M A I N T E N A N C E
AS GOOD
AS NEW
GENERAL OVERHAUL OF TUBE BENDING MACHINES
To buy new or second-hand? When purchasing a car, consumers tend to make their decision based largely
on price. And if you happen to have a well-maintained car in the garage whose only downside is a stuttering
engine, then a trip to the workshop is usually the first port of call. A similar approach can be applied to tube
bending machines. Many companies have been reliably using the high-investment machines for decades. But
at some stage the technology might reach its limits. In some instances, a general overhaul can be an alternative
to buying a new machine. In which cases does this make sense and in which not? The tube bending machine
manufacturer Schwarze-Robitec provides an overview.
From the automotive industry
to shipbuilding to power plant
or boiler construction: In many
industries, tube bending machines
are an indispensable part of the
manufacturing process. They have to bend tubes
precisely and quickly. Although a high-quality
machine is a major investment, the costs are
rapidly amortized. In addition, good machines are
often in use for decades. Once the technology
reaches its limits, many users decide in favour of a
general overhaul of their machine.
OLD MACHINE FRAME, NEW
COMPONENTS
One of the leading international experts in the
sector of tube bending machines is Germanybased
company Schwarze-Robitec. When a
client orders a general overhaul of one of their
machines at Schwarze-Robitec, it is usually
back in operation six months later. However,
clients only have to do without their machines
for around eight weeks. Prior to the overhaul the
tube bending machine manufacturer procures
the necessary materials and purchased parts,
and manufactures the components. Only then the
machine is delivered and fully disassembled into
its individual parts. Schwarze-Robitec sandblasts
all welding components and the entire machine
frame in order to remove the old paintwork. All
welding seams are also checked. So whilst the
machine frame and the welding components are
re-used, all hydraulic and electrical installations
are replaced, including hydraulic piping, cables,
control cabinet, control technology and control
panel. In addition, the entire machine safety
system, including the CE components, for
instance, is newly installed during a general
overhaul. This is due to the fact that statutory
safety regulations have usually changed since
the machine was first put into operation. This
is ultimately followed by the assembly of the
overhauled machine – including the preliminary
acceptance test at Schwarze-Robitec’s site in
Cologne and the machine being put into operation
at the desired location – as is the case with a new
machine. A 12-month warranty period is offered.
General overhauls are usually ordered by clients.
However, in some instances the manufacturer
sells a machine that has undergone a general
overhaul. This can be a particularly interesting
prospect for buyers if the machine configuration
is ideally suited to their performance requirements
and they are working on a tight budget. Since
expensive parts such as the machine frame and
welding components are re-used, an overhauled
machine is roughly one-third cheaper than a new
machine. And yet the buyer receives a product
which is as good as new with state-of-the-art
technology.
KEEPING AN EYE ON A MACHINE'S
OVERALL CONDITION
If a car suddenly starts to stutter and breaks down
on the road, this doesn't mean that it is a complete
write-off. Perhaps it only requires a new oil filter,
new spark plugs or maybe even a new engine.
For tube bending machines, this is equivalent
to a component overhaul. If, for example, a new
pressure die assembly, a new swing arm or a
new bending head is installed, it is possible to
get the machine back up and running again.
However, it is necessary to keep an eye on the
overall condition of the machine. For instance,
for Schwarze-Robitec’s control systems from
previous generations prior to the year 2000,
there is often only a limited availability of spare
parts and upgrades are no longer possible. If
such machines are mechanically refurbished,
the control technology will still pose a risk
of failure – a general overhaul including a
replacement of the control system is therefore
a more sensible option. But should a client's
production requirements change fundamentally,
then a new machine is in order. Just as with a car,
installing a new engine is not worthwhile if this is
then shortly followed by a gearbox failure – or if
the owner now needs a van instead of a station
wagon.
Tube bending machines are also similar to cars
in terms of the intervals between necessary
maintenance work: The car of an everyday
commuter – equivalent to a machine working
at high capacity in 3-shift operation – will be
in for its next inspection quicker than that of
the casual weekend driver. The frequency
with which tube bending machines require
maintenance work varies depending on their
utilization, workload and regular maintenance.
It is therefore the combination of many factors
that determines whether a general overhaul is a
reasonable option: the time, the condition of the
machine and the performance requirements in
production.
22 February 2020