process development knowledge for its successful
implementation. Turner again: “The machine is sort of
plug-and-play, although temperature and humidity will
affect it, as will how the part is orientated in the
machine. The process is isotropic equal strength in all
directions, but there is heat in the build that will impact
parts, depending on orientation. All this will determine
how a part comes out. You have to understand the
process to know how to set up parts for build, how you
are going to inspect them, how you will measure process
control. HP supplies the machine and trains you, but
you’ve got to have some key staff to nail the process
after that.”
PRODUCTIONISED PROCESS
The company has so-called ‘controlled builds’, standard
nests of parts, that support this approach and allow SPC
data to be gathered. It is possible to manufacture good
parts in isolation of this, but the company doesn’t get
the volume of data to support SPC. The creation of a
variety of standardised packs is the aim. “Getting the
ultimate production process while benefiting from 3D
printing’s flexibilities is what we are about,” says Turner.
And this approach to AM is not being applied by anybody
else, it is claimed. Undoubtedly why HP invites Turner to
speak on this topic at various global events.
And this also explains why the company is not too
concerned about copy-cats. It will cost the best part of
£500,000 to get into the game and companies would
have to be running close to capacity, 24/7 to make that
viable. Having its own product that will remain in demand
for years yet, offered through an established sales
channel, means Bowman is in that position, with this
providing the ‘base load’ on which it can build its
subcontract AM service. So, while capacity utilisation has
to be around 80% to make the current operation viable,
with more machines that figure drops as the linked costs
do not rise in linear fashion. With three machines, 45%
capacity utilisation would be okay, for example.
Apart from that, competing AM bureaux are unlikely to
be able to develop production-related quality control,
inspection regimes, statistical process control,
traceability, verification and proof of repeatability, says
Ashby. Every Bowman Additive bearing production part
has a serial number on it, providing full traceability down
to temperature, humidity and position in the nest,
for example.
Rock drill bearings/press tool linear sleeve ball
bearings that traditionally use machined phosphor bronze
cages are a further bearing product target, with cost
savings “humungous”, Ashby stresses, alongside, once
again, large performance benefits. On test, it is just one
of a number of applications, both internal and external,
that Bowman Additive has in mind, underpinned by its
capable, traceable AM production processes. ■
LEAD FEATURE ADDING VALUE WITH ADDITIVE MANUFACTURING
Arkema and Evonik, for example. The same for the ‘inks’
used in the curing process (see box, below).
In addition to the 3D printer, the company spent a
further £180,000 on surface finishing machines, Medit
Solutionix CS2 3D scanning equipment (www.solutionix.
com), Guyson Formula 1400 manual blaster (https://
is.gd/yapahe) and Dyemansion Powershot S polishing
equipment (Europac, https://is.gd/fodani), so as to deliver
high quality and repeatable parts. Bearings are critical
components, after all.
Now, while 3D printing doesn’t require a high skill set
to run a machine, it does, just as is the case with
achieving capable machining processes, require a level of
A high value
speaker system
part produced
for an external
customer, with
such an
economical
service resting
on the ‘base
load’ of
Bowman’s own
parts
manufacture
HP Jet Fusion 4200 – the process
Having a working envelope of 380 by 284 by 380 mm (L, W, H), the machine
spreads a layer of material 80 microns thick in one pass of the whole
envelope, lays down ‘ink’ for part details falling within that layer in a second
pass, then fuses those inked details in a further pass, using heat, achieving
a build speed of up to 4,115 cm³/hr. Part complexity comes for free and it’s
the same cost for producing one part as for producing several hundred of the
same part in the working envelope. There are no support structures, the
build unit is removed from the machine and unfused material removed. This
can take place in parallel with processing a second build unit. Watch the HP
Jet Fusion 4200 video: https://is.gd/ukopun.
12 October 2019 www.machinery.co.uk @MachineryTweets
/(www.solutionix
/fodani)
/ukopun
/www.machinery.co.uk