Houston facility Machine
shops go deep
Shef eld-based Shepcote Engineering,
a manufacturer that specialises in
hydraulic cylinder manufacture, has
recently delivered another large unit to
Shef eld Forgemasters. This time around,
the cylinder was an all-stainless steel affair.
In desperate need of a replacement for
its press shop tool change cylinder, Shef eld
Forgemasters approached Shepcote, which
reports that “the cylinder was no lightweight
or easy job”. Measuring 590 mm in the bore
and over 7.6 m in length, the cylinder is
capable of producing 425 tonnes of force
and features double cushioning.
Shepcote Engineering says that it can
offer one of the UK’s largest in-house
DEEP HOLE DRILLING IN IT FOR THE LONG HAUL
machining capacities dedicated to hydraulic
cylinder manufacture. As part of this
provision, the company can deep hole bore
up to 1.2 m diameter by 12 m depth, and
hone cylinder bores up to 1.6 m internal
diameter by 32 m depth. Among the
machines in use is a Gehring (https://is.gd/
yigeci) deep hole borer with 11 m between
centres and a boring capacity up to 1,168
mm diameter.
Further south, at the Chessington facility
of Mollart (https://is.gd/aqugad), a major
contract has been secured that involves the
deep hole drilling of a defence sector
component that was rst manufactured over
25 years ago.
One of the Unisig
machines at Ryerson’s
Using the company’s own, recently
commissioned HD1 deep hole BTA machine,
Mollart was able win the contract ahead of
its competitors. According to the company,
this success was due to the support from its
in-house tooling partner Botek, which, in
collaboration with Mollart’s subcontract
team, came up with a modern and ef cient
solution to a very old machining/tooling
challenge.
In summary, Mollart has to drill 97 mm
diameter bores through 600 mm deep
components with an irregular external
pro le. The special forged material is
extremely challenging to procure, so there is
no allowance for scrapped parts.
A Botek type 42 drilling head that
employed special coated inserts provided
the tooling solution, while Mollart designed
and manufactured both the bushing
technology and dedicated workholding.
Steed Webzell reports on recent
deep hole drilling projects
for subcontractors, as well
as the initiative of a product
manufacturer to bring this niche
process in house
Small drills at up to 40xD
Available in the UK from Floyd Automatic Tooling (https://is.gd/
oyimin), the latest addition to the CrazyDrill range from Mikron Tool
will be introduced at the EMO 2019 exhibition (Hanover, 16-21
September – see p14 for a detailed preview). In Hall 3 on Stand
H11, the characteristics of the CrazyDrill Cool SST-Inox will be
demonstrated for show visitors to take on board.
The CrazyDrill Cool SST-Inox incorporates internal coolant ducts
and a special geometry and coating technology for the machining
of stainless steels, nickel-based superalloys and CrCo alloys.
Through-coolant drills in six different working lengths are available:
6xD, 10xD, 15xD, 20xD, 30xD and 40xD. For machining holes
between 1 and 2 mm diameter, the maximum depth available is
20xD. From 2 to 6 mm diameter, the entire range can be offered.
Although drills with spiral coolant ducts are available already in
small diameter ranges, Mikron Tool says that many get into
trouble with tough, elastic materials, or with the poor heat
conductivity that is displayed by superalloys. Here, cooling through
‘classic’ round ducts is insuf cient, the company offers, even
when using coolant at high pressure. Premature edge chipping,
packing of chips and build-up of the utes are all symptoms that
prevent stable drilling.
Markus Schnyder, head of Mikron Tool International and one of
the initiators of the tool development, knows all about the
problems: “For many years, our customers have been reaching the
limits when drilling stainless steel. The process was not stable,
and it was too slow and expensive, so we wanted to nd a
solution. The development took us several years and we’ve
depended on close co-operation with our partners, leading to the
use of the optimum blank material and a truly ef cient coating.”
Performance and process stability are mainly provided through
cooling the tool via two spiral internal coolant ducts up to the drill
tip, the company advises.
www.machinery.co.uk @MachineryTweets September 2019 73
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