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Service Knowledge Base
CNC machines BARUFFALDI turrets
Backlash measuring and setting TOE turret not fixed
Turret alignments (body and disk) Check and align the encoder
Over travel alarm before home position Turret will not stop
Chuck is not working Coolant gasket installation for TOE turret
2004 AC alarm How the TOE turret works?
Diagnostic: check the inputs and outputs Replace the TOE side shock absorbers
Replace the linear bearings on the SL-320 Download the TOE service drawings
SL-500 hydraulic tailstock operation/switches  
FANUC spindle drive fuse location  
Installation procedure for the SLT lathes  
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CNC service questions? Visit this site


Backlash measuring and setting
Put a dial indicator to the tool holder or the turret disc in X direction from the chuck or the tailstock body. Move the slide by the JOG, in the + X direction until the dial moves. Move the slide in the -X direction 3 times, and read the last movement of the dial. The difference of the movements is the backlash. If you pushed the + X more than once, add 0.0010 each times to the difference.

Example: you pushed the +X two times, the dial moved only 0.0004. In this case the backlash would be = 0.0010 + 0.0008 = 0.0018(in X direction all values are in diameter). Convert the backlash value to metric: 0.0018*25.4=0.0457 =46 micron. Add this value to the value of the # 535 parameter (should the change be more than 25-35 %, call the service.). The checking and the setting of the Z backlash is the same as above: move the slide first in - Z , and than + Z direction. The Z backlash value is in the parameter # 536.

Read an article about "Checking Backlash On Lathes" By Michael W. Breen

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Turret alignments (body and disc)
Check the perpendicularity of the turret face to the center line of the main spindle. Place the dial indicator to the face of the chuck and measure the face of the turret while the X-axis is moving in either the + and - direction. The face could be tilted back to the maximum amount of 0.001/6" on the top. Check the center line of the tool holder pocket to the center line of main spindle. Place the dial indicator to the chuck and move the turret to the center in X-direction by swinging the base with the chuck . The dial tester should be in the ID tool holder hole. The center can be higher by 0.001-.003" in the A direction

Adjusting the tilting of the turret

Loosen the bolts that are fixed to the turret body (the turret tilts around the bushing which is between the turret body and the sub-plate at the 2nd bolt on the top). 2. Adjust the tilt by checking the face of the disc. In case of a big collision, make sure that the plate between the turret and the cross slide did not move. If it happened, simply take off the turret, adjust the plate, and replace the taper pins. After the plate is secured, put the turret back, align it, and tighten the bolts securely.

Adjusting the height of the tool holder centerline of turret disc

Pull out the taper pin. Normally, a pin puller is required for this task. (However, not every turret disk has a taper pin, because at normal cutting conditions, the front bolts hold the disk securely.) 2. Loosen the bolts at the face of the disc 3. Adjust the turret disc by watching the swing of the dial indicator, while the dial tester is inside the hole of the ID tool holder (a rubber hammer will suffice to adjust the disc). 4. Tighten the bolts securely. 5. Insert the new taper pin. (10mm at small end, 45 mm long). In case of a big collision, make sure the hole is reamed for the taper pin.

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Over travel alarm before home position
If you couldn't reach the home position, because you OVER TRAVEL alarm, do the followings:

1. Turn off the CNC control.

2. Push and hold down the P and the CAN button together, while the POWER ON will be pushed. When the control and the machine is ON, released the buttons.

3. Move the slide manualy to the HOME position.

(This is happening, when the ball screw was rotated by hand, and the synchrony was broken between the absolute position of the slide and the encoder)

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Problems with the chuck?
1st: Is the hydraulic unit not working? Push POWER ON again and the hydraulic unit should start.

2nd: Is there no hydraulic pressure? Check the dial again, set the pressure higher, and the chuck should start to work.

3rd: Is the foot switch working? Check the input signal of the foot switch on the diagnostic screen (X-input), see Service KB C6 how to check the diagnostics. If the input is not OK, check the switch inside for contacts. The wire could be broke, the wire terminal could be corroded. Check the foot pedal, can you press it all the way down? - or there is a chip under it? If the input is OK, check the output to the solenoid. If the output is not made after the foot switch operation, an internal switch from the ladder program will show the broken line.

4th: Is the chuck working by the MDI M-code command? If the chuck is working with M-code, but not with the foot switch, check the switch.

5th: Is the output of the solenoid OK? If yes, it could be a broken wire at the connector of the solenoid, the connector could be loose, or the wire of the coil could be broken. Switch the two connectors of the solenoid to check the other side of the solenoid.

6th: Is the draw tube, which connects the hydraulic cylinder and the chuck, not working? The tube could be unscrewed from the cylinder or the chuck. Also check the chuck body, especially the internal wedge, which should be greased up on a regular schedule. If the chuck is dirty or not greased inside, then the draw tube can't operate the chuck in a full extend.

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2004 AC alarm
There are AC motors for several units: the chip conveyor, slide lubrication, hydraulic unit and the turret.

If one of the motors is overloaded and the overload relay (the circuit breaker) is turned off, an AC alarm will be generated.

When you open the electrical cabinet, you can find the relay turned off. You'll notice a sign near the relay unit (ex. 6CB12). The first number of the sign will indicate the group number of the unit – like hydraulic for example.

Check the motor of the indicated unit. If it is a chip conveyor motor, the problems are usually related to long chips, which are stuck somewhere, possibly due to the coolant pump, which could have sucked in some chips or dirt.

To restart the motor, wait until the motor cools down, and then turn the overload relay back on.

To clear the alarm, simply push reset.

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Diagnostic: check the inputs and outputs
SELF-DIAGNOSTIC search and check

The bits of the diagnostic numbers indicate the status of the machine,

- input signals: from the machine to the CNC control and (X…)

- output signals: from the CNC control to the machine (Y…)

1. Display the diagnostic data , numbers and the bits

DGNOS/PARAM à DGNOS soft key à

DGN number Bit No.
  7 6 5 4 3 2 1 0
X 0000 0 1 1 0 1 0 1 0
X 0001 0 1 0 0 1 1 0 0
X 0002 1 1 0 0 1 1 0 1
Y 0048 1 0 1 0 1 0 0 1
Y 0049 1 1 0 0 1 1 0 1
Y 0050 1 1 0 0 0 1 0 1

The diagnostic screen has more than 1 page, change the page by the following way: 1 - PG UP and PG DOWN or 2 - Press the No. key - Key in the diagnostic number to be displayed - Press INPUT key

2. Input signals
Example: DIAGN #2 X002.2 = Tailstock quill in front position (Bit #2 is the 3rd from right ) 1=ON - quill is in front position

3. Output signal
Example: DIAG #50 Y050.3 = Tailstock quill retracted (Bit #3 is the 4th from right) 0=OFF-NO QUILL MOVE COMMAND FROM THE CNC

4. Checking out the execution of the CNC commands

Example: tailstock quill retract, MDI command - M54

MDI à PRGRM à M54 à INPUT (the M54 has been inputted and displayed)à

DGNOS/PARAM à DGNOS à NO. (numeric keypad) 50 à INPUT (the cursor is jumping to DIAGN No.50)


When the command is executed, the bit #3 is changed to 1 and the quill will move backwards. When the quill reaches the back position, the bit #3 is changed to 0, which indicates that this output is not ON anymore.
In the same time, the input bit of the switch of the back position will be changed to 1, showing the ON signal of the switch. Input bit: X002.3 (DIAGN #2, bit #3)

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Linear bearings at the SL-320

LB - linear bearing

TG - taper gib

KG - keeper gib

SC - screw for the taper gib

The slide system has 4 linear bearing on each side. The two linear bearing are bolted to the back side of the keeper gib. This keeper gibes are bolted to the back side of the Z-slide.

The linear bearing on the top of the way is bolted (M3) to a distance plate, which is fitted between the slide and the way. The keeper gib has two pin, which holds the bearings in place. You need to take off the keeper gib first, and lifted up the slide about 0.05" (jack screw or pray bar) in order to pull out the bearing with the distance plate.

The linear bearing on the bottom of the way is bolted to a taper gib (TG), which can be adjusted by the screw (SC). In order to set the taper gib, check the backlash and the tilting of the Z-slide. If the CNC control has a current % indicator of the Z-motor, check the value, which would increased rapidly, when the taper gib is too tight.

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FANUC spindle drive fuse location
Location of the fuse of the spindle drive. Fuse specification: 50V F5.0 DAITO

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Turret not fixed
The turret locking proximity switch will send the signal, when the turret has been locked, when the roller carrier is in the middle position, and the locking crown (short - circuiting ring gear) is in the front position. 1st. : check the signal output at the terminal. If there isn't any, check the proximity switch, by pulling it out and holding a metal object in front of it. If the switch is good, check the gap between the end of the switch and the high spot oft the roller carrier. The gap should be about 0.8mm (0.030"). Check, if the turret rotation will be stopped by the pre-indexing pin? (see Service KB T3)

If it has been stopped, check if the motor has been reversed, in order to lock the turret? If the motor reversed and the locking signal is coming only for a short time, very likely the inside shock absorber pads are worn out, ask advice from our service, how to change them, or send the turret to the service center for repair.

If the locking signal made only for a short time, the motor could not have been stopped by the brake, check and set the right air gap.

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Checking and setting the encoder
If you have to change the turret encoder, it is very important to set the position of the encoder. Make sure the turret is locked in any position. Rotate the new encoder until the turret disk position and the encoder position bits are matched (you can check this on the diagnostic screen of the control, or measure the position bit signals at the wire terminal).

At that point, rotate the encoder slowly in one direction, until the strobe signal will be low and make a mark on the encoder bracket. Rotate the encoder in the opposite direction until the strobe signal will be low again and make the 2nd mark. Rotate the encoder back between the two marks, and secure the screws.

The strobe signal needs to be on in order to energize the solenoid of the pre-indexing pin.

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If the turret will not stop
The turret indexing motion is stopped by the pre-indexing pin, which is pushed down by the pre-indexing solenoid. The solenoid is energized by the strobe signal (by means of a relay) of the encoder . (see : how to set the encoder ). 1st: Make sure that a strobe signal is coming from the encoder. Check the relay of the pre-index solenoid. 2nd: Check the pre-index solenoid with 24VDC (which you can get it from the brake circuit). If the pin of the solenoid is not moving freely, use some lubricant (WD40).

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Installation of the coolant gasket for the TOE series turrets
  1. Clean the surfaces of both the disc and the turret.
  2. Remove the protective paper from the back of the gasket.
  3. Place the gasket firmly into the mold of the coolant distributor ring and press it down evenly.
  4. Apply silicon to the inside corners of the gasket (make a 45 degree slope) and let it dry.
  5. Apply a thin layer of grease to the back face of the turret disk (this will enable the disk will slide better during the alignment).
  6. Install the disc in place and insert and tighten the bolts until the disk is touching the face of the turret.
  7. Align the disk and tighten the bolts.

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How the TOE turret works?
  • Brake 175 connected
  • Motor disconnected
  • Electromagnet 200 disconnected
  • Rotating crown 003 linked to the fixed crown 002 through the short circuiting crown 004.

The disc springs (Belleville) are pressed, by means of the three rollers on the three cam ends of the short circuiting crown, keeping the Hirth teeth of the crown in contact.


Electricity is cut off from the brake and connected to the motor which, through reduction gears starts rotating the planetary roller ring 006, which stops, after a preset angle, against a positive stop.
During this phase the central spring 034 pushes the short circuiting crown (004) back, because the roller descend on the cam and this movement unlocks the rotating crown(003).That will result to rotate the main shaft of the turret by means the pinion .
Nearing the target tool station, the strobe signal (given by angular encoder 160),energise the electromagnet 200 and the magnet pushes down the pre-indexing pin 017 into the pre-positioning recess in the divider 005.This will stop the rotation of the crown and the tool holder disk which is bolted to it. The resulting shock is absorbed by the buffer pads 032.
While the electromagnet moved down, the pre-indexing proximity switch 301sent a signal.
Arrival of this signal causes the reverse of the motor rotation, and also the planetary roller ring 006; so that the rollers rise on their cam ends and push the short circuiting crown ahead, causing the Hirth teeth to engage.
Passage of the external profile (I) of the planetary roller ring 006, activates the locking proximity switch 313, indicating that the turret is closed.
When this signal arrives, current will cut off from the motor and the brake 175 will be energized to keep the motor in this position. Immediately afterwards the electromagnet is deactivated, and consequently the pre-indexing pin pushes out of the recess by the spring 047.

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Replace the TOE side shock absorbers

Unscrew the side cover, the shock absorber is behind the cover. Watch for the small O-ring on the cover. Tighten the cover back, until the surface is flash with the turret body.

The older TOE turret has 3 bolts for the cover.

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