The Current Situation
A large portion of work currently running on 40-taper machines falls within 30-taper capability. The challenge has been finding compact machining centers that deliver a unique combination of speed and rigidity required for most manufacturing environments.
Many machine shops optimize one characteristic at the expense of the other. Lightweight designs prioritize speed but struggle with stability. Heavy designs provide rigidity but sacrifice the ability to limit non-cutting cycle time. With modern compact machining centers, however, this tradeoff isn't always necessary.
The Case for Appropriate Machine Sizing
Running 30-taper work on 40-taper machines creates measurable inefficiencies:
- Energy consumption: Larger spindle motors and axis drives consume significantly more power per part.
- Floor space: 40-taper VMCs require 30-50% more floor space than comparable 30-taper machines.
- Cycle times: Excessive tool change and positioning time adds up quickly and inflates cycle times.
Analyzing a production setup often reveals opportunities to optimize machine sizing. Small medical components, precision fasteners, and automotive parts, for example, often don't require the horsepower or torque provided by 40-taper machines, but still require precision, consistent surface finishes, and reliable cycle times. Appropriately-sized equipment delivers these requirements while improving operational efficiency, ultimately leading to increased overall profits.
The Technical Challenge
The physics at play create competing requirements: structural design and mass for dampening vibration, efficient motion systems for productivity, thermal stability under continuous high-speed operation, and tool change mechanisms that maintain speed.
Lightweight designs achieve impressive rapid traverse and acceleration/deceleration rates, but often struggle with chatter when milling more demanding materials. More robust designs provide the stability necessary for cutting hard materials, but sacrifice the rapid positioning and accelerations that keep cycle times competitive.
The engineer question is: can both characteristics coexist without compromise?
Engineering Both Characteristics
Nomura DS compact machining centers integrate multiple features to achieve both speed and rigidity:
- BBT30 spindle with dual face contact: The BBT30 taper provides increased gripping force compared to standard tool holder interfaces. Dual contact points reduce tool deflection and minimize harmonics during high-speed cutting. This enables the machine to maintain rated spindle speeds under actual production loads, not just in ideal test conditions.
- Heavy base casting: Strategically placed structural mass absorbs dynamic forces generated during cutting and rapid positioning. The castings dampen vibration without adding unnecessary weight to moving components, maintaining thermal stability while supporting aggressive cutting parameters.
- High-speed tool changing: The drum-style automatic tool changer completes tool-to-tool changes in ~1 second to significantly reduce cycle times.
- Traverse system: Rapid traverse speeds of over 2,300 inches per minute enable quick, decisive movement between operations. Additionally, Nomura DS utilizes traditional box-way construction as opposed to linear guides for more points of contact and greater overall rigidity during movements.
These features create a compounding effect: rigid spindle and base design supports aggressive cutting parameters without sacrificing surface finish, and fast tool changes and rapid rates help maintain low cycle times in multi-operation parts by eliminating non-cutting cycle time.
Production Applications
The key is matching machine capability to application requirements. As mentioned, a lot of "small" part work doesn't require 40-taper machines, but it does require production-level performance. Predictable performance enables reliable production planning and reduces labor costs. Consistent cycle times shift after shift allow shops to accurately forecast throughput and delivery schedules. Case in point, optimizing machine size within larger production environments leads to several benefits that help shops uncover waste, leading to greater immediate and long-term profits.
Floor space efficiency also multiplies productivity gains. The same footprint that accommodates three 40-taper machines can fit five to six compact machines. When each machine runs appropriate work at production speeds, total shop throughput increases significantly. When a single operator oversees multiple compact machines instead of one large VMC, labor efficiency also compounds the throughput advantage. Once again, increasing profits.
Evaluating Compact Machining Centers
Specification sheets don't reveal production-level performance. It's imperative to evaluate whether spindle speeds are actually sustainable under cutting loads, if rapid traverse rates translate to accurate positioning, and how tool change speeds affect overall cycle time.
Well-engineered 30-taper machines handle production work within their capability envelope, enabling shop floor optimization without compromising speed for rigidity or vice versa. The value of a robust 30-taper machine is measurable: reduced cycle times, consistent part quality, extended tool life, and improved floor space utilization. As well as... you guessed it... a noticeable increase in overall shop profitability.
Nomura DS compact machining centers combine box-way construction with BBT30 spindle technology to deliver the rigidity needed for demanding materials without sacrificing speed. Follow the link below to learn more about how these machines handle production work and can fit into your shop.
