O&MM Fabricator - September/October 2015 - (Page 59)

Cutting-Edge Laser Machining Latest Machine-Generation with Cost-Efficient Mechanical Transmission Designs ALEXANDER HACK, MARKET DEVELOPMENT MANAGER, KOLLMORGEN, RATINGEN BaseD in chennai, proteck was established over 25 years ago and is now one of India's leading production machinery suppliers; distributing, supplying and manufacturing a wide range of printing machinery, machine tools, metal cutting & forming equipment and CAD/ CAM software throughout its home market and in more than 20 countries world-wide. Today, Proteck develops its own special purpose laser-cutting and CNC machine tool range. The Proteck range Proteck's evolution to manufacturing its own machines began with high specification CO2 equipped three-axis laser cutting machines with flying optics that cater to a wide range of flat sheet material. These small footprint machines originally included cast-iron beds and single lower axis geometry that allowed open three-side access for flat sheet sizes around 2.5 x 1.5 metres. Bosch rexroth or Siemens CNC controller options fully integrated with Proteck's highly-developed MetaCAM CAD/ CAM software allows ease of use for all types of sheet metal cutting. As a development from this machine, Proteck introduced a 'Plug and Play' model for job and fabrication shops that included all of the features of the previous machines but used a much lighter and lower cost welded frame construction. Proteck then began its marketing concept that a laser cutting machine should be no more complicated than an office laser printer. As part of this continued initiative, its designers looked hard at the transmission mechanics. Precision ground ballscrew cost for a 2.5 metre travel range is expensive, and the single-axis/single-screw design with its overhung load requires more sturdy and costly linear motion guide bearings for adequate support. Furthermore, to maintain a good dynamic performance, the ballscrews need to be large in diameter to allow high rotation speeds - which increases servo motor and servo drive size. With the need to produce even longer travel machines that could provide larger flat sheet work, Proteck and Kollmorgen EU began to address some central questions: * How to maintain the +/- 10 micron bi-directional repeatability performance and up to 110 m/min max linear speed, required of the machines? * How to reduce the power requirements and provide increased efficiency? * How to further drive down powertrain component costs? The result was the introduction of an innovative rack and pinion drive system for the long-travel lower axis of the machine for a new three-axis bridge laser machining centre which includes two synchronized lower X-axes supporting a gantry y-axis and a vertical Z-axis. rack and Pinion with Direct Drive Motor and innovative Preload The initial conception looked at linear motor technology for the long-travel dual synchronized X-axis, but the cost for this was too high for Proteck's target market. Proteck's rack and pinion design concept was thus developed with the awareness that backlash and repeatability performance would need to be achieved using a novel approach. The answer was to design the pinion-to-rack transmission around the Kollmorgen KBM series direct drive motor. Directly Coupled The KBM's separate rotor and stator packages are now supplied in kit form and directly mounted on the machine by Proteck within their own bearing system and protective cover with power and encoder connectors built-in. The mounting arrangement directly couples the large diameter pinion shaft to the rotor as a single solid assembly restricting lost motion and potential unwanted harmonics that a flexible coupling may give rise to. The resulting design has been field-proven for extremely low backlash and has a dynamic and throughput specification which is very close to linear servo motor performance. The rack and pinion system is also resilient to debris and does not require the degree of protection that a linear motor system would necessitate for a laser machining environment. With the success in Performance and reliability, Other Developments have followed This rack and pinion system has less parts, is more energy-efficient and delivers higher speed and accuracy, reducing the backlash and lost motion to well below the desired specification. As an intrinsic part of the design, Kollmorgen S700 servo drives with their multi feedback capability and are used with both resolver feedback, mounted on the KBM motor for commutation, and magnetic linear scales for the position loop. The feedback protocol is SSI absolute, EnDAT or alternatively BiSS to suit a choice of CNC controllers with set-up and monitoring via EtherCAT which is integrated in all S700 drives. Many optional features of the advanced servo drive may be included in the machine specification. These include STO (Safe Torque Off) for SIL 2 and 3 safety standards, and Ethernet connectivity for setup and monitoring. EtherCAT is also available and will be integrated in future machines for axis synchronization. September/October 2015 * O&MM Fabricator | 59 PrOduCTS WHAT'SHOT?

Table of Contents for the Digital Edition of O&MM Fabricator - September/October 2015

Message from Allyn Moseley
Message from Marbella Miller
NOMMA Network
NOMMA Educational Foundation
Until recently, Tampa’s residential construction market had been mostly remodeling work. Now, multi-billion-dollar custom homes has business booming for Vasquez Custom Metals.
2015 Top Job Gold Winner for Forged Fabrication: Make it Like This, But Different
4 rules for hiring & retaining your best employees
Intentional networking: 9 effective and efficient steps to success
Supplier Members
New NOMMA Members
Industry News
25 years later, an ornate Gazebo is finally used for its intended purpose.
Products & Services Marketplace
Index of Advertisers

O&MM Fabricator - September/October 2015