In modern machine design, indexing refers to movement of a mechanical member from an initial position to a new position, starting and ending in rest. While some machines turn on and stay on, others do their work by starting and stopping, for example, bottle capping machinery and tool changers. Using the right components for the job can make light work of almost any high-cycle indexing application. Here we present some of the latest tools for your next on again, off again design task.
Compact ring indexing table
Pneumatically driven RST-series compact ring indexing tables come in two sizes, RST 18 and RST 24. Key differences include footprint (70 × 70 or 100 × 100 mm), torque (1.2 or 4 Nm), and maximum axial force on the cycle ring (1,950 or 3,400 N). Tables can cycle either to the left or right, or alternate, without modifications. Switching is performed by pneumatic actuation, and cycle types can be changed in any order, any number of times. This allows the work process to be stopped, return a few steps, and repeat the processing step if errors occur. Angle adjustment can be set to 4, 6, 8, or 12 steps and hydraulic shock absorbers are used as end position dampers in both directions. Because only the table's cycle ring rotates, it offers a large fixed central section, making it easier to add additional components and assemblies.
Make contact: Schunk Inc., (800) 772-4865, www.schunk.com
Ring table and indexer
Cylindrical-barrel cam-driven FT series ring tables are suitable for industrial automation requiring a large central hole and many stations, or programmable positioning. Other ring tables must be mounted on very stiff and precise machine bases to prevent deformation and errors; the FT's welded structure supports the output bearing and rotating ring. In addition, the camshaft and barrel cam do not protrude into the center through hole as in other designs — so the FT allows 100% use of the open center area.
Table height can vary (without changing size) and become shorter to suit the cam geometry required by the application. The tables deliver the short index angles needed for mechanically synchronized machines, and smooth acceleration with zero-backlash reduction; threaded holes and dowels are provided in mounting surfaces. These indexing tables are also compatible with servomotors and ac motors on VFD drives, and are available with a high number of stations: Stops per index angle include 6/(300° - 60°), 16/(120° - 240°), 36/(330° - 30°), and dozens of other custom combinations; cycles times are from 0.5 to one sec, at 950 to 2,690 Nm.
Make contact: CDS, Cam Driven Systems, (973) 300-0090, www.cdsindexers.com
Rotary servo positioning stage
A new version of the TMAX 5 low-profile direct-drive rotary servo positioning stage features higher load capacity and improved trajectory control. Driven by a brushless servo torque motor with an integrated high resolution rotary encoder system, the stage offers a 135-mm hub diameter platform that provides smooth, low-friction rotary motion with 360° continuous travel over a large speed range. TMAX 5 features accuracy to within 25 arc sec, less than 8 arc sec of wobble, and less than 4 µm of concentricity, making it suitable for intermittent part indexing, skew adjustment, and precise angular positioning.
Make contact: Nutec Components Inc., (631) 242-1155, www.nutec1.com
Smart Ethernet drives
A new generation of smart drives saves space for common single-axis automation and features an Ethernet Powerlink interface. New Mint Lite programming is being fitted without charge on all MicroFlex e100 and MotiFlex e100 single and three-phase drives, available in power ratings to 33.5 A. The drives can control rotary and linear servomotors, linear motors, closed-loop vector motors, and in V/Hz control modes. Mint Lite supports a range of motion programming requirements including S-ramp profiles, jog and homing movements, and registration moves — allowing these standalone drives to handle tasks such as cutting or feeding to length and indexing axes.
Make contact: Baldor Electric Co., (479) 646-4711, www.baldor.com
Stainless steel indexing belts
A new line of indexing belts suits high-speed indexing conveyors used to assemble plastic spray bottle caps and other multi-component assemblies. These stainless steel belts resist stretching, provide repeatability, and facilitate exact positioning of tools and parts. Unlike traditional conveying systems, these belts can be mounted vertically: This allows manufacturers to use both sides of the conveyor. These continuous-length belts improve consistency, minimize debris buildup, and eliminate shutdowns associated with cleaning other types of systems.
Make contact: Belt Technologies, (413) 786-9922, www.metalbelts.com