Bernardo URS 3000 N Universal Cylindrical Grinding Machine
Bernardo URS 3000 N Universal Cylindrical Grinding Machine is backordered and will ship as soon as it is back in stock.
Subscribe to our newsletter
Get the latest updates on all our new collections, sales, offers and product arrival dates.
-
Description
-
Product safety
-
Reviews
Description
The Bernardo URS 3000 N universal cylindrical grinding machine grinds externally from Ø 8 to 320 mm and internally from Ø 35 mm, on workpieces up to 3000 mm between centers and with a maximum weight of 150 kg, featuring a hydrodynamic spindle, inclinable table, external grinding wheel Ø 500 × 50 × 203, and an internal grinding speed of 10,000 rpm. Produced in Austria, distributed in Italy by Krollit as an official Bernardo distributor since 2007.
- Distance between centers: 3000 mm
- External grinding diameter: 8–320 mm
- Internal grinding diameter: 35–100 mm
- Maximum workpiece weight: 150 kg
- Workpiece spindle speed: 25–220 rpm
- External grinding wheel: Ø 500 × 50 × 203 mm
- Internal grinding speed: 10,000 rpm
Who uses the URS 3000 N and for what
The Bernardo URS 3000 N is a professional universal cylindrical grinding machine for precision external and internal grinding of shafts, pins, bushings, and seats: the machine that achieves surface roughness below Ra 0.4 µm and dimensional tolerance in the order of hundredths of a millimeter on workpieces up to 3000 mm in length. The hydrodynamic workpiece spindle — the main differentiator compared to grinding machines with rolling bearings — ensures constant precision even over prolonged cycles, as it eliminates vibrations transmitted by the bearings. The grinding head, inclinable by ±30°, allows grinding of tapers, spherical seats, and shoulders. In Krollit customers' workshops, it is used by precision mechanical workshops, equipment manufacturers, and industrial maintenance centers that work with high-precision components.
Who is the Bernardo URS 3000 N for
| Profile | Compatibility | Reason |
|---|---|---|
| Hobbyist | Not suitable | Industrial precision grinding machine. Not suitable for hobby use. |
| Precision mechanical workshop | Ideal | External and internal grinding on workpieces up to 3000 mm with hydrodynamic spindle: the choice for tolerances in the order of hundredths on shafts and bushings. |
| Industrial production | Ideal | For maintenance and production of precision components in continuous cycles. |
Not suitable for: workpieces over 3000 mm in length (consider a larger model); workshops without knowledge of cylindrical grinding; occasional use where a bench grinder is sufficient.
Working capacity
| Specification | Value |
|---|---|
| Distance between centers | 3000 mm |
| Center height | 180 mm |
| External grinding diameter | 8–320 mm |
| Maximum workpiece weight | 150 kg |
| Internal grinding diameter with steady rest | 35–100 mm |
| Internal grinding diameter without steady rest | 30–100 mm |
| Max. internal grinding depth | 125 mm |
Table and feeds
| Specification | Value |
|---|---|
| Table inclination | +3° to −2° |
| Table longitudinal travel | 3100 mm |
| Table feed | 0.1–3 m/min |
| Manual table feed | 6 mm/rev |
Workpiece spindle and grinding wheel
| Specification | Value |
|---|---|
| Workpiece spindle speed | 25–220 rpm |
| Workpiece spindle taper | MT 4 |
| Spindle inclination | +90° |
| External grinding wheel (Ø × W × bore) | Ø 500 × 50 × 203 mm |
| External grinding wheel speed | 1330 rpm |
| Internal grinding speed | 10,000 rpm |
| Grinding head inclination | ±30° |
Compliance and safety
| Specification | Value |
|---|---|
| Marking | CE |
| Directive | Machinery 2006/42/EC |
Logistics
Bernardo shipping: 5–9 working days (7 days to the South). Heavy precision machine: coordinate unloading equipment with Krollit before delivery. Original spare parts available with 3–5 working days shipping. Customer support in Italian available.
Frequently Asked Questions
What does "hydrodynamic spindle" mean and why is it important?
A hydrodynamic spindle supports the shaft on an oil film instead of rolling bearings. This eliminates the micro-vibrations typical of bearings — which transfer to the ground surface as undulations — and ensures superior dimensional repeatability. It is the standard for industrial precision grinding machines. Grinding machines with rolling bearings cost less but do not achieve the same tolerances.
What dimensional accuracy can be achieved with the URS 3000 N?
Under optimal conditions (well-balanced workpiece, correct grinding wheel, adequate coolant), the URS 3000 N achieves dimensional tolerances of IT5–IT6 (in the order of hundredths of a millimeter) and surface roughness Ra 0.2–0.4 µm. Actual precision depends on the operator, material type, and operating conditions.
What type of grinding wheel is used for internal grinding?
For internal grinding, the head reaches 10,000 rpm — necessary to maintain optimal peripheral speed with small diameter grinding wheels. Cylindrical grinding wheels mounted on a spindle with a diameter compatible with the bore to be ground are used. For different materials (steel, cast iron, aluminum, carbides), grinding wheels of different compositions (corundum, silicon carbide, CBN) are used.
Is 45° grinding and tapering possible on the URS 3000 N?
Yes. The grinding head can be tilted by ±30° relative to the workpiece axis, allowing for grinding of tapers, angled shoulders, and complex shapes. The table can be tilted from +3° to −2° for grinding tapers on long workpieces. The combination of the two inclinations covers almost all geometries required in a precision workshop.
What coolant is used?
For cylindrical grinding, a 3–5% water+oil emulsion or neat grinding oil is typically used, depending on the material and grinding wheel. The URS 3000 N's cooling system is integrated. Contact Krollit for details on the coolant delivery system.
