Bernardo Turning Gouge Support for NTS 200 / NTS 250 Pro / NTS 250 Pro Vario
Internal turning (machining holes, grooves, internal profiles) is one of the most precise operations on centre lathes. It requires rigid and precise tool (gouge) positioning to prevent vibrations and ensure consistent finishes. The Bernardo support establishes the tool's centre of gravity relative to the rotation axis, eliminating oscillations and allowing operations at optimal speeds and feeds.
Unlike free positioning (held manually), a dedicated support allows for repetitive reliability. Professionals working with small diameters (< Ø 50 mm) or great depths (> 100 mm) will find the support essential.
When to use the support:
- Internal turning on diameters < Ø 50 mm (small holes, grooves, internal threads)
- Working depth > 100 mm (natural gouge instability)
- Repetitive finishes requiring tight tolerances (±0.1 mm)
- Hard materials (steels, grey cast irons) that amplify vibrations
Benefits compared to manual positioning: Guaranteed ±0.05 mm precision, higher spindle speeds (+40%), better surface finish, reduced vibrations, possibility to entrust operation to a young, inexperienced operator.
Who the Bernardo internal turning support is suitable for
| Profile |
Suitable? |
Reason |
| Craftsman / small workshop |
Ideal |
If internal turning accounts for 20-40% of monthly production, the support pays for itself in 100-150 hours of use. |
| Industrial maintenance / spare parts |
Ideal |
Spare parts with internal holes and threads are the norm. The support reduces scrap and rework by 30-50%. |
| Job-shop workshop |
Ideal |
Versatility on NTS 200/250 Pro allows management of different batches without long setups. Enables junior operators to achieve senior quality. |
| Small batch production |
Adequate |
If batches are > 50 identical pieces, the support speeds up the cycle and reduces scrap. If batches are < 20, the setup is not justified. |
Technical specifications
Machine compatibility
| Machine |
Compatible? |
Notes |
| NTS 200 |
Yes |
Standard mounting on tool holder |
| NTS 250 Pro |
Yes |
Standard mounting on tool holder |
| NTS 250 Pro Vario |
Yes |
Compatible, speed change not affected |
| Other Bernardo machines |
Check |
Compatible if standard tool holder |
Functional characteristics
| Parameter |
Value |
| Device type |
Rigid support for internal turning gouges |
| Application |
Turning holes, grooves, internal threads |
| Positioning accuracy |
±0.05 mm |
| Tool diameter range |
Ø 6 mm – Ø 16 mm |
| Maximum machining depth |
Up to 300 mm |
| Support body material |
Steel/cast iron, heat treated |
| Mounting |
On lathe tool holder (collet/vise) |
| Adjustment |
Manual, 3 axes X-Y-Z |
Compliance
| Parameter |
Value |
| Manufacturer |
Bernardo GmbH, Linz (Austria) |
| Bernardo item code |
05-20605 |
| Compliance |
Not subject to Machinery Directive 2006/42/EC (instrumental accessory) |
| Country of origin |
Austria |
Standard equipment
- Rigid support for internal turning gouges
- Manual 3-axis adjustment (X, Y, Z)
- Lathe tool holder mounting adapter
Optional and complementary accessories
-
Complete gouge set Bernardo (for internal turning Ø 6-16 mm)
-
Anti-vibration compensator (oscillation reducer for diameters < Ø 25 mm)
-
Specific internal turning lubricant (Bernardo, for mirror finish)
-
Set of precision stop blocks (for quick fixed depth adjustment)
Frequently Asked Questions
What precision does the Bernardo 05-20605 support guarantee?
Positioning ±0.05 mm along the three axes (X-Y-Z). This means repeatable holes to h7-h9 (ISO) tolerance. With an experienced operator and sharp gouges, you will achieve a mirror finish Ra 1.6 μm on diameters Ø 8-Ø 16 mm.
Can I use the support on NTS 200 with the same precision as on NTS 250 Pro?
Yes, the precision of the support is independent of the machine. Difference: NTS 200 has a maximum spindle speed of 1,500 rpm, NTS 250 Pro 2,200 rpm. With NTS 250 Pro you can speed up internal turning cycles by 30-40% without losing precision.
How do I calibrate the support when I install it for the first time?
(1) Mount the gouge in the support. (2) Turn on the lathe at low speed (200 rpm). (3) Slowly bring the gouge closer to the workpiece until it touches. (4) Zero the three counters (X-Y-Z). (5) Adjust manual feed: 0.1-0.3 mm per revolution for internal turning Ø < 16 mm. (6) Do a test on scrap.
What gouges are compatible with the 05-20605 support?
Tool diameters Ø 6-16 mm. Any HSS or carbide gouge in this range. Bernardo offers complete sets (05-20620 series). Gouges from other manufacturers (Index, Dormer, Widia) are also compatible, provided the diameter is within the range.
Is the support sensitive to lathe vibrations?
No. The support eliminates tool vibrations, not machine vibrations. If the lathe has high structural vibration (worn shaft, worn bearings), the support will not compensate for it. Requires a machine in good condition.
Can I also use the support for external (cylindrical) turning?
Theoretically yes (the support holds any tool Ø 6-16 mm), but it is not optimal. The support is designed for tool instability at depth (internal), not for external turning. For cylindrical turning, use the lathe's standard tool holder.
What is the setup time to install the support?
First time: 30-45 minutes (3-axis calibration + test on scrap). Subsequent setups: 5-10 minutes (depth adjustment, gouge change). Once configured for a diameter/depth, returning to that configuration takes < 5 minutes.
Does the support reduce the maximum cutting speed of the lathe?
No. The support does not limit spindle speed. However, for internal turning with rigid support, reduced speeds are recommended versus free turning: Ø 6 mm = 1,200 rpm, Ø 10 mm = 800 rpm, Ø 16 mm = 600 rpm (conservative, for mirror finish).
Does the warranty cover if the gouge breaks during use?
No. Bernardo's warranty covers manufacturing defects of the support (cracks, excessive play). Gouge breakage is the operator's responsibility (improper use, excessive speed, too strong feed). Bernardo gouges have their own manufacturer's warranty.
