Trends in Multi-Axis Workholding and Quick Change

Various West-Bond part fixtures
Trends in Multi-Axis
Workholding and Quick
Change Fixturing
By: Paul Kieta – National Sales Manager
Jergens Workholding Solutions
Econ Vise Stackup – Typical FixturePro® 5-Axis set up with
subplate, centered riser, pallet changer and vise.
L
ong 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 reduction 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 savings at typical shop burden rates. But perhaps more importantly, that two hour savings provides 500 additional machine 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 changeover 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 accurate 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-
As Seen in CNC-West Oct/Nov 2014 issue
tail vises, collet fixtures and custom fixtures. Pallet changers 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, eliminating 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 interference 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 features 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 benefits 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 implementing these solutions at West-Bond Inc. located in Anaheim, California. West-Bond is a manufacturer of precision
wire bonding machines. Faced with small to medium production 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 freeing 750 machine hours. Gary Phillips, V.P. of manufacturing
A 250mm FixturePro pallet changer with 478 pound drill bit
direct mounted on a Matsuura MX-850 5 axis machine demo
at IMTS.
is now looking at employing pallet changer technology on
other non-horizontal applications throughout the shop.
These are just some of the new workholding technology 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
As Seen in CNC-West Oct/Nov 2014 issue