Rexroth CNC system solution controls machines for the production of jewelry

March 2016

Solanki Mechanical Works develops CNC machines for the production of jewelry. The IndraMotion MTX performance drive and control solution from Rexroth coordinates all of the work steps involved.

Indian-style rings and bangles are especially popular in the Middle East and other parts of Asia. The intricate patterns and embellishments of Indian gold jewelry are particularly distinctive. In order to satisfy the demand of large trading companies for perfect catalog goods in a reproducible quality, the industry is continuously becoming more industrial. For this reason, Solanki Mechanical Works, based in Rajkot, India, develops precise CNC machines for the automatic serial production of pieces of jewelry. The company’s regular customers include jewelry manufacturers from Singapore, Malaysia and South Africa.

Turning, milling, grooving and drilling

The new SMW-DF9 nine-axis machining center uses the IndraMotion MTX CNC complete solution from Rexroth combined with compact IndraDrive C servo-drives and synchronous servo motors. This reduces the system costs while maintaining application-suitable power and functionality. The vertical main spindle with up to 50,000 revolutions per minute, a second horizontal spindle with up to 8,000 revolutions per minute, three linear axes for the feed system, five rotating axes for multi-axis machining and a tool-changer axis are compactly arranged in the machining space. Thanks to this, the complete machining of rings and bangles with both flat and convex surfaces is not just terrifically fast, but also extremely precise – for turning, milling, grooving or drilling. The precision of the machine plays a decisive role, especially when creating delicate patterns or embellishments. The feed axis achieves a repeatability of five micrometers, even for feather-light pieces. The maximum deviation is 0.008 degrees for the rotary axes and swivel axes.

Ready for complex movements

The machining of rings and bangles with convex surfaces also requires complex calculation procedures for the circular and free-form interpolation. All of the necessary algorithms and functions such as special kinematics are available as standard with the IndraMotion MTX. The control achieves the extremely short cycle times for data exchange with the intelligent drives and peripheral such as quick I/O coupling via sercos, the open Ethernet-based real-time standard. In this way, the jewelry manufacturers can achieve reproducible quality with the shortest possible cycle times.