|
Although
grinding is one of the most precise manufacturing operations, it is
the source of a lot of grit and sludge, which means doing
considerable maintenance to keep the grinder running. A grinding machine
can achieve tighter tolerances and better finishes than other
processes, such as turning and milling. However, it must operate in
one of the shop’s harshest environments: one that can wear out a
machine quickly if it is not given proper attention.
In maintaining most
conventional grinding machines, access is the number one problem,
according to Norbert Beadel, president of R.T. Industries (RTI;
Santa Ana, CA). RTI was formed about three years ago, in conjunction
with a toolmaking company, Cutting Tool Industries. CTI has been in
business for about 33 years and manufactures carbide burrs, files,
and endmills in a 10,000 sq.-ft. facility that employs about 51
people. RTI operates out of an 8,500 sq.-ft. facility nearby with an
employment of about eight people.
CTI’s production
line features about 45 machines, including Walters, Unison’s, and
Anka’s. “We owned what was already available on the market,” Beadel
reports, “and found that by using this equipment that it wasn’t
really designed by toolmakers, but by machine tool builders. That’s
why I’m in the business (developing Toolmaster, an improved grinding
system): they (the other grinding machines) forced me! The last time
that this happened properly was the Cincinnati No. 2 in the 1950s.
It was a great grinder, and it still is; simple in concept, to
understand and use.”
When CTI installed
other grinding machines on its production line, it was usually
confronted with a long learning curve for using machine features
that were not even needed. This prompted CTI and Beadel to start
developing their own equipment about 11 years ago. After eight years
of developing improved approaches to grinding processing, centerline
concepts, vibration, and table movements, the project culminated in
the formation of RTI and the creation of Toolmaster. This innovative
grinding machine is the result of resolving the problems experienced
by CTI in making tools with the other grinding systems.
Toolmaster’s
primary focus was the high-level production of quality cutting tools
with low maintenance. Throughout the development period for
Toolmaster, CTI continued to be an active manufacturer of cutting
tools. This provided the company with the advantage of perfecting
the machine’s design by actual application in production. Later,
with Toolmaster in production at RTI, the grinding machines in use
at CTI were able to demonstrate that the design could deliver what a
toolmaker needs to use, not just what a machine tool builder wants
to sell.
To date, 33
Toolmasters have been produced and installed in the field. Among the
supporters and users of this new grinding machine is Criteria
Machine Works (Costa Mesa, CA). Another Toolmaster user is a
high-volume manufacturer of center drills and other tools. In
addition, RTI and CTI have 22 versions of the grinding system
in-house, running tool production on two shifts per day, five days
per week (sometimes six). The company is presently consolidating its
operation at its five-building facility and expanding the
machine-building facility, which is currently running at capacity.
The latest development for Toolmaster is the addition of an
integrated SCARA robot loading system.
Design Features
for Profitable Toolmaking
Among the grinding
machine’s many features, accessibility was given the highest
priority by providing doors that open 260° for cleaning its
interior. In addition, the Toolmaster uses a profile rail system
with lubrication under pressure to eliminate metal-to-metal contact
and friction, unlike the traditional V-grooves used on the ways and
table guides of other machines.
Another standard
feature is the cooling and environmental system, which is built-in
to maintain a lower footprint. Mist collection and coolant return
systems are integrated and self-contained in one package. They are
accessible for filter change, and the tank rolls out for quick
cleaning. Although most users also have their own coolant
filtration, the Toolmaster has a tri-baffle coolant system. For
carbide or steel use, the grinder’s tank can be replaced with a
fresh tank once a month or as needed. A centrifuge cleaning system
for the coolant is available as an offline option or as an
integrated system.
Grinding wheel
choice for the Toolmaster is generally a matter of personal
preference and the nature of the application. With CNC (computer
numerical control) grinding, diamond wheel life is about 100 times
that of conventional grinding wheels. According to Beadel, “It
really doesn’t matter to Toolmaster which wheel is used. We usually
recommend buying a diamond wheel based on price. The grinding
machine is so sophisticated that you can use a less expensive wheel
and get good results.”
Toolmaster is
designed so that its operation and use is intuitive and simple to
understand. When a toolmaker starts working with the grinding
machine, it makes sense. Beadel notes, “There are a number of
grinding systems that other machine tool builders developed that are
pretty good. However, in the applications that Toolmaster deals with
(e.g. cutting tools), the concepts developed by RTI are true to the
form for producing cutting tools. In dealing with tool builders for
about 11 years, and with Toolmaster in development for eight years,
we learned a lot from using other people’s equipment and what needed
to be improved.
Usually, in the
cutting tool industry lot sizes for center drills and similar tool
types are 120 – 150 units. Most other tools (˝" endmills, for
example) are produced in lot sizes of 500 – 1,000. Because of this
kind of production flow, and the large variety of tool types
produced, tearing down and setting up the grinding machine is a
frequent, continuing activity. This makes accessibility and
maintenance even more critical, and these cutting tool makers
appreciate Toolmaster’s advantages.
In addition,
Toolmaster has been able to demonstrate a competitive ROI (return on
investment) according to industry pricing, in contrast to a number
of other comparable machines. Comparative figures based on reported
cycle times for other grinding machines are difficult to verify,
since these statistics are highly dependent on the conditions: kind
of wheels used, how the coolant is directed at the wheel, kind of
coolant used (oil or water), etc. R.T.
Industries
- October 2000
|
