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MACHINE TOOL |
C.B.Ferrari began to build high speed machines in 1989 with serie "A" and "B" milling machines. These machines are equipped with linear rollers guides and a Numerical Control composed by two 286+287 class Personal Computers capable of reading up to 200 program lines per second.
In 1996 the axes drivers became digital and interfaced with the CNC using an optical fiber link.
The mechanical design has been revised to reduce the moving masses, to take the best advantage from the high moving speed, keeping however the structure rigid and strong.
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In this way the machine is able to mill not only tempered metarials where a small amount of metal is removed, but also steels and alluminium because the structure is suitable also for working where a big amount of metal is removed (rough). The guides are made with linear rollers bearings to get volvent friction (instead of recirculating skates). These guides, correctly preloaded, distribute the forces on the whole lenght and give to the structure high rigidity. |
MACHINE AXES |
With many years of experience in using digital motors and optical links between CNC and axes drivers we can say that the traditional working parameters have been revolutioned.
With these kind of systems, it is possible to anticipate the motor response, knowing speed and acceleration (it is no more necessary to wait the CNC answer to correct the position as in the case of analogic axes drivers and Brushless motors).
This mean movements 5 or 6 time faster and increased precision.
DIGITAL NUMERICAL CONTROL |
The latest Elexa's NC, E580, is based CompactPCl platform, an acknowledged international standard suitable for industrial application where the environment requires ruggedness, noise immunity and dirt-proof. Elexa's E580 is equipped with two PC-like boards connected through parallel interface for high throughput.
The machine's dynamic is regulated along a trajectory by employing continuous curves, guaranteeing that axis kinematics is always monitored to avoid undesirable oscillations or vibrations. A "look-ahead" function allows the control system to compute on-line the most suitable speed value according to the profile properties. Feed-forward techniques can be employed for keeping dynamic following errors close to zero.
The NC, equipped with the WinNT operating system, can run several applications simultaneously, satisfying all the requirements CAD/CAM systems or factory integration with no overhead for the control unit. A simple and intuitive interface allows the end-user to learn in a very short time how to operate the E580 NC A fully integrated CAM system, enables the standardization of the programming tools between the workshop and the office.
2 CPU Digital Control
- Up to 16 digital axes, including digital spindle.
- Measurement system for absolute scale and or absolute inductosyn.
- Acceleration automatic tuning for heavy loads on the table.
- Look-ahead capabilities.
- Measurement system and thermal compensation available on all axes.
- Automatic positioning for axes and spindle.
- Feed up to 150 mt/min.
- 2 hand-wheel, selectable for any axis.
- High speed cutting capabilities: acceleration and jerk control along the tool path.
Programming
- Programmable tool radius either in program or in tool table.
- 3D matrix computation for rotated and translated coordinate systems.
- 50 origin positions.
- Mirroring and scaling on all axes.
- Pre-programmed cycles, macro programmable by the end-user.
- 5-axes NURBS interpolator.
- G63 modal function for high speed cutting.
- Block computation time for 3 axis 0,12 ms.
Tool Handling
- Life and wear monitoring.
- Presetting cycles for length and diameter.
- Profile grinding cycle.
Diagnostic
- Clear messages for PLC functions and programming. Remote monitoring capabilities.
Serial Data Links
- Ethernet 100 Mbps (on cable)
- Sercos (on optical fiber).
- Profibus-DP (on cable)
- Can Bus (on cable)
- RS 232 (on cable)
- USB (on cable).
Video
- 15" STFT
ELECTROSPINDLE |
C.B.Ferrari design and produce theirs own electrospindles since 1992.
Electrospindle range :
24/35 kW |
16.000 RPM |
ISO V45 |
190/270 Nm |
24/35 kW |
16.000 RPM |
ISO V40 |
90/130 Nm |
24/35 kW |
16.000 RPM |
HSK-A63 |
90/130 Nm |
| 24/35 kW | 20.000 RPM | ISO V40 | 68/96 Nm |
| 24/35 kW | 20.000 RPM | HSK-A63 | 68/96 Nm |
12/17 kW |
22.000 RPM |
ISO V40 |
20/28 Nm |
12/17 kw |
30.000 RPM |
ISO V40 |
20/28 Nm |
11/15 kw |
30.000 RPM |
ISO V30 |
5/7 Nm |
11/15 kw |
40.000 RPM |
ISO V30 |
5/7 Nm |
Another advantage in producing the electrospindles, is the possibility of giving to our customer a fast, reliable and low cost service.
How to select an electrospindle :
max tool Ø |
min tool Ø |
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24Kw - 16.000 RPM |
100 mm | 2.5 mm |
24kW - 20.000 RPM |
50 mm |
3 mm |
12kW - 22.000 RPM |
30 mm |
2 mm |
11kW - 30.000 RPM |
20 mm |
1 mm |
11kW - 40.000 RPM |
20 mm |
0.5 mm |
5 AXES WORKING |
C.B. Ferrari provides to its customer high technology equipments such as digital axes, electrospindles, high performances CNCs, software, rigid structures, continuous heads, rotating tables, dividing units and so on. With these equipments, the customer can take great advantages from a 5 axes milling machine.
The advantages can be summarized as follows :
with a better surface finishing and an increased tool life.
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Traditional way |
Optimized way |
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Workpiece orientation to reduce tool length |
TOOL HOLDERS |
C.B. Ferrari takes great care designing these accessories, because they are very important to get a good precision on workpieces made at high speed.
The holder is composed by two parts, each one mobile respect to the other : the body and the conical bush.
When the tool holder is mounted into the spindle, the body flange stay
s in contact with the electrospindle plane, while a group of springs keep the bush perfectly centered inside the conical coupling site.This tool holder is directly interchangeable with standard DIN holders.
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C.B.Ferrari recently has developed a new holder type (Ø from 3 to 20 mm) specifically designed for high speed milling, where the tool is locked by thermal dilatation. This locking system gives more advantages respect to the older one :
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Both aspects are fundamental for the precision on the workpiece, for a longer tool life and consequently for costs reduction.
TOOLS |
High speed milling means to remove small amount of metal with high feed rate.
The high feedrate on the workpiece requires some tricks to be applied to never compromise the tool life.
Smooth trajectories (ramp or helicoidal) have to be preferred and the tool movement on the workpiece must
be on profiles connected by small radius.REMOVING CAPACITY
ALLOY STEELS Pe = 0,05 ÷ 0,10 x Ø Pa = 0,05 ÷ 0,10 x Ø FZ = 0,005 ÷ 0,10 x Ø |
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TEMPRED STEELS Pe = 0,01 ÷ 0,02 x Ø Pa = 0,04 ÷ 0,06 x Ø FZ = 0,002 ÷ 0,005 x Ø |
EMPTYING WAYS
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On alloy steels - Pa = up to 0,04 x Ø |
On tempered steels - Pa = up to 0,01 x Ø |
CUTTING PARAMETERS COMPARATION
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Traditional way
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High speed way
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INDICATIVE CUTTING SPEED
ALLUMINIUM up to 4000 m/min
ALLOY STEELS up to 500 m/min
TEMPRED STEELS (microgranular tools) up to 400 m/min
TEMPRED STEELS (CBN tools) up to 1000 m/min
FINAL CONSIDERATIONS |
HSC disadvantages:
HSC advantages:
