As Seen in CNC-West Oct/Nov 2014 issue

Trends in Multi-Axis Workholding and Quick

Change FixturingBy: Paul Kieta – National Sales Manager

Jergens Workholding Solutions

Long term industry trends to lean manufacturing, shorter lead times, smaller batch sizes and more set ups have led to the growing use of 5 axis and

multi-axis (3+2, 4+1) machines and accessories (primarily for positional machining) to eliminate multiple operations. And, after putting significant effort into cycle time reduc-tion through advanced application of cutting tools, users are also paying more attention to set-up time reduction and quick change fixturing to improve their operations.

The cost savings associated with quick change fixturing can be substantial. Eliminating two hours of set up time a shift can provide approximately $50k in overhead cost sav-ings at typical shop burden rates. But perhaps more impor-tantly, that two hour savings provides 500 additional ma-chine hours/shift per year in available machine time.

Typically, after acquiring their first 5-axis machine it’s likely a user will add another 5-axis or convert a vertical machining center into a 3+2 machine by adding an indexer or a rotary table. Therefore the goals for any multi-axis workholding are; rigidly hold different work pieces in the 5 axis “sweet spot,” provide rapid set-up, quick part change-over and portability from one machine and set up to another as parts and machines are added.

System requirements for flexible multi-axis workholding include a subplate for the machine table featuring an ac-curate quick change locating system, a variety of risers for flexible locating of the workpiece (or multiple work pieces) at the proper height, and top tooling – including vises, dove-

Various West-Bond part fixtures

Econ Vise Stackup – Typical FixturePro® 5-Axis set up with subplate, centered riser, pallet changer and vise.

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As Seen in CNC-West Oct/Nov 2014 issue

tail vises, collet fixtures and custom fixtures. Pallet chang-ers are also emerging as a key technology. A pallet changer provides rapid part change over with repeatability of .0003” or better.

With a pallet changer, besides rapid part change during machining, they also provide the ability to accurately locate the part for secondary machining operations or first article inspection, while being held in the initial clamping, elimi-nating many positional issues associated with moving a part through multiple operations. Pallet changer mounting studs, in many cases, can also be mounted directly to a part and direct mounted to the changer. This eliminates any interfer-ence caused by vise jaws or dovetail clamps. Parts can also be indexed in the pallet changer without removing the part from the fixture to machine 5 faces of the part.

Jergens FixturePro® line of 5-axis and multi-axis tooling is designed to meet these needs. It is comprised of modular, standard components that can be sized for every machine or workpiece and top tooling options for part clamping. It fea-tures Jergens QLS, quick locating system for rapid set up and features the Drop and Lock® pallet changer.

An emerging trend is also for the use of pallet changers in horizontal and vertical machining operations, often with parts mounted in custom fixtures. This provides the ben-efits of accuracy, repeatability, portability from machine to machine while holding the part in its initial clamping as in 5-axis applications. Another trend is the combination of quick change fixturing technologies to provide an optimum workholding solution.

These trends can be illustrated by the results gained im-plementing these solutions at West-Bond Inc. located in Ana-heim, California. West-Bond is a manufacturer of precision wire bonding machines. Faced with small to medium pro-duction runs, frequent, lengthy set-ups on vertical machining centers and the need to maintain global competiveness, they looked to change their methods.

Moving from vertical to horizontal machining, they also took a fresh outlook at their workholding. One solution was to use custom workholding columns that employ multiple quick change fixturing technologies. This included ZPS, or Zero Point technology, combined with the use of Drop and Lock® pallet changers holding custom part fixtures.

Using ZPS as the base, West-Bond can rapidly convert how the column is configured based on the parts to be run, without investing in a custom column for each operation. They can employ pallet changers, dual station soft jaw vises or mount parts directly to the ZPS receivers with locating studs mounted into part blanks based on need.

Using Drop and Lock® pallet changers, parts formerly run on vertical machines are being converted to custom Drop and Lock® fixtures mounted to the column. This process has “virtually eliminated” set-up time when changing over parts. Parts are also indexed on the pallet changer to machine all five faces. Part exchanges in the fixtures are handled off line, while the machine runs the next batch. Set up time has been reduced from an average of three hours to minutes. This has resulted in overhead savings of $68,000/year, while free-ing 750 machine hours. Gary Phillips, V.P. of manufacturing

is now looking at employing pallet changer technology on other non-horizontal applications throughout the shop.

These are just some of the new workholding technol-ogy available today. The bottom line – whether acquiring new equipment, changing machining processes or moving to 5-axis and multi-axis machining, be sure to consider the latest in workholding technology to gain additional savings and productivity and make the most of your machine tool investment.

West-Bond ZPS column model with Drop and Lock® fixture

plates and vises

A 250mm FixturePro pallet changer with 478 pound drill bit direct mounted on a Matsuura MX-850 5 axis machine demo

at IMTS.

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