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Oxford Engineering takes lean manufacturing forward
with EdgeCAM multi-task Mill/Turn machining
Oxford Engineering Limited is a 100-person, £8m turnover,
“one-stop shop” contract manufacturing business long
established in Abingdon, Oxfordshire. It also has a recently opened
facility in Estonia — Oxford Engineering Eesti OÜ.
 The
success of the company can be appreciated in a number of ways. One
is reading its annual reports. There has been solid business growth
over a period when many engineering firms have struggled even to
stay alive. Another is visiting the facility in Abingdon. Oxford
Engineering practises lean manufacturing, and it’s not too
fanciful to feel that everything — even the buzz of controlled
activity in the workshops — demonstrates this.
The company concentrates on smaller runs,
not high volume, for an extremely diverse range of markets. The
demanding world of aerospace is one; others include medical, entertainment,
and power generation. Typical batch size is between five and 50,
and enormous efficiency, discipline and flexibility are pre-requisites.
For a new commission at Oxford Engineering, paperwork flies around
in all directions. Materials — titaniums, stainless steels,
aluminiums, plastics — have to be ordered in rapidly, special
tools may need to be ordered or jigs or fixtures manufactured, sub-contracting
of outside processes such as anodising or vacuum braising has to
be administered. “Total manufacture” is important for
many of the company’s customers who are happy to be relieved
of the control burden by Oxford Engineering and its effective systems.
Together with a quality product, time is
of the essence, because time equals cost. Cutting timescales and
costs for customers is demonstrably a major component of the Oxford
Engineering achievement. Working to smaller batch sizes like this
has its obvious difficulties, but getting it right — and keeping
the manufacturing time down — brings rewards.
An important company characteristic is openness.
As part of this, Oxford Engineering publishes its strategies on
its website. One of them is “To operate towards the leading-edge
of technology and to invest sufficiently in our people and equipment,
to ensure a high level of competence.” An investment made
during the 1980s was in the company’s first CAM (Computer
Aided Manufacturing) products; two decades later Oxford Engineering
is still an enthusiastic user of EdgeCAM software by Pathtrace Engineering
Systems Limited.
Another of the company’s strategies
— there are 12 in all — is “Continual cost reduction
and efficiency improvement will be aggressively pursued by all”.
So how is EdgeCAM helping the company to achieve its aims?
Towards single hit machining
Jon Raimbach, engineering manager at
Oxford Engineering, comments: “We all recognise the fact that
we can’t stand still, otherwise we will stagnate.” Their
dynamism is exemplified by the company’s early adoption of multi
task machining — mill/turn operations carried out by a single
machine tool.
This relatively recent purchase is a Yamasaki/Mazak
Integrex MS200 twin spindle turning and milling machine. The benefits
of these new generation combined mill/turn machines are well known:
reduced fixturing costs, no downtime/setup time between milling
and turning operations, increased part accuracy because of the tighter
tolerances that can be held between milling and turning operations,
and floor space freed in the workshop.
The fact is, though, that unlike previous
generations of machine tools, multi task machines cannot program
themselves to achieve anything like maximum efficiency. Considerable
software capability is needed to master the complexities of spindle
synchronisation; collision avoidance is another major consideration.
Simultaneous machining optimisation of all the various elements
of the machine is absolutely crucial if the full benefits are to
be achieved and the ROI period of the machine tool minimised. EdgeCAM
offers unique capability in programming multi task machines like
the Integrex.
Taking advantage
For all that has changed since the 1980s,
however, certain factors have remained common. The need has always
been to achieve greater accuracy and higher quality while reducing
lead times and speeding up the production cycle time. The trick, if
it can be called that, for companies such as Oxford Engineering is
to spot and deploy the best means towards this.
The initial CAM software purchase by the
company no doubt had a similar “this is the trend, and we’re
going for it” feeling about it that decisions about multi-task
machine tools have at present for forward-looking firms.
Today, the EdgeCAM software used by Oxford
Engineering includes EdgeCAM Solid Machinist, EdgeCAM Part Modeler,
EdgeCAM Advanced Production and EdgeCAM Turning.
 “User
friendly and functionality fine!”
Jon Raimbach describes EdgeCAM as “well
proven software that suits our needs admirably”. Functionality
is obviously part of this, and is important for a company where “We
pride ourselves on doing awkward parts that others might struggle
with or shy away from.”
Another key aspect is ease of use. Here
EdgeCAM scores highly. It has done so increasingly during the ongoing
development and considerable change in the software that Jon Raimbach
has watched, initially though not latterly as a user of EdgeCAM
himself. “It was always easy to use, but now, using mouse
and pictures, it’s a lot easier to do something that is actually
quite complicated.”
In the earlier days the company trained
its programmers from those who worked on its own shop floor. “They
knew nothing about CAM. They went through the standard training
course at Pathtrace, and got my knowledge too.” Of two men
in this category, he says “They picked it up really well —
I suppose an advertisement for how easy it is.” Years on,
one of these programmers has recently been through sub-spindle and
B-axis advanced turning training in order to program the new Mazak
Integrex.
Jon Raimbach likes to compare views on these
matters, and says he is encouraged by hearing similarly positive
EdgeCAM messages from people with experience of other CAM software.
An opportunity for comparisons arises, albeit infrequently, when
there is a personnel change among Oxford Engineering’s three
programmers. Invariably when someone new joins the company and the
topic is discussed he encounters agreement with his own view of
EdgeCAM as generally the best. He sums it up as “User friendly
and functionality fine!”
Jon Raimbach also comments favourably on
the way Pathtrace has supported his company over the years. There
may also have been a certain synergy between Oxford Engineering
and Pathtrace based on always working forwards — seeking to
stay ahead of the game. He says: “They’ve got a good
development team there, and they’re going on developing it.”
Massively reduced complexity and lead times
Chris Budd, Oxford Engineering’s
sales and marketing director, is also highly complimentary about EdgeCAM
vis-à-vis its competitors. “It’s simpler to use,
and better.” An additional reason for his belief is summed up
by the word associativity. “You can translate designs from CAD.
Solidworks and Unigraphics come straight in” — as do those
created using many other leading CAD packages.
Oxford Engineering offers its own design
service, but EdgeCAM’s ability to take in and make direct
use of customers’ CAD designs is an important aspect of the
company’s offering. Not only is there an image aspect to this,
there is also something much more fundamental.
Jon Raimbach explains: “EdgeCAM plays
a massive part in reducing complexity and timescales”. Customers
can send in either a CAD drawing or a model to Oxford Engineering.
Then, “We can use EdgeCAM quickly as well as knowing we have
the process in place for the reduced batch size. So we can get the
parts through quickly, saving money, and reducing human error.”
Oxford Engineering has recently purchased
EdgeCAM Part Modeler, and he says: “It’s very easy to
create models, so that even if you are doing a simple part, it’s
nice to create a model to look at.” He notes that more and
more of their customers are also using solid modelling software
for part and fixture creation.
Some of the company’s customers are
not very interested in the software aspects of how parts are made,
only in getting their own parts produced. Others, says Jon Raimbach,
are impressed by the fact that Oxford Engineering can take their
solid model and use it to create the cutter paths.
A demanding customer
If you pay for something, you should
get your money’s worth, is another Oxford Engineering theme,
and this applies to CAM software as well as anything else. Jon Raimbach
says: “I am quite demanding in that I like post processors to
give all the information possible, so that there is minimal editing
of the programs after the event. The reason for that is that if there
are any changes or edits to be made, then the source file has got
all the information.”
He knows that some users of CAM software
use it “just to do the awkward bits”, and then type
in the rest themselves, or edit at the machine, but as he points
out, this calls for full understanding and skill on the shop floor.
“If you have less experienced people at the machines, you
don’t want to be paying them to learn the software”
— and if you’re Oxford Engineering, you don’t
have the time luxury for that anyway. So he expects the programs
to “have every i dotted and t crossed”.
Telling figures
A telling set of figures was outlined
by Patricia Hewitt MP, Secretary of State for Trade and Industry,
in 2003 when she visited Oxford Engineering after its involvement
in a project with the DTI’s Manufacturing Advisory Service.
The aim had been to improve productivity, and Patricia Hewitt quoted
the company as having achieved savings of 75% in process travelling
distances, 35% in set up times, 29% in lead times and 11% in space
utilised.
Oxford Engineering keeps solidly to its
improvement strategies. Jon Raimbach comments that EdgeCAM has to
work hard at Oxford Engineering — and that it does, to the
extent that the company wouldn’t like to be without it. “You
don’t have the verification if you are manually typing. It
is far easier to make mistakes, and you can’t easily see 3-dimensional
objects as you can now.”
His own figures are interesting too, taken
in combination with all the qualitative benefits of EdgeCAM, and
especially in the light of the differences that the right software
can make to multi task machining. “Looking through some timesheets,
on average it looks as though we take between two and six hours
to program new parts using EdgeCAM,” he finds. “If we
didn’t have that, I’d be guessing, but you could probably
treble those times, if not more in some cases.”
The multi task machine is a current pre-occupation,
but it’s part of the ongoing Oxford Engineering story. Jon
Raimbach is just as excited about the useful role that he sees for
EdgeCAM in helping the new Estonian facility become as effective
as that in Oxfordshire — and, perhaps, in other new phases
and developments as yet unknown.
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