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AEROSPACE SUPPLEMENT
October 2020 | www.machinery.co.uk | MachineryMagazine | @MachineryTweets
MACHINING CASE STUDIES
38
Traub lathes demonstrate
challenging material
machining credentials
Scottish manufacturer serving the global aerospace
sector Martin Aerospace, Lanark, chose a German-built
Traub TNL32-9P for its latest investment in slidinghead
turning technology, then opted for yet more Traub
technology more recently.
Supplied by Kingsbury ( www.is.gd/cijilu ), sole agent
for the UK, Ireland and Middle East, the sliding-head
machine started producing aerospace components from
tough alloys 24/5 from the beginning of 2018. It has
been so successful at ful lling an ongoing contract for
producing aero engine components from titanium,
Inconel and stainless steel that the business had no
hesitation in returning to the same source for a xedhead
lathe, a Traub TNX65. Installed in July 2019, this
machine produces parts from Inconel and Nimonic for
the same customer.
Both have reduced multiple operations to one-hit
production, making it easier to hold the required
tolerances, which are generally to within
±0.01 mm, although one pin diameter has to be turned
on the sliding-head lathe to ±4 microns. At the same
time, process cycles have been slashed, by over 90% in
one case on the TNL32-9P and by typically 70% on the
TNX65, added to which handling time and work-inprogress
have been eliminated. Such signi cant savings
are partly a result of the ability on both machines to
have three tools in cut simultaneously, each having a
different feed rate for optimum metal removal.
Neil Lawson, operations director at Martin
Aerospace, explains: “In 2017, a customer increased
its annual requirement for ve different parts, with
quantities rising from a few hundred to 6,500 per part
number. We were making them on a variety of twinspindle
turn-mill centres of sliding- and xed-head
design.
“Such a sharp increase meant
investing in a new turning centre to
meet the demand and a sliding-head
lathe was appropriate, in view of the
shaft-type proportions. I went online to
review what was available for
machining our tough materials and
Traub kept appearing in searches,
often with reference to medical applications.”
In a demonstration, one two-operation cycle time of
6.5 minutes on the sliding-head machine was reduced
to a 1.2-minute single operation on the Traub, which is
the shortest cycle. In another case, a 55-minute threeoperation
process was cut to one 15-minute cycle,
which is now the longest. So compelling was the demo
that he ordered the machine on the same day and four
weeks later it was being commissioned on the shop oor
in Lanark. All ve parts are produced from bar to a
process capability of Cpk 1.67, underpinned by 100%
inspection, before they go for grinding and thread rolling.
Lawson con rms that over the life of a tool cutting edge
or insert, dimensions of features produced on the Traub
sliding-head lathe do not vary by even a micron.
For the xed-head machine, a borescope that also
saw volumes increased is made from an Inconel billet
63.5 mm in diameter, 70 mm long and weighing 2.7 kg
and previously took 147 minutes for the completion of
seven operations on horizontal and vertical machining
centres and lathes, during which the weight was
reduced to 0.7 kg. The cycle time was cut rst to
65 minutes in a single operation on a twin-spindle turnmill
centre already on the shop oor, on which it was
possible to have two tools in cut simultaneously, one
each deployed by the two tool carriers. The Traub TNX65
xed-head lathe performed the required work in one hit
in 25 minutes, a further cycle time reduction of more
than 60%.
Concludes Lawson: “Kingsbury supplied the
machines as turnkey packages, which our engineers
have tweaked on the shop oor to gain extra productivity
advantage.
“The supplier’s back-up has been excellent, including
when we telephone with a query, as has the training
provided for machine operation and programming using
Traub’s of ine CAM software.
At Martin
Aerospace,
two Traub
lathes have
tackled
increased
part volumes
in challenging
materials,
slashing
cycle times
signifi cantly
into the
bargain
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