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FAQ

FACE DRIVERS

1. How do you replace the driving pins in a face driver ?

To replace the driving pins of a face driver there is no need of any tools or wrenches, just hand the driving pin and make it slide axially to extract it. To insert the driving pins again, make them slide in direction of the face driver’s axis, keeping the milled plane turned outwards. This operation can be made with the face driver assembled on the machine without compromising its accuracy. During this operation, we suggest to regrease the driving pins in order to create a thin film.
Instructions for a correct maintenance.

2. How often have the driving pins to be sharpened in a face driver ?

The wear of the driving pins in a face driver is difficult to quantify in working hours or in machined parts because of the different materials to be machined and different working parameters, but:
– For those who often changes typology of machining has to sharpen the driving pins when their edges are chipped or have a little plane on the cutting points and when on the part machined the four marks made by the face driver are not straight but slightly open (fan-shaped). In these conditions, a sharpening of just a few tenths of millimeter will be necessary.
– For those who has big ranges of parts to be machined, will provide to sharpen the driving pins constantly after a certain number of machined parts.

3. How many millimeters can the edge of a driving pin be reduced of ?

Driving pins can be sharpened reducing the blade of 3 mm max. Do not shorten the driving pins for more than 3 mm in order to grant a regular stroke of the center point. Make sure the blade isn’t warmed up during sharpening operation.

4. How do you replace a center point in a face driver ?

FACE DRIVERS WITH CENTER POINT OPERATED BY SPRINGS: to replace the center point in a face driver with center point operated by springs, no tools or wrenches are needed, just hand the center point and make it axially slide to extract it. If necessary, use a rag or pliers to better grip it. To reintroduce the center, make it slide in direction of the face driver’s axis to its support. The above operation can be made with the face driver assembled on the machine without compromising its accuracy.
Instructions for a correct maintenance.
FACE DRIVERS WITH FIXED CENTER POINT: in the face drivers with fixed center point there are one or two dowels (it depends on type) that keep the center point locked in its slot. Before changing the center point, unloose the locking dowels and, once replaced the center point, loose again the dowels being careful to lock again the milled parts overall the center point.
Instructions for a correct maintenance.

5. How often has a face driver to be serviced ?

Servicing is not so frequent for the face driver because of its completely mechanical system. However, every about 400 working hours, we suggest removing the driving pins and the center point to regrease them in order to create a thin film that avoids introductions of coolant into the body of the face driver. However, when you stop keeping tolerances required during machining, we suggest to send the face driver back to our factory to be serviced.
Instructions for a correct maintenance.

6. What is the function of the radial dowels in the face plate ?

There are 4 radial dowels on the face plate of the face driver are necessary to limit driving pin rotation. Their positioning has to allow a rotation of the driving pins around their own axis of 2÷3 tenths of millimeter. These dowels are set by the factory when fitted and NO FURTHER ADJUSTMENT IS REQUIRED.
Instructions for a correct maintenance.

7. What is the function of the back screw in the face drivers ?

The back screw placed in the face drivers (versions with center point operated by springs), has the function to keep preloaded the belleville spring washers located inside the body. The adjustment is made by the factory during assembling and NO FURTHER ADJUSTMENT IS REQUIRED.
Instructions for a correct maintenance.

8. How do you determine the rotation direction of the face driver ?

On the face driver, driving pins with clockwise rotation or counterclockwise rotation can be assembled. To determine the direction of rotation, look in front of the face driver: the most inclined side of the blades is the driving one, so the side that has to drag. Example: right inclined side-clockwise rotation, left inclined side-counterclockwise rotation. Once the face driver is fitted in the machine, verify the spindle rotation corresponds to the rotation of the driving pins assembled on the face driver.
How the “wedge lever” system works.

9. Is it possible to machine parts with a hole instead of a center ?…Use center points with slots.

With the face drivers, also parts with a hole with large or small diameters instead of a center, can be machined by fitting a center point with slots of the right dimension. When using the center points with slots, always check overall driving pin lenght: this must never be less than 3 mm. of the original lenght indicated in the catalogue. It means that, when sharpening, drivin pins can be shortened down to 3 mm. of their original overall lenght.means . To ensure that the point with slots operates efficiently, care must be taken to ensure that it never comes into contact with the level of the driving pin face plate.
Clamping face drivers with integral flange.

10. How do you clamp a face driver on a self-centering chuck ?

To correctly clamp the face driver in a self-centering chuck, it is necessary to turn the soft jaws in order to take up the axial and radial slack of the self-centering chuck. Machine the diameter “D” after clamping a round flange of suitable diameter in the three jaws. Then, machine the diameter “C” after clamping the appropriate ring in the diameter “D”.
Using the center points with slots.

LIVE CENTERS

1. During machining, can the live center get hot?

Yes, it is normal the live center gets hot because of the radial roller bearings  fitted in the live center that,especially when the live center is used at the maximum rotational speed specified in the reference table, also temperatures beyond 40° are normal.

2. Is a leakage of grease from the live center normal?

Yes, this leackage is due to the discharge of the surplus grease from the live center during its first working hours. All live centers, except for “65″ series, are filled with special long life grease. When the live center is new, or after a periodical overhaule, a slight leakage of grease from the front is normal.. If leackage of grease goes on also after 2-3 working days, call technical assistance. Probably there could be any seal damaged. No topping up of grease is needed.

3. Is a periodic filling up of the oil necessary in the live center?

The live centers “65″ series, are filled with oil that serves as a lubricant. The oil inside is a dispersal oil so it is necessary a periodical topping up of the level every 80-100 working hours in this way: unscrew the screw placed in the body and pump the oil, filling the live center, and stop when the oil comes out from the front part of the live center.

4. How often does the live center need servicing ?

The live centers “65″ series need periodical servicing every 80-100 working hours by topping up the oil level.
Every about 900 working hours, the live centers “65-80″ series need to be adjusted by means of the adjusting ring, in order to take up any possible slack of the tapered roller bearings.   Click here for further details.
The live centers “85″ series for turning, “82″ series for gear cutting and “RAPIDO” series don’t need above operation. The live centers for grinding need a periodical servicing every 150 working hours by taking off the water guard cap and replacing the inside grease MOLIKOTE.
For more important repairs (replacing of bearings, seals, and so on) there is not a definite life because it depends on the kind of use made by the user. However, we suggest to send us the live center for repairing as soon as you note a loss of accuracy or noise of rolling of the bearings, avoiding a complete stop of the live center.

5. What is necessary to do after a long stop before restarting machining?

After a long stop of a live center, some simple operations have to be done:
- for the live centers “65″ series, top up the oil until it comes out of the front.
- for the live centers “80″ and “85″ series, proceed at a low speed for some minutes. By means of this operation the grease placed inside will be remixed to obtain a correct lubrication again.

6. How many r.p.m. are permitted when using a live center ?

– For working speed of live centers ″65 series″. click here.
– For working speed of live centers ″80 series″. click here.
– For working speed of live centers ″85 series″. click here.

7. What kind of center can be fitted on a center carrying dead center ?

The centers that can be fitted on the center carrying dead centers with extraction thread for turning shafts and pipes MT3, MT4 and MT5, are those ones with the connection for the live center MT5.
Click here for further details.

8. How do you replace an interchangeable center ?

To replace an interchangeable center on a live center or on a center carrying dead center, take a spanner of the right size and, after clamping the center in a vice, fit the spanner around the live center shaft and rotate firmly as when tightening a screw.

Once taken off the center, it will be necessary to clean both the seats and connect the cones by exerting pressure. It is advisable to remove the center from the live center if the live center will not be working for a long period.
Useful advices for a correct use and maintenance.

9. How do you replace a head in a head carrying live or dead center ?

To replace a head fitted in a live center for pipes tighten a screw inside the thread placed on the top of the head till the screw rests on the shaft; then pull with a spanner to extract the head and, for replacing, clean the seats and put the head on the shank of the center and press to connect the parts.

10. What is the function of the support nut in the live centers ?

The support nut is fitted in the body of the live centers MT2, MT3, and MT4 for a better stiffness and in order to check any deflections or vibrations caused by duty tasks of the live center.
Useful advices for a correct use and maintenance.

11. What is the function of the extraction nut in the live centers ?

The extraction nut in the live centers can be fitted in all morse taper sizes and has 2 functions: better stiffness and to extract the live center from its seat by means of a pin wrench.
Useful advices for a correct use and maintenance.

12. How do you adjust the live center ?

This operation is made in case of a possible slack of the tapered roller bearing of the live center with consequent loss of accuracy of the live center. The adjusting is made only for the live centers for turning “65″ and “80″ series.
Useful advices for a correct use and maintenance.
To adjust the live center, use the following procedure:
- Bloccare la contropunta in morsa.
- Clamp the live center in a vice.
- Loosen the adjusting nut screw placed in the body of the live center.
- Take out by means of a screw driver, the chip guard ring placed on the adjustment ring.
- Mark with a felt tip a sign of reference on the adjustment ring and on the body of the live center.
- Use a torque wrench to tighten the adjustment ring and move the sign of few millimeters.

To correctly adjust the live center, remind that the live center, when not subjected to axial load, does not travel smoothly; this is due to the counter pressure of the spring which distributes the axial load between the two thrust bearings. Live centers for turning “85″ series, those ones “82 series” for gear cutting, those ones for grinding and “RAPIDO” series do not need adjustment.
Useful advices for a correct use and maintenance.

13. What is the axial load the live center can carry ?

– For axial loads of live centers “65 series″. click here.
– For axial loads of live centers “80 series″. click here.
– For axial loads of live centers “85 series″. click here.

14. What is the radial load the live center can carry ?

– For radial loads of live centers “65 series″.  click here.
– For radial loads of live centers “80 series″. click here.
– For radial loads of live centers “85 series″.  click here.

15. How do you replace the shaft in a live center for hobbing ?

To replace the shaft in a live center for gear cutting use the following procedure:
– Unscrew the front water guard cap and take it off.
– Clamp the protruding part of the shaft in a vice.
– Unscrew the rear screw which keeps the shaft locked in its seat.
– Keeping clamped the shaft in the vice, take the body of the live center out of the shaft by hand. – Insert the shaft to be replaced.
– Press it in order to put it again in its final seat.
– Drive the rear screw in its lock washer to lock the shaft.
– Insert again the cap by screwing it in its seat.