machining
current 80,000 components a month schedule – and
apart from replenishing the bar feed and strictly timed
tool changes – never stops.
‘We were sure the new machine would be so much
more productive on this component than our existing
three Citizen L32 and two L20 machines due to its
shorter axis strokes,’ says Julie Malin.
‘Even if we had failed to win the
contract, we were confident we could
easily put other work on the machine
and be very competitive when quoting
for parts up to 20mm diameter.’
One of the major attractions to the
Malins for the seven-axis Citizen A20-
VII machine was its availability as a
ready-to-run package with Iemca
barfeed, workpiece conveyor, delivery,
commissioning and training. The
machine can carry up to 21 tools and
with its X-2 axis on the sub-spindle
and back tool post enables two-tool
simultaneous cutting on the front and
reverse of the component. There are
four driven tool positions and full Caxis
capability is available on each
spindle. Also part of the A series from
Citizen is the recently introduced
A32-VII. This heavy duty machine
takes the philosophy of the A20 into
the larger material size category of 32mm diameter
enabling parts up to 320mm long to be machined in a
single chucking. The first two A32-VII machines have
been installed by subcontract machinist, Unicut
Precision of Welwyn Garden City.
Swiss tradition
Swiss sliding head specialist Tornos is also targeting the
entry level market with its new Delta range. Born of the
recent agreement reached with Tsugami, the Delta series
comprises nine models from 12 to 20mm diameter
capacity in three, four and five axes, with the Swiss
manufacturer now delivering an altogether simpler
range of machining solutions. ‘With Delta, we will be
offering entry level products,’ confirms Alain
Augsburger, Tornos’ Delta line product manager. ‘It
comes from constant requests to provide simple machines
that enable customers to create relatively straightforward
workpieces in a cost effective manner.’ Notwithstanding
the new agreement with Tsugami, the new Delta
machines are considered ‘true Tornos machines’ that
happen to be manufactured by Tsugami. Essentially,
Tornos is working with Tsugami as a manufacturing
partner to produce Delta machines on its behalf.
German turning specialist Gildemeister is another
machine tool vendor now offering entry level machines
in its series of CNC sliding head turn-mill centres. The
5-axis Speed 12-5 linear and 12-7 linear also incorporate
Y-axis cross feed into the seven-axis specification. Each
has a bar capacity of 15mm diameter and the Z-axis
longitudinal travel is 120mm. Central to the Speed 12
machine design is the ease of access to the working area
for setting and the configuration of an independent
linear driven slide able to accelerate at 10m/sec 2. With
such a high acceleration capability, non-productive
positioning time is minimised in reaching the rapid
Axis arrangement of
DMG Speed 12-5 linear
Dave and Julie Malin’s
DMJ Precision invested
in a new Citizen A20 VII
after spotting and
evaluating the machine at
MACH2008.
www.stargb.net
www.citizenmachinery.co.uk
www.tornos.com
www.gildemeister.com
www.dugard.com
www.axestatus.com
traverse rate of 40m/min to service both main and
counter spindles.
In keeping with the five versions in the Speed range,
both entry level machines are available with options for
deep-hole drilling and the latest patented thread
whirling for spiral or course threading applications
such as those required on bone
screws for the medical sector. Not
only does the new thread whirling
device deliver high orders of
precision and surface quality in a
single pass, it also enables increases
in tool life up to 35% to be achieved.
Import export
The development of entry level
machines by the likes of Star, Citizen,
Tornos and Gildemeister is also a
response to the increasing number of
competitively priced sliding head
automatic lathes that are being
imported from the Far East. Such
machines, although sporting
attractive price tags, are becoming
increasingly well specified, and as a
result, are gaining widespread
popularity in Western manufacturing
economies. The Dugard Eagle 32
sliding headstock CNC lathe is a
prime example of a well built machine growing in
reputation. The 7-axis machine features a sub-spindle
and Y-axis cross feed capability. It is also available as a
fully integrated ready to run package comprising 3m
magazine barfeed, parts catcher and chip conveyor.
According to Dugard, the Eagle 32 is said to require
around half the investment to purchase than is
normally expected for a machine of its class and quality
of build. It uses a cast iron base and headstock to
provide high stability and incorporates a servo-driven
counter balanced sliding headstock design carried on
precision linear guideways. As a result, milling and
turning can be performed using full C-axis for
contouring, as well as integrated milling and drilling
operations within the ready to run specification.
Up to six 12mm shank or, as an option, five larger
16mm shank tools are carried on an over-the-spindle
tool slide. However, the addition of an axial milling
attachment provides five stationary and three driven
tool positions available for end working. The provision
of a radial milling attachment driven by a 0.5kW Y-axis
motor means that a further four driven tool positions
are available for machining external features on a
component. Each of the driven tool positions are fully
programmable up to 6,000revs/min and the machine is
able to perform polygon turning cycles.
Elsewhere, another import machine gaining notoriety is
the Diamond 20 series Swiss-type CNC sliding head lathe
from Polygim, which is represented in the UK by Axe &
Status. Various tool combinations and options are available
including a back-spindle for front/rear simultaneous
machining and 5˚ spindle indexing function.
Entry level machines have always offered cost effective
means of attaining well specified technology at a
reasonable price. Today, in a world of struggling financial
markets, this arrangement holds even greater resonance.
52 MWP may 2009
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