Nomura NN-27 II

The NN-27 II incorporates several generational improvements over the original NN-27: (1) Updated spindle bearing cartridges with improved preload consistency, providing better radial stiffness and reduced thermal growth over extended production runs — diameter repeatability improves from approximately ±0.008 mm to ±0.005 mm in hot-running production; (2) New-generation CNC axis servo drives with 30-40% faster axis acceleration, reducing non-cutting time during tool approach and retract sequences; (3) Standardized live tooling spindle interface replacing a proprietary system — improves commercial tooling compatibility and reduces tooling cost by 20-35%; (4) Updated Fanuc 30i control with improved axis synchronization for live tooling coordination; (5) Improved chip conveyor design reducing chip packing in the work area for steel components. These improvements reduce total cost of ownership versus the original NN-27 while maintaining the same production envelope.

The NN-27 II's 27 mm bar capacity covers the following common hydraulic fitting sizes (by approximate bar stock diameter required): NPT 1/8" body — 18 mm stock; NPT 1/4" body — 22 mm stock; NPT 3/8" body — 27 mm stock (at NN-27 II limit); BSP 1/4" body — 20 mm stock; BSP 3/8" body — 25 mm stock; JIC 37° #4 (1/4" tube) — 22 mm stock; JIC 37° #6 (3/8" tube) — 25 mm stock; SAE O-ring boss #4 — 20 mm stock; SAE O-ring boss #6 — 24 mm stock. The NN-27 II covers NPT 3/8" and all smaller sizes, JIC #6 and smaller, and the full BSP range through 3/8". Larger sizes (NPT 1/2" and up, JIC #8 and up) require the NN-32 or NN-38.

Yes. Live tooling at cross-slide stations on the NN-27 II enables hexagonal milling for wrench flats on fitting bodies and valve housings. Approaches include: (1) Live milling spindle with end mill using synchronized C-axis for hex indexing — produces precision hex flats at ±0.05 mm across-flat tolerance; (2) Form milling with hexagonal form mill in a single plunge — faster cycle time, ±0.08-0.12 mm tolerance; (3) Polygon milling using synchronized speed ratio between main spindle and live tool spindle — suitable for high-volume hex features. For standard hydraulic fittings, the cross-milling approach at a dedicated live tooling station adds approximately 2-4 seconds per cycle. Across-flat tolerances of ±0.05 mm are achievable for standard wrench-flat fittings; tighter tolerances for precision valve bodies may require offline sizing operations.

The economic crossover depends on part value and setup cost. Rough analysis: NN-27 II setup cost (4-8 hours at $80-120/hour loaded rate) = $320-960 per setup. CNC turning center setup (1-2 hours) = $80-240. At a typical hydraulic fitting value of $8-25/piece, setup cost becomes less than 2% of order value at batch sizes of 2,000-5,000 parts. At those batch sizes, the NN-27 II's 3-5x throughput advantage versus a CNC turning center is relevant: for 5,000 fittings, the NN-27 II completes the run in 1-2 hours vs 4-8 hours on a turning center. True economic justification for the $420K-$780K capital: sustained annual programs of 500,000+ parts across 3-6 product families, where setup amortization is negligible and the throughput advantage drives meaningful cost-per-part reductions.

The NN-27 II's standard tooling configuration: (1) Longitudinal tools — one per spindle (6 total), typically used for face turning, center drilling, profiling from the front face, or drilling with rotating spindle and stationary drill; (2) Cross tools — up to 2-3 per station (12-18 total), used for OD turning, grooving, threading, form turning, and live milling/drilling; (3) Back working attachment (optional) — additional 4-6 tools for parted-end operations (back face, back drill, back thread). A typical complete setup for a hydraulic fitting: station 1: face + center drill; stations 2-3: OD turning; station 4: cross-drilling/boring; station 5: threading (live or fixed thread die); station 6: grooving + cutoff. Back-working: back face + back drill. Total tooling for this configuration: 14-18 tools active simultaneously across all stations.