Before the new rotary tables-with rotary plate sizes from 160 mm to 320 mm-were sold to customers, Eppinger tested them first in-house.
Eppinger, manufacturer of tool systems and toolholders, has introduced a range of rotary tables for machine tools. The rotary tables are available with rotary plate sizes from 160 mm to 320 mm and are suitable for both initial installation and retrofitting of vertical and horizontal milling machines.
"We have used more than 30 rotary tables of different brands at our production sites for many years," said Managing Director Uwe Eppinger. "That is why we are well aware of the pros and cons of installation, flexible application, maintenance costs and decreasing accuracy."
The increasing degree of automation in Eppinger's own production also requires a more compact design of the rotary tables, which allows the use of suitable clamping devices without restricting the required travel distance of the machining axes too much.
"Although the existing market is already highly competitive, Eppinger is venturing into this segment. Our rotary tables differ significantly from existing solutions. They have been used for some time in our own manufacturing, where they gradually replace third-party products," explained Mr. Eppinger. "The reason is that for our own production of tools, wheel gears and gear units, we need rotary tables that can be quickly and precisely positioned, that are extremely compact and suitable for fine grinding as well as for rough milling operations. In addition, they should be easily integrated into existing vertical and horizontal machining centers and used there in a flexible way. Since we could not find suitable rotary tables on the market for our specific requirements in this specific combination, we developed them ourselves."
The company was able to rely on its many years of experience in the design and manufacture of high-precision components for machine tools as well as in drive technology. "The high requirements for positioning accuracy and compactness could only be achieved with a preloaded drive system and integrated angle measuring system. When developing the rotary tables, we thought very hard to come up with an innovation for the market," said Eppinger.
New Concept of Rotary Tables
"An essential distinguishing feature of the Eppinger rotary table is the preloaded, backlash-free twin-engine drive that allows quick indexing even without clamping. Furthermore, an integrated angle sensor on the rotary plate ensures the highest positioning accuracy even with changing loads," said a company spokesperson. Although this principle is already used for larger rotary tables, Eppinger found a practical solution to implement this also for rotary tables with rotary plate sizes from 160 mm to 320 mm. Although the angle measuring system integrated into the housing measures the angle directly on the rotary plate and compensates for mechanical interferences, the preloaded drive makes it possible to set up a high control loop gain. "Only in this way is it possible to make the bidirectional positioning extremely precise in the angular seconds range," said the spokesperson.
To integrate into already existing machines, the company relies on a plug & play concept. This applies both to the connection of the rotary tables within the processing area of the machine (via splash-proof plug connector) as well as to the electrical connection to the machine control system via a specially developed machine interface unit. Thus, the rotary tables are suitable both for the initial installation as well as for the retrofitting of vertical and horizontal milling machines. When placing the rotary spindle, precision classes from 3 µm down to 1.5 µm in lapped or ground execution are available, both for radial and axial run-out.
"An obvious benefit is the multi-disc clamp that is installed as standard," said Eppinger. "It ensures strong clamping at high machining forces since it clamps the rotary plate directly. Apart from a high clamping torque, a high torsional rigidity is achieved, which in turn ensures high surface qualities with changing cutting forces. Based on our experience, this aspect is often disregarded since high clamping torque does not mean high clamping rigidity at the same time."
The rotary plate can be exchanged precisely using a taper planar support with radial and axial change accuracies of 3 µm and more. As a result, workpieces from manufacturers such as Hainbuch, Lang or Erowa can be precisely clamped over T-slots, short taper clamps or workpiece clamping systems. "In this case, we rely on a system similar to that of our toolholders with Prexi-Flex spindle interface," said the spokesperson. "However, when using the rotary tables-in contrast to the Prexi-Flex interface-it is the planar support that is rigid and not the cone, which stays flexible due to a machined groove. This guarantees a stable taper planar support where a very high change accuracy is achieved at the same time."
Flexible Plates and Simple Installation
Eppinger has also integrated an exchangeable plate system into the rotary tables. Thus, the customer has the option when placing an order or even later to choose whether he or she wants to have the rotary table equipped with rotary plate, plate with T-slots or with a spindle nose. The buyer can also decide whether a left-sided, right-sided or elevated rotary table is preferred: the rotary table can be easily turned due to its symmetrical housing shape.
"And finally, problem-free installation of the rotary tables is ensured due to the specially developed plug & play connection concept," said the spokesperson. Since the rotary tables are supplied with their own preconfigured axis controller, no additional axis controller or axis controller configuration by a service technician is required on the machine side during installation.
Maintenance Friendly
"The Eppinger rotary tables are also particularly easy to maintain," said the spokesperson. "In contrast to known solutions, clearance and wear are automatically compensated over the lifetime, which considerably increases availability and service life of the product." Optionally one or more rotary axes can be connected to one machine with the innovative machine interface unit. If the rotary table is to be used on another machine, no reconfiguration of the machine control system is needed, which reduces machine downtime and involvement of service technicians. Workpiece clamping systems and material feeding systems can be controlled via the machine interface unit without having to additionally activate M functions.
For more information contact:
Eppinger GmbH
www.eppinger.de
EXSYS Tool, Inc.
11654 Corporate Lake Blvd.
San Antonio, FL 33576
800-397-9748 / 352-588-4345
sales@exsys-tool.com">info@eppinger.de
www.eppinger.de
EXSYS Tool, Inc.
11654 Corporate Lake Blvd.
San Antonio, FL 33576
800-397-9748 / 352-588-4345
sales@exsys-tool.com
www.exsys-tool.com