Ballscrew Driven Motion
Northwood employs the most respected mechanical drives in the machine tool industry--ground,
precision, reciprocating ballscrew systems. These drives are renowned for their
ability to carry extremely high loads smoothly, efficiently, and quietly with little
or no maintenance. This means that little or no power is consumed by the inefficiency
of the drive system, leading to more accurate servo control and more work done at
the tool.
In addition, ballscrews are the number one choice for eliminating backlash in linear
drive systems. Unlike various forms of rack and pinion systems, ballscrews use rolling
elements in raceways thereby eliminating the sliding that occurs during engagement
and disengagement. This can be done using the elastic deformation properties of
the rolling elements using negative clearance raceways or by using offset races
in the ballnuts themselves.
Designers have tried to devise various tricks to circumvent these issues because
rack systems are cheaper. One of the most common rack designs uses opposing pinions
with some sort of pre-loadable linkage such as a chain. The problem with that design
is if they are adjusted too low or high or the backlash is too high, the wear becomes
excessive and efficiency plummets. Another problem with rack systems is that the
relationship between the pitch circle of the pinion gear and the pitch line of the
rack is very critical both for positioning accuracy and backlash. If those two pitch
components are not perfectly tangent, then the system will detect binding (when
the pinion tries to travel too deep) or release (when the pinion leaves the pitch
line slightly and creates "play"). In either circumstance, the linear speed of the
system will fluctuate.
Ballscrews are an integral unit by design, and thus retain a consistent working
relationship; wherever the screw is mounted and aligned, that’s where the nut goes.
Because Northwood utilizes a rotating-nut design on most of its system, the screw
can be pretensioned, fixed, and laser calibrated for long-lasting, world-class performance.
If you examine any high-end machine tool, five-axis CNC, or precision grinding machine
in the world, you will likely find a precision ballscrew drive.
Fanuc Motion Controls
FANUC is the industry leader for high-performance, high-reliability CNCs. From
the 0i, the worlds most popular control with more than 400,000 units in service
to the 30i, one of the most innovative controls with dual processing capabilities,
Northwood is capable of integrating the right control for your application.
Using advanced microchip technology, Northwood’s CNCs are compact yet rugged. The
advantages of Northwood’s precise, high-performance digital servo systems are evident
in the quality of every part that you make. Northwood offers a standard 18-month
warranty on its machining centers, but with an average fourteen-year mean time between
failures, it will probably be a long time before you need to take advantage of Northwood’s
technical and replacement part support.
Fanuc offers a wide range of value-added services that can lower your overall
cost of ownership. Fanuc is loaded with the following premium features to ensure
maximum productivity:
- Multi-language support
- Simple programming and operation with manual guide 0i
- Operator friendly graphic display for visual part program verification
- Extended help functions and alarm/operation history
- High-speed machining for making higher quality parts faster
- Tool life management for maximum machine utilization
- Cutter compensation for print dimension data input
- Canned cycles for simplified part programming
- Custom Macro B for extending existing canned cycles, or creating new ones
- Rigid tapping for high-quality tapping with low-cost, solid taps
- Skip cycle programming for on-machine probing