVICE AND OPERATOR MANUAL ARCHIVE
VMC Service Manual 96-8100 English December 15 1994
• This content is for illustrative purposes.
• Historic machine Service Manuals are posted here to provide information for Haas machine owners.
• Publications are intended for use only with machines built at the time of original publication.
• As machine designs change the content of these publications can become obsolete.
• You should not do mechanical or electrical machine repairs or service procedures unless you are qualied
and knowledgeable about the processes.
• Only authorized personnel with the proper training and certication should do many repair procedures.
WARNING: Some mechanical and electrical service procedures can be
extremely dangerous or life-threatening.
Know your skill level and abilities.
All information herein is provided as a courtesy for Haas machine owners
for reference and illustrative purposes only. Haas Automation cannot be held
responsible for repairs you perform. Only those services and repairs that are
provided by authorized Haas Factory Outlet distributors are guaranteed.
Only an authorized Haas Factory Outlet distributor should service or repair a
Haas machine that is protected by the original factory warranty. Servicing by
VMC
Troubleshooting
SERVICE MANUAL
SERVICE TROUBLE
TROUBLESHOOTING
This section is intended for use in determining the solution to a known problem. Solutions given are
intended to give the individual servicing the CNC a pattern to follow in, first, determining the problems
source and, second, solving the problem.
The troubleshooting tips are organized in this section according to the area of the CNC that may be
giving sign of a problem. (Ex.: Out-of round circles in drilling will be found under the heading General
Machine Operation - Accuracy).
If the problem you are experiencing cannot be found under the heading you expect, please try
several other possible headings. If the problem is still not found, contact Haas Automation for further
details.
BEFORE YOU BEGIN:
l USE COMMON SENSE
Many problems are easily overcome by correctly evaluating the situation. All machine opera
tions are composed of a program, tools, and tooling. You must look at all three before blaming
one as the fault area. If a bored hole is chattering because of an overextended boring bar, dont
expect the machine to correct the fault. Dont suspect machine accuracy if the vise bends the
part. Dont claim hole mis-positioning if you dont first center-drill the hole.
l FIND THE PROBLEM FIRST
Many mechanics tear into things before they understand the problem, hoping that it will appear
as they go. We know this from the fact that more than half of all warranty returned parts are in
good working order. If the spindle doesnt turn, remember that the spindle is connected to the
gear box, which is connected to the spindle motor, which is driven by the spindle drive, which
is connected to the I/O BOARD, which is driven by the computer. The moral here is dont
replace the spindle drive if the belt is broken. Find the problem first; dont just replace the
easiest part to get to.
l DONT TINKER WITH THE MACHINE
There are hundreds of parameters, wires, switches, etc., that you can change in this machine.
Dont start randomly changing parts and parameters. Remember, there is a good chance that if
you change something, you will incorrectly install it or break something else in the process.
Consider for a moment changing the processors board. First, you have to download all param
eters, remove a dozen connectors, replace the board, reload and reconnect, and if you make
one mistake or bend one tiny pin it WONT WORK. You always need to consider the risk of
accidentally damaging the machine anytime you work on it. It is cheap insurance to doublecheck a suspect part before physically changing it. The less work you do on the machine the
better.
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SERVICE MANUAL
G
eneral Machine Operation
1. GENERAL MACHINE OPERATION
1.1 MACHINE NOT RUNNING
´ Machine cannot be powered on.
l Check input voltage to machine (Section 2,Electrical Service).
l Check main circuit breaker at top right of electrical cabinet; switch must be at the on position.
l Check overvoltage fuses (Section 3.1,Electrical Service).
l Check wiring to POWER OFF button on front control panel.
l Check wiring to AUTO OFF relay to IOPCB.
l Replace IOPCB (Section 4.3, ElectricalService).
l Replace POWER PCB (Section 4.4 Electrical Service).
´ Machine can be powered on, but turns off by itself.
l Check settings #1 and #2 for Auto Off Timer or Off at M30.
l Check alarm history for OVERVOLTAGE or OVERHEAT shutdown.
l Check AC power supply lines for intermittent supply.
l Check wiring to POWER OFF button on front control panel.
l Replace IOPCB (Section 4.3, Electrical Service).
l Check Parameter 57 for Power Off at E-STOP.
l Replace MOTIF PCB (Section 4.1, Electrical Service).
´ Machine turns on, keyboard beeps, but no CRT display.
l Check for green POWER LED at front of CRT.
l Check for power connections to CRT from IOPCB.
l Check video cable (760) from VIDEO PCB to CRT.
l Replace CRT (Section 5.1, Electrical Service).
´ Any LED on Microprocessor PCB goes out (except HALT).
l Replace Microprocessor PCB (Section 4.1, Electrical Service).
l Replace VIDEO PCB (Section 4.1, ElectricalService).
l Replace MOTIF PCB (Section 4.1, Electrical Service).
´ Machine turns on, CRT works, but no keyboard keys work.
l Check keyboard cable (700) from VIDEO to KBIF PCB.
l Replace keypad (Section 5.5, Electrical Service).
l Replace KBIF PCB (Section 4.6, Electrical Service).
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Vibration
1.2 VIBRATION
Vibration is a subjective evaluation with perceptions varying among individuals, making it difficult to
determine in mild cases if there is an actual problem. Because the VF Series uses a gear head, it will
be noisier than a direct drive or belt system. In obvious cases, it is a matter of determining the source
_ which is not easy, since all parts rotate together and sound can be transferred readily. Vibrations also
need to be distinguished from noise such as a bad bearing. We will assume that vibrations would be
something that could be felt by putting your hand on the spindle covers. One crude method of measurement would be to take an indicator on a magnetic base extended 10 inches between the table and
spindle housing and observe the reading of the indicator. A reading of more than .001 would indicate
excessive vibration. The two common sources of noise are the spindle and axis drives. Most complaints about vibration, accuracy, and finish can be attributed to incorrect machining practices such as
poor quality or damaged tooling, incorrect speeds or feeds, or poor fixturing. Before concluding that
the machine is not working properly, ensure that good machining practices are being observed. These
symptoms will not occur individually (Ex. A machine with backlash may vibrate heavily, yielding a bad
finish.). Put all of the symptoms together to arrive at an accurate picture of the problem.
´ Machine vibrates while spindle is on and is not cutting. Sometimes only at
specific RPM.
l If the spindle alone causes vibration of the machine this is usually caused by the belt/pulley
drive system. This occurs because a pulley is either out of balance, misaligned, or belt tension
is incorrect. It is extremely important that when servicing the spindle transmission that pulleys
are checked for runout. Balance is almost impossible to check except by trial and error. This
method can be accomplished by putting additional washers under one of the allen bolts of
the locking collar and observing the effect. By moving from bolt to bolt you should see better or
worse results and take action accordingly. Vibrations at different speeds are usually caused
by all of the above except that harmonics are in play. If the problem is severe and cannot
simply be corrected, you may have to consider replacing the gearbox and spindle with factorybalanced units.
SERVICE MANUAL
SERVICE TROUBLE
´ Machine vibrates while jogging the axis with the hand wheel.
l The HAAS control uses very high gain accelerations curves. This vibration as you jog is simply
the servos quickly trying to follow the handle divisions. If this is a problem, try using a smaller
division on the handle. You will notice the vibration more at individual clicks than when you are
turning the handle faster. This is normal.
´ The machine vibrates excessively in a cut.
l This is a tough one to call because machining practices come into play. Generally speaking, the
least rigid element of a cut is the tool because it is the smallest part. Any cutter will vibrate if
pushed beyond its tensile strength. In order to eliminate the machine as the source of the
problem, you need to check the spindle and the backlash of the axes as described in the
following sections. Once machining practices have been eliminated as the source of vibration,
observe the machine in both operation and cutting air. Move the axes (individually) without
the spindle turning and then turn the spindle without moving the axes. Isolate whether the
vibration comes from the headstock or from an axis. Isolate the source of vibration per Sec
tions 2.2, 3.2, and Section 6.
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1.3 ACCURACY
Before you complain of an accuracy problem, please make sure you follow these simple dos
and donts.
l Dont ever use a wiggler test indicator for linear dimensions. They measure in an arc and have
sine/cosine errors over larger distances.
l Dont use magnetic bases as accurate test stops. The high accel/decel of the axis can cause
them to move.
l Dont attach test points to the sheet metal of the spindle head or table.
l Dont check for thermal growth with an indicator on a long extension magnetic base.
l Do insure that test indicators and stops are absolutely rigid and mounted to machined casting
surfaces.
l Do check a suspected error with another indicator or method for verification.
l Do ensure that the indicator is parallel to the axis being checked to avoid tangential reading
errors.
l Do center drill holes before using jobber length drills if accuracy is questioned.
l Once machining practices have been eliminated as the source of the problem, determine
specifically what the machine is doing wrong.
Accuracy
´ Machine will not interpolate a round hole.
l Check the levelness of the machine (See the Installation Manual).
l Check for backlash (Section 3.3).
´ Bored holes do not go straight through the workpiece.
l Check the levelness of the machine (See the Installation Manual).
l Check for squareness in the Z axis.
´ Machine bores holes out-of-round.
l Check the levelness of the machine (See the Installation Manual).
l Check the sweep of the machine (Section 5.3, Mechanical Service).
´ Bored holes are out of round, or you bore a hole at a given X/Y position and then
check at the same location using a test indicator and it indicates you are out of
position.
l The spindle is not parallel to the Z axis. Check the spindle sweep to the table and the
squareness of the Z axis with a cylinder square. If available use a spindle master bar and
indicate the spindle to the Z axis.
´ Machine mis-positions holes.
l Check the levelness of the machine (See the Installation Manual).
l Check for backlash (Section 3.3).
l Check the squareness of the X axis to the Y axis.
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Finish
´ Machine leaves large steps when using a shell mill.
l Check the levelness of the machine (See the Installation Manual).
l Check the sweep of the machine (Section 5.3, Mechanical Service).
l Cutter diameter too large for depth of cut.
´ Boring depth inaccurate (VF-6)
Insufficient counterbalance pressure due to:
l Hose corrupted.
l regulator bad.
l check valve bad.
l air cylinder bad.
l bound cylinder
l surge tank leak
1.4 FINISH
SERVICE MANUAL
SERVICE TROUBLE
´ Machining yields a poor finish.
l Check for backlash (Section 3.3).
l Check the condition of the tooling and the spindle (Section 2).
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Spindle
2. SPINDLE
2.1 NOT TURNING
´ Spindle not turning.
l If there are any alarms, see Section 6.
l Check that the spindle turns freely when machine is off.
l If motor turns but spindle does not, see Sections 3 and 9, Mechanical Service.
l Command spindle to turn at 1800 RPM and check spindle drive display. If display blinks bb,
check spindle orientation switch (Section 7, Mechanical Service). If spindle drive does not light
the RUN LED, check forward/reverse commands from IOPCB (Section 4.3, Electrical Service).
l Check the wiring of analog speed command from MOTIF PCB to spindle drive (cable 720).
l If spindle is still not turning, replace MOTIF PCB (Section 4.1, Electrical Service).
l If spindle is still not turning, replace spindle drive (Section 5, Mechanical Service).
l Check for rotation of the gearbox (VF-1, VF-2, VF-3) or the motor (VF-0). If the motor or gearbox
operates, check the drive belt (Section 3, Mechanical Service).
l Disconnect the drive belt. If the spindle will not turn, it is seized and must be replaced (Section
5, Mechanical Service).
NOTE: Before using the replacement spindle, the cause of the previous failure must be deter
mined.
2.2 NOISE
Most noises attributed to the spindle actually lie in the motor/gearbox or drive belt of the ma
chine. Isolate the sources of noise as follows:
´ Excessive noise coming from the spindle head area.
On VF-1, VF-2, and VF-3 models, first determine if the noise is related to the RPM of the motor or the
RPM of the spindle. For example: If the noise appears at 2000 RPM in high gear, listen for a
similar noise at 500 RPM in low gear. If the same noise persists, the problem lies with the
gearbox. If the noise disappears, the problem could be either the gearbox or the spindle, and
further testing is necessary.
l Check the alignment of the pulleys to the belt. Correct as necessary (Sections 3 and 4,
Mechanical Service).
l Remove the head covers and check the machines drive belt tension (Section 3.3, Mechanical
Service).
ØIf the noise persists, turn the drive belt over on the pulleys. If the noise is significantly
different, the belt is at fault. Replace the belt (Section 3, Mechanical Service).
ØIf the noise does not change, remove the belt and go on to the next step.
l Check the pulleys for excessive runout (more than 0.003" axial or radial).
l Run the motor (VF-0) or the gearbox (VF-1, VF-2, VF-3) with the drive belt disconnected. If the
noise persists, the problem lies with the gearbox/motor. If it disappears, go on to the next step.
l Check for the correct amount of lubrication to the spindle bearings (1-2 cc every two hours) in a
an air mist-lubricated spindle.
ØIf the spindle is not getting lubrication, correct the problem per the lube and air dia
gram at the back of this manual and replace the spindle (Section 5,Mechanical Service).
ØIf the spindle is getting lubrication, replace the spindle (Section 5,Mechanical Service).
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Spindle
2.3 OVERHEATING
When investigating complaints of overheating, a temperature probe must be used to accurately
check the temperature at the top of the spindle taper. The temperature displayed in Diagnostics is not
relevant. A machine that runs at high RPM continuously will have a much warmer spindle than a machine that runs at a lower RPM. New spindles tend to run much warmer than spindles that have already been broken in. In order to run a valid test on a new spindle, ensure that it is properly broken in.
To break in a spindle, do the following:
l Run the spindle at 300 RPM for at least two (2) hours.
l Increase the spindle speed to 1000 RPM for 20 minutes.
l Increase the spindle speed to 3000 RPM for 20 minutes.
l Increase the spindle speed to 7000 RPM for 20 minutes.
l Stop the spindle and allow to cool to room temperature.
l Turn the spindle on to 7000 RPM and monitor the temperature inside the spindle taper at 15-
minute intervals until the temperature drops off, then stabilizes. This will take about two
(2)hours.
l Temperatures of about 140
If the spindle fails this test, check the following:
l Check for correct amount of lubrication (1-2 cc every two hours).
o
are possible at the end of this test.
SERVICE MANUAL
SERVICE TROUBLE
NOTE: Over lubrication is a common source of overheating. Check the oil flow carefully.
l Check the drive belt tension (Section 3, Mechanical Service). Too-tight belts will cause heating
of the top bearing in the spindle housing.
l Ensure that the correct oil is being used (Lubrication Chart, page 131).
Spindle Motor Overheat Sense Switch
There is a normally closed thermal switch in the spindle motor. Should the temperature reach 210 F
the switch will trigger an alarm- Spindle Drive Fault.
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SERVICE MANUAL
2.4 STALLING/LOW TORQUE
Generally, complaints of stalling or low torque relate to incorrect tooling or machining practices. A
spindle that is tending to seize will yield a poor finish machining, run very hot and very loud. Investigate machining problems before concluding the problem exists with the spindle or spindle drive.
It is important to consider what horsepower and torque is available in various speed ranges of the
spindle. If your machine is a VF-1 or VF-2 (with a transmission), the following horsepower and torque
are available in low gear:
SPEED (RPM) TORQUE (ft-lb) HORSEPOWER
0-100 45-90 less than 2
100-500 90 3 to 7.5
500-1250 90-35 7.5
1250-1840 35-25 7.5 to 5
If your machine is a VF-0 (no transmission) or a VF-1 or VF-2 and you are in high gear, the following
are available:
Spindle
SPEED (RPM) TORQUE (ft-lb) HORSEPOWER
0-400 11-22 less than 2
400-2000 22 3 to 7.5
2000-5000 22-9 7.5
5000-7500 9-6 7.5 to 5
If your machine is a VF-3, the following horsepower and torque are available in low gear:
SPEED (RPM) TORQUE (ft-lb) HORSEPOWER
0-125 60-120 less than 3
125-625 120 4 to 10
625-1550 120-45 10
1550-1840 45-32 10 to 7
If your machine is a VF-3 and you are in high gear, the following are available:
SPEED (RPM) TORQUE (ft-lb) HORSEPOWER
0-600 15-30 less than 3
600-2500 30 4 to 10
2500-6250 30-11 10
6250-7500 11-9 10 to 7
If you still have spindle torque problems and there is no mechanical cause such as binding or
friction in the transmission or spindle, the motor or spindle drive are the cause. The first choice for
replacement is the spindle drive. If there is still a problem, the entire motor/transmission assembly
must be replaced.
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Spindle
2.5 SPINDLE DRIVE
Low line voltage may prevent the spindle from accelerating properly. If the spindle takes a long
time to accelerate, slows down or stays at a speed below the commanded speed with the load meter
at full load, the spindle drive and motor are overloaded. High load, low voltage, or too fast accel/decel
can cause this problem. See Section 28 for adjustment.
If the spindle is accelerated and decelerated frequently, the regenerative load resistor inside the
control may heat up. If this resistor heats beyond 100oC, a thermostat will generate an overheat
alarm.
If the regen load resistors are not connected or open, this could then result in an overvoltage alarm.
The overvoltage occurs because the regenerative energy being absorbed from the motor while decelerating is turned into voltage by the spindle drive. If this problem occurs, the possible fixes are to slow
the decel rate or reduce the frequency of spindle speed changes.
2.6 ORIENTATION
SERVICE MANUAL
SERVICE TROUBLE
´ Spindle loses correct orientation.
l Check alarm history, looking for spindle overload and axis overcurrent alarms. These alarms
indicate the machine is not being properly operated.
l Check the orientation ring for tightness (Section 7, Mechanical Service). Ensure the shaft on
which the ring mounts is free of grease.
l Check the orientation ring for cracks near the bolt holes or near the balancing holes.
> If there are cracks, replace the ring (Section 7, Mechanical Service).
> If there are no cracks, remove the drive belt (Section 3, Mechanical Service) and verify that
the pulley on the transmission output shaft is tight. On most machines, there is no key on the
transmission pulley.
l Check the shot pin on the gearbox for binding, damage, and proper operation. Replace it if it is
damaged.
l Check the switch on the shot pin against the Diagnostic display. Replace the switch if it is
found to be faulty.
2.7 TOOLS STICKING IN TAPER
´ Tool sticking in the taper causes ATC to be pulled up; accompanied by a popping
noise as the tool holder pops out of the spindle taper.
NOTE: This problem may occur after loading a cold tool into a hot spindle (a result of thermal
expansion of the tool holder inside the spindle taper), or after heavy milling. If sticking only occurs
during these situations, no service is necessary.
l Check the condition of the customers tooling, verifying the taper on the tooling is ground and
not turned. Look for damage to the taper caused by chips in the taper or rough handling. If the tooling
is suspected, try to duplicate the symptoms with different tooling.
l Check the condition of the spindle taper. Look for damage caused by chips or damaged
tooling. Also, look for damage such as deep gouges in the spindle taper caused by tool
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crashing. See Section 5, Mechanical Service, for spindle cartridge replacement.
l Duplicate the cutting conditions under which the deflection occurs, but do not execute an
automatic tool change. Try instead to release the tool using the tool release button on the front
of the spindle head. If sticking is observed, the deflection is not caused by improper ATC
adjustment, but is a problem in the spindle head on the machine. See Section 5, Mechanical
Service, for spindle cartridge replacement.
l Ensure the spindle is not running too hot (Section 2.3).
SERVICE MANUAL
Servos / Leadscrews
3. SERVO MOTORS / LEADSCREWS
There is very little that a user might do to repair a servo motor. Problems with servo motors may
include open-circuited motor, shorted winding of motor, motor shorted to case, water (coolant) in motor,
or overheat damage to motor. None of these can be fixed by the user so the motor must be replaced.
All of the above problems would generate alarms identifying one of the servo motors as having failed.
These alarms are 103-106 (following error too large), 108-111 (servo overload), 135-138 (overheat),
139-142 (Z channel fault), 153-156 (Z channel missing), and 161-164 (overcurrent).
Attached to each DC servo motor, there is an incremental encoder that is 2000 lines per revolution.
These encoders also supply a Z channel pulse once per revolution. The encoders and Z channel are
continuously monitored to ensure the number of pulses matches for each revolution of the motor. If the
encoders become contaminated, these pulse counts will be wrong and an alarm will be generated.
This ensures that the data from the encoders is reliable. There can never be a loss of servo position
due to accumulated encoder errors. The alarms generated will indicate that either the Z pulse occurred
and the encoder pulse was wrong or, after one and one half motor revolutions, the Z pulse did not
occur.
Encoders faults can be caused by contamination of the encoder or by a wiring problem. If the
encoder is contaminated, it must be replaced. Wiring problems may be a broken wire, shorted wire, or
missing shield. All wires to the encoder are enclosed in their own shielded cable. In addition, all
power wires to the motor are enclosed in a separately shielded cable. Failure of either of these shields
may cause noise in the encoder circuits and result in the encoder fault alarms.
Never connect or disconnect the servo motor cables with the control powered as this will cause an
apparent encoder fault.
Servo Characteristics
This machine is not capable of instantly changing speed. That is, it takes some non-zero time to
accelerate and decelerate. Acceleration and deceleration in this machine have both a constant accel/
decel mode and an exponential mode. Constant acceleration is used at the beginning of a rapid move
and at the end of any move whose speed exceeds the exponential accel/decel time constant.
Constant acceleration is a type of motion when the amount of speed change over time is constant.
This constant is set by Parameters 7, 21, 35, and 49. It has units of encoder increments per second
per second.
Exponential acceleration and deceleration is a type of motion where the speed is proportional to the
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Servos / Leadscrews
distance remaining in a programmed travel. The exponential accel/decel time constant is set by Para
meters 113, 114, 115, and 116. It has units of 0.0001 seconds. The speed limit at which exponential
accel/decel is not available is defined by the relationship between Parameters 7 and 113 (for the Xaxis). Thus if Parameter 7 is 1200000 steps/sec/sec and Parameter 113 is 750 (0.075 seconds); the
maximum velocity for accurate interpolation should be:
1200000 x 0.075 = 90000 steps/second
For a 2000 line encoder and 6 mm screw, this would be:
60 x 90000 / 33867 = 159 inches/minute
In the normal feed cutting mode, with G64 active, giving continuous cutter motion, deceleration of
the axes in motion begins at some distance away from the end point. If look-ahead has provided
another motion, the acceleration for that motion will begin at the same instant. This means that two
motions, at right angles to each other, will not produce a perfectly square corner. The corner will be
rounded. It also means that if the two motions are parallel or nearly parallel, there will be a smooth
transition from one stroke to the next.
Rapid moves have a slightly different operation when continuous cutter mode is active. Acceleration for the next motion is started when the axes being moved all fall within the In Position Limit Parameters 101, 102, 103, and 104. These parameters have units of encoder steps. Rapid moves will
also decelerate at the constant accel/decel limit until the speed drops below that for exponential accel/
decel (see example above giving 159 inches per minute). Parameter 57 can be used to override this.
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SERVICE TROUBLE
To prevent the rounding of corners, you can specify exact stop either with G09 (non-modal) or with
G61 (modal). When either of these is active in a motion, all of the axes are brought to an exact stop, at
zero speed, before the next motion is started.
The tool path in a circular move (G02 or G03) is not changed by the exponential acceleration/
deceleration so there is no error introduced in the radius of the cut unless the speed exceeds that for
exponential accel/decel (see example above giving 159 inches per minute).
The servo motor encoders are differential line drivers. This means that the A, B, and Z signals are
transmitted to the control as signal pairs. A cable test is performed on these signals to ensure the
differential pair are always present.
Overheat Sense Switches
Each servo motor contains a normally-open overtemperature sense thermostat. When the motor
case temperature exceeds 150° F, an alarm will be generated and operation of the machine will stop.
This alarm should not occur under any normal operating circumstances and usually indicates that there
is serious problem with the motor or drive circuit. After September 1990, the overheat sensor was
changed to normally closed. This change is specified in the parameters.
Overcurrent Sensor
Each servo motor drive circuit contains a current limit setting and an overcurrent sense circuit.
When an overcurrent condition persists for more than 0.01 second, an alarm will be generated and
operation of the machine will stop. This current limit is presently set at 20 amps.
Ground Fault Detector
This control has a ground fault sense circuit added to the servo drive power supply. This circuit will
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detect a short to ground on any of the servo motor power leads or in the internal 115V AC power. A
ground fault can be caused by arcing brushes in the servo motors and will shut off all servo power.
3.1 NOT OPERATING
All problems that are caused by servo motor failures should also register an alarm. Check the
alarm history to determine the problems cause before any action is taken.
´ Servo motor is not functioning.
l Check the power cable from rear electrical cabinet to ensure connection is tight.
l Encoder is faulty or contaminated (Alarms 139-142, 153-156, 165-168, 182-185). Replace motor
assembly (Section 10, Mechanical Service).
l Open circuit in motor (Alarms 139-142, 153-156, 182-185). Replace motor assembly (Section
10 , Mechanical Service).
l Motor has overheated, resulting in damage to the interior components (Alarms 135-138, 176).
Replace motor assembly (Section 10, Mechanical Service).
l Wiring is broken, shorted, or missing shield (Alarms 153-156, 175, 182-185).
l Dust in the motor from brushes has shorted out the motor (Alarms 153-156, 175, 182-185).
Replace motor assembly (Section 10, Mechanical Service).
l Motor has overheated; no damage to the interior components. OVERHEAT alarm has been
triggered. After thorough check of motor (DO NOT DISASSEMBLE!), take necessary steps to
eliminate the problem and alarm to resume operation. If motor is still inoperable, replace motor
assembly (Section 10, Mechanical Service).
l Check for broken or loose coupling between the servo motor and the lead screw. Replace or
repair the coupling (Section 10.4, Mechanical Service)
l Check for a broken lead screw. If cracked or broken, replace (Section 10, Mechanical Service).
Servos / Leadscrews
NOTE: If a lead screw fails, it is most often due to a failed bearing sleeve. When replacing the lead
screw in an older machine, always replace the bearing sleeve with the current angular contact
bearing sleeve (Section 12, Mechanical Service).
3.2 NOISE
Lead screw noise is usually caused by a lack of lubrication and is usually accompanied by heating. Other causes are misalignment, bearing sleeve damage, or ball nut damage. Check the alarm
history of the machine and look for axis overcurrent and following error alarms.
NOTE: Do not replace lead screws or bearing sleeves without due consideration; they are extremely durable and reliable. Verify that customer complaints are not due to tooling, programming, or
fixturing problems.
´ Servo motor noise.
l Disconnect the servo motor from the lead screw and rotate by hand. If the noise persists,
replace the motor assembly (Section 10, Mechanical Service).
l Noise is caused by motor brushes. No problems will occur and noise should eventually go
away.
l Noise is caused by bearings. Rolling, grinding sound is heard coming from the motor. EN
SURE NOISE IS NOT COMING FROM THE BRUSHES. If bearings are making a consistently
loud sound, replace the bearing sleeve (Section 12, Mechanical Service).
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´ Lead screw noise.
l Ensure oil is getting to the lead screw through the lubrication system (See Air and Oil Diagrams,
pages 129 & 130). Look for a plugged metering valve.
l Check for damage to the bearing sleeve.
l Check the pre-load on old-style bearing sleeves (Section 12, Mechanical Service).
NOTE: The current angular contact design sleeve has a fixed pre-load; it cannot be adjusted.
l Run the axis back and forth. The motor will get very hot if the bearing sleeve is damaged. If
so, turn the axis by hand and feel for roughness in the lead screw. Loosen the clamp nuts at
both ends of the lead screw. If the symptom disappears, replace the bearing sleeve (Section
12, Mechanical Service). Be certain to check for damage to the lead screw shaft where the
bearing sleeve is mounted.
Ø If the noise persists, the lead screw is damaged and must be replaced (Section 11, Mechani
cal Service). When replacing the lead screw in an older machine, always replace the bearing
sleeve with the current angular contact design bearing sleeve (Section 12, Mechanical Service).
l Check the lead screw for misalignment. If incorrect, align as outlined in Section 11, Mechanical
Service.
SERVICE MANUAL
SERVICE TROUBLE
Misalignment in the lead screw itself will tend to cause the lead screw to tighten up and make
excessive noise at both ends of the travel. The ballnut may get hot. Misalignment radially at the yoke
where the lead screw ball nut mounts is indicated by heating up of the ball nut on the lead screw, and
noise and tightness throughout the travel of the lead screw. Misalignment at the yoke where the ball nut
mounts is indicated by noise and tightness at both ends of the travel of the lead screw. The ball nut
may get hot.
´ Noise in Z - Motion (VF-6)
l Brake won't release (leadscrew won't rotate)
Ø alarm not cleared
Ø low pressure switch blown
Ø brake power fuse blown
Ø brake power transformer blown
Ø brake power rectifier blown
Ø cabling pinched
Ø brake failed
3.3 ACCURACY/BACKLASH
Accuracy complaints are usually related to tooling, programming, or fixturing problems. Eliminate
these possibilities before working on the machine.
´ Poor mill table-positioning accuracy.
l Check for a loose encoder on the servo motor. Also, ensure the key in the motor or the
lead screw is in place and the coupling is tight (Sections 10, 11, Mechanical Service).
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l Check for backlash in the lead screw as outlined below:
SERVICE MANUAL
INITIAL PREPARATION -
Turn the VMC ON. ZERO RET the machine and move the mill table to the approximate center of its
travel in the X and Y directions. Move the spindle head to approximate center of the Z-axis travel, also.
CHECKING X-AXIS:
1. Set up a dial indicator and base on the mill table as shown in Fig. 3-1.
Servos / Leadscrews
Fig. 3-1 Dial indicator in position to check X-axis.
2. Set dial indicator and the Distance to go display in the HANDLE JOG mode to zero as fol
lows: - Zero the dial indicator. - Press the MDI button on the control panel. - Press the HANDLE
JOG button on the control panel. The Distance to go display on the lower right hand corner
should read: X=0 Y=0 Z=0
3. Set the rate of travel to .001 on the control panel and jog the machine .010 in the positive (+) X
direction. Jog back to zero (0) on the display. The dial indicator should read zero (0) ± .0001.
4. Repeat step three in the negative (-) direction.
TOTAL DEVIATION BETWEEN THE DIAL INDICATOR AND THE CONTROL PANEL DISPLAY
SHOULD NOT EXCEED .0002.
An alternate method for checking backlash is to place the dial indicator as shown in Fig. 3-1 and
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Servos / Leadscrews
manually push on the mill table in both directions. The dial indicator should return to zero after releasing
the table. NOTE: The servos must be on to check backlash by this method.
CHECKING Y-AXIS:
1. Set up a dial indicator and base on the mill table as shown in Fig. 3-2.
SERVICE MANUAL
SERVICE TROUBLE
Fig. 3-2 Dial indicator in position to check Y-axis.
2. Set dial indicator and the Distance to go display in the HANDLE JOG mode to zero as fol
lows: - Zero the dial indicator. - Press the MDI button on the control panel. - Press the HANDLE
JOG button on the control panel. The Distance to go display on the lower right hand corner
should read: X=0 Y=0 Z=0
3. Set the rate of travel to .001 on the control panel and jog the machine .010 in the positive (+) Y
direction. Jog back to zero (0) on the display. The dial indicator should read zero (0) ± .0001.
4. Repeat step three in the negative (-) direction.
TOTAL DEVIATION BETWEEN THE DIAL INDICATOR AND THE CONTROL PANEL DISPLAY
SHOULD NOT EXCEED .0002.
An alternate method for checking backlash is to place the dial indicator as shown in Fig. 3-2 and
manually push on the mill table in both directions. The dial indicator should return to zero after releasing
the table.
NOTE: The servos must be on to check backlash by this method.
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SERVICE MANUAL
CHECKING Z-AXIS:
1. Set up a dial indicator and base on the mill table as shown in Fig. 3-3.
2. Manually push up and down on the spindle head while listening for a clunk. Also, watch for any
rapid change in the dial indicator. Either of these indicate possible backlash.
NOTE: Servos must be on to check for backlash in the Z-axis.
NOTE: Do not mistake deflection for backlash in the system.
Servos / Leadscrews
Fig. 3-3 Dial indicator in position to check Z-axis.
> If backlash is found in the system, check for the following possible causes:
l Loose SHCS attaching the ball nut to the nut housing. Tighten the SHCS as described in
Section 11, Mechanical Service.
l Loose SHCS attaching the nut housing to the mill table, spindle head, or saddle, depending on
the axis. Tighten the SHCS as described in Section 11, Mechanical Service.
l Loose clamp nut on the bearing sleeve. Tighten the SHCS on the clamp nut.
l Loose motor coupling. Tighten as described in Section 10.4, Mechanical Service.
l Broken or loose flex plates on the motor coupling. (NOTE: The coupling cannot be serviced in
the field and must be replaced as a unit if it is found to be defective. See Section 10.4, Mechani
cal Service.)
l Loose SHCS attaching the bearing sleeve to the motor housing. Tighten as described in Sec
tion12, Mechanical Service.
l Defective thrust bearings in the bearing sleeve. Replace the bearing sleeve as outlined in
Section 12, Mechanical Service.
l Loose SHCS attaching the axis motor to the motor housing. If the SHCS are found to be loose,
inspect the motor for damage and if none is found, tighten as described in Section 10, Mechani
cal Service. If damage is found, replace the motor (Section 10, Mechanical Service.)
l Incorrect backlash compensation number in the parameter in the machine. Check Parameters
13, 27, and 41.
l Worn lead screw. Replace as outlined in Section 11, Mechanical Service.
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Servos / Leadscrews
3.4 VIBRATION
´ Excessive servo motor vibration.
l If no A axis is present, swap the suspected bad servo motor with the A driver and check to
see if there is a driver problem. If needed, replace the DRIVER PCB (Section 4.2, Electrical
Service).
l Check all Parameters of the suspected axis against the Parameters as shipped with the ma
chine. If there are any differences, correct those and determine how the Parameters were
changed. PARAMETER LOCK should normally be on.
l A bad motor can cause vibration if there is an open or short in the motor. A short would normally
cause a GROUND FAULT or OVERCURRENT alarm; check the ALARMS. An ohmmeter
applied to the motor leads should show between 1 and 3 ohms between leads, and over 1 me
gohm from leads to chassis. If the motor is open or shorted, replace (Section 10, Mechanical
Service).
3.5 OVERHEATING
´ Servo motor overheating.
l If a motor OVERHEAT alarm occurs (ALARMS 135-138), check the Parameters for an incorrect
setting. Axis flags in Parameters 1, 15, or 29 can invert the overheat switch (OVER TEMP NC).
l If the motor is actually getting hot to the touch, there is excessive load on the motor. Check the
users application for excessive load or high duty cycle. Check the lead screw for binding
(Section 3.3). If the motor is binding by itself, replace (Section 10, Mechanical Service).
SERVICE MANUAL
SERVICE TROUBLE
3.6 FOLLOWING ERROR
´ Following error alarms occur on one or more axes sporadically.
l Check DC bus voltage on diagnostics page #2. If it is at the low side of the recommended
voltages, change the transformer tap to the next lower voltage group as explained in the Installa
tion Manual.
l Check motor wiring.
l Replace driver card (Section 4.2, Electrical Service).
l Replace servo motor (Section 10, Mechanical
´ Z-axis motor overcurrent (VF-6)
l Brake won't release (leadscrew won't rotate)
Ø alarm not cleared
Ø low pressure switch blown
Ø brake power fuse blown
Ø brake power transformer blown
Ø brake power rectifier blown
Ø cabling pinched
Ø brake failed
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SERVICE MANUAL
Tool Changer
4. AUTOMATIC TOOL CHANGER
4.1 DEFLECTION
Deflection is usually caused by ATC misalignment, and sometimes caused by damaged or
poor quality tooling, a damaged spindle taper, or a damaged drawbar. Before beginning any troubleshooting, observe the direction of the ATC deflection.
´ During a tool change, ATC appears to be pushed down.
l Check to see if pull studs on the tool holder are correct and tight.
l Check the adjustment of the Z offset (Parameter 64, section 8, Mechanical Service).
NOTE: If the offset is incorrect a tool changer crash has occured and a thorough inspection of the
ATC is necessary at this time.
l Check the adjustment of the Z offset check parameters 71, 72, and 143 against the values
that are in the documentation sent with the machine.
l Ensure the tool holders are held firmly in place by the extractor forks.
l Ensure the balls on the drawbar move freely in the holes in the drawbar when the tool release
button is pressed. If they do not move freely, the a ATC will be pushed down about 1/4" before
the tool holder is seated in the taper, resulting in damage to the roller bolts on the ATC
shuttle. Replace the drawbar. (Section 5.3, Mechanical Service)
´ Tool holder sticking in the spindle taper causes the ATC to be pulled up as the
spindle head is traveling up after depositing the tool holder in the carousel; ac
companied by a popping noise as the tool holder pops out of the spindle taper.
NOTE: This problem may occur after loading a cold tool into a hot spindle (a result of thermal
expansion of the tool holder inside the spindle taper), or after heavy milling. If sticking occurs only
during these circumstances, no service is necessary.
l Check the condition of the customers tooling, verifying the taper on the tool holder is ground
and not turned. Look for damage to the taper caused by chips in the taper or rough handling.
If the tooling is suspected, try to duplicate the symptoms with different tooling.
l Check the condition of the spindle taper. Look for damage caused by chips or damaged
tooling. Also, look for damage such as deep gouges in the spindle taper caused by tool
crashing. See Section 5, Mechanical Service, for spindle cartridge replacement.
l Duplicate the cutting conditions under which the deflection occurs, but do not execute an auto
matic tool change. Try instead to release the tool using the tool release button on the front of the
spindle head. If sticking is observed, the deflection is not caused by improper ATC adjustment,
but is a problem in the spindle head on the machine. See Section 5, Mechanical Service, for
spindle cartridge replacement.
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Tool Changer
´ During a tool change, ATC appears to be pulled up; no popping noises.
l Check the adjustment of the Z offset (Parameter 64, Section 8, Mechanical Service). NOTE: If
the offset is incorrect, a tool changer crash has occurred, and a thorough inspection of the ATC
is necessary at this time.
l Ensure the roller bolts on the shuttle of the ATC are tight against the v-guides on the ATC
holding arm. If the lower right roller bolt is loose against the v-guide, the upper right bolt is
probably bent. See the following section (ATC Crashing) or Section 14.2, Mechanical Service,
for roller bolt replacement. NOTE: Bent roller bolts are a symptom of another problem with the
ATC. Repair the bent roller bolt and then isolate the ATC problem.
l Check Parameter 71 against the values that are in the documentation sent with the machine.
l Ensure the balls on the drawbar move freely in the holes in the drawbar when the tool release
button is pressed. If they do not move freely, the ATC will be pushed down about ¼ before the
tool holder is seated in the taper, resulting in damage to the roller bolts on the ATC shuttle.
Replace drawbar (Section 5.3, Mechanical Service).
´ Tool holders twist against extractor fork during a tool change.
l Check the alignment of the ATC in the X and Y axes (Section 14.3, Mechanical Service).
SERVICE MANUAL
SERVICE TROUBLE
´ Tool holders spin at all pockets of the ATC when the ATC shuttle retracts.
l ATC is misaligned in the Y axis. Realign ATC (Section 14.3, Mechanical Service). NOTE:
Observe the direction the tool holder rotates, as this will be the direction in which the Y axis of
the ATC needs to be moved.
´ Tool holders spin only at certain pockets of the ATC when the ATC shuttle
retracts.
l Check all the extractor forks to ensure they are centered in the pocket of the ATC. Also, see
above. See Section 14.6, Mechanical Service, for extractor fork replacement.
NOTE: If the ATC shows the problem as described here, each extractor fork must be checked and
centered to eliminate the possibility of the ATC being aligned against an incorrectly-centered fork.
4.2 CRASHING
Crashing of the ATC is usually a result of operator error. The most common ATC crashes are
outlined as follows:
´ Shuttle crashes into spindle when a tool change is commanded (tool holder is in
the pocket facing the spindle head).
l Rotate the carousel to an empty pocket. Refer to the Programming and Operation manual for
correct operation.
NOTE: This crash is fairly common and is a result of operator error. If the ATC is stopped in the
middle of tool change cycle, the operator must command the ATC to an empty pocket before the
machine will operate correctly. Repeated crashes of this type can damage the I/O board, the slip
clutch, and the shuttle motor in the ATC.
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SERVICE MANUAL
´ Spindle crashes into top of the tool holder after a turret rotation during a tool
change.
When the spindle head moves down over the top of the tool holder during a tool change, the pull
stud will bind inside the drawbar bore of the spindle, forcing the ATC down, bending the upper right
roller bolt on the ATC shuttle or completely breaking it off. Tool holder is not held correctly in the extractor fork, possibly held only in one side of the extractor and at an odd angle.
l Check all of the extractor forks on the ATC. Replace, if needed (Section 14.6, Mechanical
Service).
´ Spindle crashes into top of the tool holder after a turret rotation during a tool
change.
The balls in the drawbar do not move freely, causing the ATC to be forced down far enough to bend
the upper right roller bolt or completely break it off.
l Ensure the balls on the drawbar move freely in the holes in the drawbar when the tool release
button is pressed. If this failure occurs, check all of the extractor forks on the ATC for damage
and repair the spindle drawbar. See Section 14.1 for ATC shuttle replacement, Section 5.3,
Mechanical Service, for drawbar replacement, and 14.2, Mechanical Service, for extractor fork
replacement.
Tool Changer
´ ATC properly deposits a tool holder in the spindle, but the tools are dropped onto
the machine table when the shuttle retracts.
l Inspect the balls and the Belleville springs in the drawbar. See Section 5.3, Mechanical Service,
for drawbar replacement.
´ The part or fixture on the mill table crashes into long tooling or into the ATC
itself during a tool change.
l Program the machine to move the part out of the way of the ATC. Inspect the pocket involved in
the crash for damage and replace parts as necessary.
´ The part or fixture on the mill table crashes into long tooling or into the ATC
itself when machining.
l Either reposition the tools to remove the interference, or program the carousel to rotate long
tooling out of the way of the part (USE THIS ONLY AS A LAST RESORT). CAUTION! If the carou
sel has to be programmed to rotate long tools clear of the part, the correct carousel position
must be programmed back in before a tool change can be executed. NOTE: If these crashes
occur, thoroughly inspect the ATC for damage. Pay close attention to the extractor forks, the
sliding covers on the ATC carousel, and the roller bolts on the ATC shuttle. See Section 14.2,
Mechanical Service for extractor fork replacement and Section 14.7, Mechanical Service, for
sliding door replacement.
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Tool Changer
4.3 BREAKAGE
Breakage of the ATC is caused by either very hard or repeated crashes.
´ ATC shuttle is broken off of the holding plate.
l Carefully inspect the bosses on the shuttle casting (where the roller bolts mount) for damage to
the threads or cracks. If any of the bosses are cracked, replace the casting. Realign the tool
changer after repairing the machine (Section 14, Mechanical Service).
´ ATC extractor forks are damaged after breakage.
l Check the condition of the mounting holes in the carousel. If the threads are damaged, they
must be repaired or the carousel replaced. See Section 14.6, Mechanical Service, for extractor
fork replacement.
SERVICE MANUAL
SERVICE TROUBLE
4.4 NOISY OPERATION
To isolate noise(s) in the ATC, carefully observe the ATC in operation and look for the following:
´ ATC makes noise as the shuttle moves.
l Check the adjustment of the roller bolts on the ATC (Section 14.2, Mechanical Service). Loose
roller bolts can cause the ATC to make a clunking noise when the shuttle is commanded to
move. Tight roller bolts can cause the shuttle motor to labor excessively, possibly damaging
the motor or the I/O board. In this case, the shuttle may also move too slowly.
l Check for damage to the trap door on the ATC cover. See Section 14.11, Mechanical Service,
for trap door replacement.
l Check for missing plastic riders on the ATC shutter. See Section 14.11, Mechanical Service, for
shutter replacement.
l Ensure the guide pin mounted to the holding plate is not bent and does not scrape the ATC
cover during movement. See Section 14.11, Mechanical service, for guide pin replacement.
l Listen for damage to the gear train in the shuttle motor. If the motor is found to be the source of
the noise, replace the motor (Section 14.8, Mechanical Service). DO NOT try to repair the motor
or to further isolate the noise in the motor. ATC makes noise during carousel rotation.
l Check to ensure the Geneva driver on the turret motor is tight and properly adjusted (Section
14.8, Mechanical Service). If the Geneva driver is found to be loose, check for damage to the
Geneva star. Any roughness in the slots will require that it be replaced (Section 14.10, Mechani
cal Service).
l Check the adjustment of the Geneva driver in relation to the Geneva star (Section 14.10, Me
chanical Service). If the adjustment is too loose, the carousel will vibrate heavily and make a
loud clanking noise during carousel rotation. If the adjustment is too tight, the turret motor will
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labor excessively and the carousel may appear to move erratically. NOTE: If the turret motor
adjustment is tight for extended periods, the turret motor, Geneva star, and the I/O board may
be damaged. If the adjustment of the Geneva star appears tight at some pockets and loose at
others, the problem lies with the Geneva star. Check the concentricity of the star relative to the
bearing housing on the carousel assembly. If the concentricity of the star is proven to within
specification and the problem still persists, the Geneva star must be replaced (Section 14.10,
Mechanical Service).
Ensure the screws holding the turret motor to the mounting plate are tight (Section 14.9,
Mechanical Service).
l Ensure the screws attaching the motor mounting plate to the shuttle casting are tight.
l Check for excessive noise in the gear train of the turret motor. See Section 14.9, Mechanical
Service, for turret motor replacement.
NOTE: If the motor is found to be the source of noise, replace the motor assembly (motor, mounting
plate, and Geneva driver).
DO NOT attempt to repair the motor or to further isolate the problem in the motor.
SERVICE MANUAL
Tool Changer
4.5 SPINDLE ORIENTATION
A switch is used to sense when the pin drops in to lock the spindle. When the pin drops the switch
opens, indicating orientation is complete. The normally-closed side of this switch is wired to the spindle
drive and commands it into the COAST STOP condition. This is done to make sure that the spindle
motor is not powered when the pin is locking the spindle. If, during a tool change, the dogs on the
spindle shaft do not align with the keys on the ATC carousel, the spindle orientation may be at fault.
The orientation of the spindle is as follows:
1) If the spindle is turning, it is commanded to stop,
2) Pause until spindle is stopped,
3) Spindle orientation speed is commanded forward,
4) Pause until spindle is at orientation speed,
5) Command spindle lock air solenoid active,
6) Pause until spindle locked status is active and stable,
7) If not locked after time-out time, alarm and stop.
´ ATC out of orientation with the spindle. Incorrect spindle orientation will cause
the ATC to crash as the shuttle moves. Alarm 113 will be generated.
l Check the orientation of the machine (Section 7, Mechanical Service).
´ ATC WILL NOT RUN
In all cases where the tool changer will not run, an alarm is generated to indicate either a shuttle
in/out problem or a turret rotation problem. These alarms will occur either on an attempt to change tools
(ATC FWD) or ZERO RETURN the machine (AUTO ALL AXES). Use the appropriate alarm to select one
of the problems following:
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Tool Changer
´ ATC shuttle will not move; shuttle is getting power (Command a tool change and
feel for power being applied to the shuttle motor).
l Disconnect the slip clutch arm from the ATC shuttle and ensure the shuttle can move
freely. If not, see Sections 14.1, 14.3, and 14.4, Mechanical Service, for shuttle adjustment.
l Command a tool change with the shuttle disconnected.
Ø If the shuttle cycles, check the slip clutch on the ATC. See Section 14.8, Mechanical Service,
for slip clutch replacement.
NOTE: The slip clutch should move the shuttle with a fair amount of force, but not so much that the
shuttle cannot be made to slip when holding it back by hand. If the slip clutch is frozen, replace it. It
cannot be rebuilt in the field.
Ø If the shuttle does not cycle, the motor has failed and must be replaced. Turn the motor by
hand and feel for binding in the gear train in the motor. See Section 14.8, Mechanical Service.
NOTE: The motor uses a large amount of gear reduction and should be hard to turn by hand.
SERVICE MANUAL
SERVICE TROUBLE
´ ATC shuttle will not move; shuttle is not getting power (Command a tool change
and feel for power being applied to the shuttle motor).
l Check that the TC IN/TC OUT LED on the I/O PCB is illuminated when a tool change takes
place.
Ø If the LED lights, check the fuse FU5 on the POWER PCB. Otherwise, replace the I/O PCB
(Section 4.3, Electrical Service).
Ø If the LED does not light, check cables 510 and 520.
´ ATC turret will not rotate; turret motor is getting power (command a tool change
and feel for power being applied to the turret motor).
l If power is applied but the output shaft on the motor does not turn, check for binding between
the turret motor assembly and the Geneva star (Section 14.9, Mechanical Service). Check for
damage to the Geneva star or the Geneva driver. See Section 14.10, Mechanical Service, for
Geneva star replacement, and 14.9 for turret motor replacement. Check for a broken turret
motor (See Section 14.9, Mechanical Service for turret motor replacement). NOTE: Do not at
tempt to repair the motor or to further isolate the problem in the motor.
´ ATC turret will not rotate; turret motor is not getting power (command a tool
change and feel for power being applied to the turret motor).
l Check that the TC CW/ TC CCW LED on the I/O PCB is illuminated when a tool change takes
place.
Ø If the LED lights, check the fuse FU5 on the POWER PCB. Otherwise, replace the I/O PCB
(Section 4.3, Electrical Service).
Ø If the LED does not light, check cables 510 and 520.
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SERVICE MANUAL
Gearbox / Spindle Motor
5. GEARBOX AND SPINDLE MOTOR
The gearbox cannot be serviced in the field and must be replaced as a unit. NEVER remove a
motor from a VF-1, VF-2, or VF-3 gearbox as this will damage the gearbox and void the warranty.
5.1 NOISE
When investigating complaints of gearbox noise, also refer to Section 2 (Spindle Troubleshooting).
Gearboxes can be damaged by failed air solenoids, gearshift cylinders, or bearings, resulting in noisy
operation. It is not likely that poor finish on a workpiece can be attributed to a bad gearbox.
´ Excessive or unusual noise coming from the gearbox and/or spindle motor.
Operate the machine in both high and lowgears. Monitor the gearbox for noise
in both gear positions and if the pitch of the noise varies with the motor or the output shaft
speed.
Ø If the noise only occurs in one gear throughout the entire RPM range of that gear position, the
problem lies with the gearbox, and it must be replaced (Section 9, Mechanical Service).
Ø If the noise occurs in both gear positions, disconnect the drive belt and repeat theprevious
step. If the noise persists, the gearbox is damaged and must be replaced, (Section 9, Me
chanical Service).
Ø With the drive belt disconnected, run the machine at 1000 RPM in high gear. Command a
change of direction and listen for a banging noise in the gearbox as the machine slows to zero
RPM and speeds back up to 1000 RPM in reverse. If the noise occurs, the motor has failed
and the gearbox must be replaced (Section 9, Mechanical Service).
5.2 GEARS WILL NOT CHANGE
´ Machine will not execute a gear change.
NOTE: Whenever a gear change problem occurs, an alarm will also occur. Refer ALARMS
section (Section 6) to diagnose each problem before working on the machine.
When a gear change is performed, the following sequence of events occurs:
1) If the spindle is turning, it is commanded to stop,
2) Pause until spindle is stopped,
3) Gear change spindle speed is commanded forward,
4) Pause until spindle is at speed,
5) Command high or low gear solenoid active,
6) Pause until in new gear or reversal time,
7) Alarm and stop if max gear change time elapsed,
8) If not in new gear, reverse spindle direction,
9) Turn off high and low gear solenoids.
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Gearbox / Spindle Motor
l Check the air solenoid assembly on the solenoid bracket (rear of gearbox).
If the solenoid operates properly and the limit switches on the gearbox operate
properly, the problem lies with the gear change piston.
Replace the gearbox (Section 9, Mechanical Service).
l Check contactor CB4.
SERVICE MANUAL
SERVICE TROUBLE
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SERVICE MANUAL
Electrical
6. ELECTRICAL TROUBLE SHOOTING
6.1 WHAT CAN GO WRONG WITH LIMIT SWITCHES
If the machine is operated without connector P5, a LOW LUBE and DOOR OPEN alarm will be
generated. In addition, the Home search will not stop at the limit switch and will instead run into the
physical stops on each axis.
If the switch is damaged and permanently open, the zero search for that axis will move in the
negative direction at about 0.5 in/min until it reaches the physical travel stops at the opposite end of
travel.
If the switch is damaged and permanently closed, the zero search for that axis will move at about
10 in/min in the positive direction until it reaches the physical stops.
If the switch opens or a wire breaks after the zero search completes, an alarm is generated, the
servos are turned off, and all motion stops. The control will operate as though the zero search was
never performed. The RESET can be used to turn servos on but you can jog that axis only slowly.
6.2 SUPPLY VOLTAGE SENSOR
A sensor circuit on the SDIST circuit board is used to monitor the voltage applied to the control. It
actually monitors the DC buss voltage developed for the servo drives. When this voltage drops below
a set point, an alarm is generated. The voltage being monitored is rectified from the 115V AC secondary of transformer T1. Cable 980 carries the analog voltage from the SDIST PCB to the MOTIF PCB.
6.3 SUPPLY VOLTAGE DISPLAY
The Diagnostic Data display page is used to display this voltage. It has a range of zero to 200V
DC. If the machine is wired for 230V AC, a primary service voltage of 230V will provide a secondary
voltage of about 120V; that will produce a servo buss voltage of about 168V DC.
Note that load variations on the servo motors and spindle drive will cause slight variations in this
display. If the voltage varies by more than 10V under load, it indicates that the wiring to the control is
dropping too much voltage and may need a larger gauge wire.
6.4 LOW VOLTAGE TRIP POINT
If this voltage drops below the following limits:
205V AC when wired for nominal 230V AC service 190V AC when wired for nominal 208V AC
service
an alarm will be generated. The sensor actually converts the servo DC buss analog voltage to
digital and monitors the digital value. Both alarm trip points correspond to 140V DC on the servo buss.
If one leg of the three-phase incoming power is lost, there may not be an alarm. In this case, the
machine may turn off completely, the electronics may shut down, or the servos and the video monitor
may shut off.
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Electrical
6.5 UNDER/OVER VOLTAGE SENSORS
An overvoltage sensor monitors the DC servo motor buss. When this voltage exceeds 185V DC, a
load is applied to the servo buss. That load is called the regen load resistor. When this voltage exceeds 190V DC, an alarm is generated and machine operation stops. If the voltage remains between
these two values for more than a few seconds, an overtemperature alarm may be generated. That
alarm is caused by an overheat of the regen resistor.
The overvoltage alarm will be generated for different input service voltages depending on how the
machine is configured. The following limits apply:
260V AC when wired for nominal 230V AC service 235V AC when wired for nominal 208V AC
service
It is also possible that an overvoltage condition will be detected first by the spindle drive. This
would initially show only a spindle drive fault. A check of the status on the spindle drive LEDs will
show what the actual alarm is.
In controls built after April 1990, there is an undervoltage sensor that monitors the voltage of all
three inputs power phases. If this voltage drops below 180V AC for 208 input or drops below 200 for
230 input for any phase, an alarm will be generated. This phase sensor is built into the IOPCB circuit
board in the lower left hand corner of the control.
SERVICE MANUAL
SERVICE TROUBLE
6.6 CORRECTING ALARMS
´ Alarm 179 (Low Pressure Spindle Coolant) has been triggered.
l Check for low oil supply in reservoir.
l Check to see that pump motor is running.
l Check for an air leak in the suction side of the pump.
l Check for a bad pressure sensor.
l Check for a broken or damaged cable.
l Check for a worn pump head.
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VMC
SERVICE TROUBLE
SERVICE MANUAL
Alarms
ALARMS
Any time an alarm is present, the lower right hand corner will have a blinking ALARM. Push the
ALARM display key to view the current alarm. All alarms are displayed with a reference number and a
complete description. If the RESET key is pressed, one alarm will be removed from the list of alarms.
If there are more than 18 alarms, only the last 18 will be displayed and the CURSOR DOWN key must
be used to see the rest. The presence of any alarm will prevent the operator from starting a program.
Note that the tool changer alarms can be easily corrected by first correcting any mechanical problem, pressing RESET until the alarms are clear, selecting ZERO RET mode, and selecting AUTO ALL
AXES. Some messages are displayed while editing to tell the operator what is wrong, but these are not
alarms.
The following list shows the alarm number and the cause of the alarm. Please refer to this list
before resuming normal operation when an alarm occurs.
102 SERVOS OFF
This is not an alarm; but indicates that the servo motors are off, the tool changer is disabled, the
coolant pump is off, and the spindle motor is stopped. Caused by EMERGENCY STOP, motor f
faults, tool changer problems, or power fail.; check for other causes.
103 X FOLLOWING ERROR TOO LARGE
104 Y FOLLOWING ERROR TOO LARGE
105 Z FOLLOWING ERROR TOO LARGE
106 A FOLLOWING ERROR TOO LARGE
These alarms can be caused by power problems, motor problems, driver problems, the slide
being run into the mechanical stops, or excessive axis load. The difference between the motor
position and the commanded position has exceeded a parameter. The motor may also be
stalled, disconnected, or the driver failed. The servos will be turned off and a RESET must be
done to restart. See Section 2, Electrical Service, to check line voltage adjustments. See
Section 3.1, Electrical Service, check the servo motors, servo drivers, and ball screw adjust
ment.
107 EMERGENCY OFF
EMERGENCY STOP button was pressed. Servos are also turned off. After the E-STOP is
released, the RESET button must be pressed at least twice to correct this; once to clear the ESTOP alarm and once to clear the Servo Off alarm. This is an operator-initiated condition. If you
do not know why it occurred, check wiring to emergency stop circuit.
108 X SERVO OVERLOAD
109 Y SERVO OVERLOAD
110 Z SERVO OVERLOAD
111 A SERVO OVERLOAD
Excessive load on X-axis motor. This can occur if the load on the motor over a period of several
seconds or even minutes is large enough to exceed the continuous rating of the motor. The
servos will be turned off when this occurs. This can be caused by running into the mechanical stops but not much past them. It can also be caused by anything that causes a very high load
on the motors. See Section 3.1, Electrical Service, to check the servo motors, servo drivers, and ball
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Alarms
screw adjustment.
112 NO INTERRUPT
This alarm can be caused by electrical interference or an electronics problem. See
Section 4.1, Electrical Service, to replace Microprocessor and Motor Interface PCBs.
113 SHUTTLE IN FAULT
114 SHUTTLE OUT FAULT
Tool changer not completely to right or left. During a tool changer operation the tool in/out
shuttle failed to get to the in or out position. Parameters 62 and 63 can adjust the time-out
times. This alarm can be caused by anything that jams the motion of the slide or by the
presence of a tool in the pocket facing the spindle. A loss of power to the tool changer can
also cause this, so check fuse FU5 and relays 1-8, 2-1, and 2-2. See Section 4 for troubleshooting of the tool changer.
115 TURRET ROTATE FAULT
Tool carousel motor not in position. During a tool changer operation the tool turret failed to
start moving or failed to stop at the right position. Parameters 60 and 61 can adjust the timeout times. This alarm can be caused by anything that jams the rotation of the turret. A loss of
power to the tool changer can also cause this, so check fuse FU5 and relays 1-8, 2-3, and 2-
4. See Section 4 for troubleshooting of the tool changer.
VMC
SERVICE MANUAL
SERVICE TROUBLE
116 SPINDLE ORIENTATION FAULT
Spindle did not orient correctly. During a spindle orientation function, the spindle is rotated
until the lock pin drops in; but the lock pin never dropped. Parameters 66, 70, 73, and 74 can
adjust the time-out times. This can be caused by a trip of circuit breaker CB4, a lack of air
pressure, or too much friction with the orientation pin. See Section 4.5 to troubleshoot spindle
orientation.
117 SPINDLE HIGH GEAR FAULT
118 SPINDLE LOW GEAR FAULT
Gearbox did not shift into high or low gear. During a gear change, the spindle is rotated
slowly while air pressure is used to move the gears but the high/low gear sensor was not
detected in time. Parameters 67, 70 and 75 can adjust the time-out times. Check the air
pressure, the solenoids circuit breaker CB4, and the spindle drive. See Section 5 for troubleshooting of gear change problems.
119 OVER VOLTAGE
Incoming line voltage is above maximum (about 255V when wired for 240 or 235 when
wired for 208). The servos will be turned off and the spindle, tool changer, and coolant pump
will stop. If this condition remains for 4.5 minutes, an automatic shutdown will begin. This can
also be caused by an electronic problem. See Section 2, Electrical Service, to check line
voltage adjustment taps. See Section 4.2, Electrical Service, to replace SDIST PCB. Also
check that servo regen load resistor is installed (cable 920).
120 LOW AIR PRESSURE
Air pressure dropped below 80 PSI for a period defined by Parameter 76. Check your
incoming air pressure for at least 100 PSI and ensure the regulator is set at 85 PSI. If this is
not caused by low air pressure, check pressure sensor at spindle head and wiring back to
IOPCB. Check Parameter 76, which is used to delay the low air alarm condition for short
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