National Acme RAS-6
Key Specifications
Number of Spindles
Max Bar Diameter
Max Spindle Speed
Spindle Motor Power
Bar Feed Capacity
Cross Slides
Overview
The National Acme RAS-6 is a CNC multi-spindle automatic lathe produced by National Acme, an American manufacturer with a long heritage in multi-spindle screw machine technology. The RAS-6 represents the CNC evolution of the classic National Acme cam-driven multi-spindle platform, combining the proven mechanical architecture that generations of screw machine shops have relied on with modern CNC servo control for improved flexibility and shorter changeover times.
The RAS-6 configures six spindles on a rotating drum and accepts bar stock up to 52 mm in diameter, covering a broad range of component families from small fasteners up to larger hydraulic fittings and automotive housings. The CNC control system replaces the cam stack with servo-driven longitudinal and cross slides at each spindle station, allowing part programs to be stored and recalled without mechanical cam changes. This dramatically reduces setup time when switching between established part families — a key advantage for shops running multiple part numbers on a common machine.
National Acme's RAS-6 is particularly known in North American manufacturing for its rugged construction and parts availability. The machine's design prioritizes serviceability, with accessible tooling positions and a straightforward maintenance regime that suits production environments with in-house maintenance teams. Chip management and coolant systems are integrated for continuous operation, and the bar feed interface supports standard servo bar feed units from major suppliers.
The RAS-6 is found in screw machine job shops and captive production departments across North American automotive, aerospace, and industrial equipment supply chains. It excels at medium-to-high volume runs of brass, aluminum, free-machining steel, and stainless components, and is frequently chosen by shops transitioning from cam-driven Acme machines who want to retain operator familiarity while gaining CNC programmability.
Full Specifications
| Parameter | Value |
|---|---|
| Number Of Spindles | 6 |
| Max Bar Diameter | 52 mm |
| Max Spindle Speed | 5,000 RPM |
| Spindle Motor Power | 30 kW (main drive) |
| Bar Feed Capacity | 3,000 mm bar length (with automatic bar feeder) |
| Cross Slides | 6 cross slides + optional end-working attachments |
| Control System | Fanuc CNC (multi-axis multi-spindle configuration) |
| Machine Weight | Approx. 18,000 kg |
Strengths & Limitations
Strengths
- 52 mm bar capacity handles a wide range of component families in a single machine platform
- CNC control replaces cam stack for faster part changeover without mechanical adjustments
- Rugged American-made construction with strong parts availability for long service life
- Familiar machine platform for shops with existing National Acme cam machine experience
Limitations
- Maximum spindle speed (5,000 RPM) is lower than newer European CNC multi-spindle designs
- Older design lineage means some tooling and automation options are less modern than competitors
- High-volume long runs are needed to realize full ROI on a six-spindle investment
Best For
Frequently Asked Questions
01
The RAS-6 accepts bar stock up to 52 mm in diameter, which is larger than most competing six-spindle CNC multi-spindles in its class. This capacity makes it suitable for a broader range of component families including larger hydraulic fittings, flanges, and automotive housings that smaller-bore machines cannot accommodate.
02
The RAS-6 CNC replaces the cam stack with servo-driven CNC axes, allowing tool movements to be programmed and stored digitally. Changeover from one part to another is accomplished by loading a new CNC program rather than swapping and timing mechanical cams, reducing setup time from several hours to under an hour for established part families.
03
Yes, National Acme machines have strong aftermarket support in North America. Spare parts, tooling, and service are available through National Acme's distribution network, and a large installed base of Acme multi-spindles across the US means there is an active community of experienced service technicians and tooling suppliers supporting the platform.
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