Machining Centers | Modern Machine Shop

The term “machining center” describes almost any CNC milling and drilling machine that includes an automatic toolchanger and a table that clamps the workpiece in place. On a machining center, the tool rotates, but the work does not. The orientation of the spindle is the most fundamental defining characteristic of a CNC machining center. Vertical machining centers (VMCs) generally favor precision while horizontal machining centers (HMCs) generally favor production—but these are loose generalizations, and plenty of machining centers break out of them. Another common machining center type is the 5 axis machining center, which is able to pivot the tool and/or the part in order to mill and drill at various orientations.

High-pressure coolant system is customizable to meet customer needs.

Moving from an aging set of five-axis mills to more advanced machines enabled Hendrick Motorsports to dramatically improve its engine production.

Custom workholding enabled Resolve Surgical Technologies to place all sizes of one trauma part onto a single machine — and cut days from the setup times.

Okuma America Corp. introduces the MA-4000H CNC horizontal machining center, designed with embedded cybersecurity features and “sludgeless tank” chip and coolant management technology.

Fryer Machine Systems Inc. presents its TC Series of CNC machining centers for high-performance cutting, accuracy, reliability and ease of use.

New tech center is serving as a cutting-edge showroom and a technological hub for advanced machining applications.

Chiron Group combines the best of both worlds at IMTS 2024, featuring live demonstrations of their Micro5 and Mill 2000 machines, alongside a cutting-edge virtual showroom. This innovative approach allows visitors to explore Chiron’s full product lineup without the logistical challenges of transporting large equipment.

Almost any shop can automate at least some of its production, even in low-volume, high-mix applications. The key to getting started is finding the simplest solutions that fit your requirements. It helps to work with an automation partner that understands your needs.

The GRC-R12 robot cell features a pneumatic single- or double-gripper system, as well as a drawer feed system with six drawers.

This unique fixturing system provides maximum hold with minimal clamping footprint to optimize spindle clearance and allow chips, debris and cutoffs to drop below the machining area and away from the spindle. (Sponsored)

According to Starrag, the Bumotec 191neo offers twelve separate machines based on a single platform. The system is designed to address current and future challenges for medical technologies, the luxury industry and the micromechanics sector.

Universal machines were the main draw of Grob’s 5-Axis Live — though the company’s apprenticeship and support proved equally impressive.

Explore five crucial ways equipping 5-axis CNC machines with Air Turbine Spindles® can achieve the speeds necessary to overcome manufacturing challenges.

In this episode of our shop tour series, KCS Advanced Machining takes us inside their shop and breaks down why they decided to invest completely in five-axis machining centers.

Guy Driscoll’s shop, Metal Parts Machine, is a garage shop that found success with automation. This mom-and-pop shop uses lights-out machining to run parts with 5-axis capabilities, cobots, pallet changers and more.

Three years ago, Budde Precision Machining was a well-regarded tool shop. Today, new technology has grown its reach and customer base far wider.

There are many approaches to automation in five-axis machining, and whether a shop uses robots or pallet changers, the benefits are often easier to realize than many believe.

The hybrid machine tool is an idea that continues to advance. Two important developments of recent years expand the possibilities for this platform.

After experiencing process stalls in the finishing stage of production, Bryan Machine Service designed an air-powered twin spindle and indexable rotating base to effectively double its production of small parts.

Bourn & Koch has long provided unique manufacturing solutions. However, the people who work at Bourn & Koch enable the company to deliver value to each partner they work with. From service to assembly to engineering, each step builds on the solution—helping you solve your most challenging manufacturing problems. (Sponsored)

Automatic measurement on the machine tool speeds efficiency by day and safeguards capacity at night for a small machine shop.

The D200Z CNC five-axis VMC uses an angled rotary table designed to improve rigidity and clearance for high-speed machining.

The Machined Direct Drive Pedal from DW Drums realized design improvements thanks to machining, then cost improvement as result of moving one step further.

FANUC’s IMTS 2024 booth includes real-time demonstrations that show the abilities of its equipment, including robots, controllers and machine tools.

Part of Major Tool’s 52,000 square-foot building expansion includes the installation of this new Waldrich Coburg Taurus 30 vertical machining center.

Methods Machine Tool focuses on collaboration and services at its IMTS 2024 booth.

IMTS 2024: Tsugami America showcases a multifunction sliding headstock lathe with a B-axis tool spindle, as well as a universal vertical machining center for rapid facing, drilling and tapping.

IMTS 2024: Digipas Technologies Inc. is presenting live demonstrations of the Digipas DWL1900XY two-axis vertical precision digital level, designed to enhance operational efficiency and streamline alignment processes.

IMTS 2024: Kern Precision highlights the Kern Micro HD+, a five-axis machining center with fully hydrostatic B and C axes, plus a custom turntable design.

Misapplication of these important CNC features will result in wasted time, wasted or duplicated effort and/or wasted material.

The addition of two larger gantry routers has enabled a maker of rubber belting products to produce more tooling in-house, reducing lead times and costs for itself and its sister facilities.

Erez Speiser has devoted his entire professional life to the world of machining, most notably his 20-plus years in senior management positions at cutting-tool manufacturer Iscar. When the Covid pandemic struck, Speiser began building his “Machining Doctor” website that not only provides technical information for CNC machinists, but also launched a new and unexpected phase of life for him — and a new career.

At the seminar, representatives from multiple companies discussed strategies for making orthopedic devices accurately and efficiently.

Practical work has served Bridgerland Technical College both in preparing its current students for manufacturing jobs and in appealing to new generations of potential machinists.

Decade-long, multiphase automation investments lower operating costs and maintain technology lead in an increasingly competitive global market.

What is a vertical machining center?

Most machining centers on the market feature numerical control (CNC) and serve more than one purpose. Many can perform combinations of operations such as milling, drilling, boring, tapping and reaming in a single setup. Machining centers come in three general types: horizontal three-axis, vertical three-axis and five-axis machines (four- and six-axis machines exist, but are less common).

For a vertical machining center, the X-axis controls left-and-right movement, parallel to the workholding surface; the Y-axis controls front-and-back movement, perpendicular to the X- and Z-axes; and the Z-axis controls up-and-down movement. Most machines use a fixed spindle and a moving table, or a fixed table and a moving spindle. Spindle rotation is never considered an axis.

Five-axis (and four-axis and six-axis) machines introduce additional axes that enable the table or spindle head to rotate and pivot. The A-axis involves X-axis rotation, while the B-axis is paired to the Y-axis and the C-axis is paired to the Z-axis.

Source: Machining 101: What are Machining Centers?

What is a horizontal machining center?

Machining centers come in three general types: horizontal three-axis, vertical three-axis and five-axis machines (four- and six-axis machines exist, but are less common).

Horizontal and vertical three-axis machines differ primarily in the inclination of the spindle, with the spindles of horizontal machines parallel to the surface of the machine table and the spindles of vertical machines perpendicular to the surface, although individual constructions vary widely to support different applications.

Source: Machining 101: What are Machining Centers?

What is machining center accuracy and repeatability?

Accuracy and repeatability are both vital, but these specifications can be especially difficult to determine because different manufacturers use different definitions. In general, there are three standards for accuracy: unidirectional forward, unidirectional reverse and bidirectional (which is the average of the two). Repeatability — which is the distance between accuracy samples, tested over the full range of data points — generally has four standards: forward repeatability, reverse repeatability, bidirectional repeatability and scatter.

“Lost motion,” also called “mean reversal error,” is the difference from center found when comparing marks made with forward and backward repeatability. Data collection typically repeats processes seven times, then creates a bell curve of results, calculating both the standard deviations and the mean. Different measurement standards use the standard deviations in different ways.

Source: Machining 101: What are Machining Centers?

What is unbalance?

Standard adapters and tooling are normally satisfactory at spindle speeds up to 8,000 rpm. At faster speeds, specially balanced tooling can be critical for high tolerances and surface finishes.

Unbalance is a tool’s mass times its eccentricity (which is the distance from the tool’s center of rotation to its true center of mass). Eccentricity is measured in microns and tool mass in kilograms, so unbalance is measured in gram-millimeters. ISO 16084 is the standard for setting targets for tool and toolholder balance.

To evaluate unbalance in processes, users can perform trial runs one at a time with tools balanced to a variety of different values. Such an evaluation might start at an unbalance of 10 g-mm, then progress through a series of increasingly balanced tools until it achieves proper tolerances or accuracy and surface finish fail to improve any further.

Source: Machining 101: What are Machining Centers?

How do you find eccentricity?

Eccentricity is the distance from the tool’s center of rotation to its true center of mass. Eccentricity is measured in microns and tool mass in kilograms, so unbalance is measured in gram-millimeters.

Source: Machining 101: What are Machining Centers?

What is a rotary encoder?

Machine tools use linear and rotary encoders to measure their own movements and stay on target. There are three types of encoder contacts — photoelectric (also called optical), magnetic and mechanical — but photoelectric encoder contacts are the most common.

Rotary encoders measure rotational movement drives, but spindles and recirculating ballscrews can also enable them to measure linear movements. Rotary encoders can be incremental or absolute.

Incremental rotary encoders have output signals that are evaluated by electronic counters that measure “increments.” For general length measurement applications — particularly the measure of slide movements using a recirculating ballscrew as the scale — shaft encoders that incorporate digitizing electronics are standard.

Absolute rotary encoders derive angular positional value from the pattern of a coded disc that provides values immediately after power switches on. The Gray coder and coders which use natural binary are most common, with many modern computer programs using the binary system to support high speeds.

Source: Machining 101: What are Machining Centers?

How do you improve machining center accuracy?

1. Know The Spindle

2. Measure The Process Instead Of The Part

3. Raise The Bar On Drawbar Attention

4. Control Chatter

5. Inspect With A Reference

Source: How to Improve Machining Center Accuracy