Harold
Kerzner, an internationally recognized authority in project management
defines “Best Practices” “as those processes, procedures or practices
in which a company replicates a similar situation because it has proven
to be valuable or successful in the past, it will be assumed to be
successful again in the future.”
In reality best practice might better be explained as “repeated
applications” of the best practice in a similar project or business
context that we can define it as true Best Practice.
Below we will discuss how Best Practices apply to the advanced technology available in milling stud lines
Change Over
Most structural stud lines use a hydraulic flying punch press with an
air cylinder boost and die return system. This hydraulic punch press is
boosted to line speed using an air cylinder and then boosted back to
home position with the same air cylinder. This method often adds
unnecessary time, thus slowing the entire process. It is very difficult
to match the line speed of the material gauge with the air cylinder’s
boost requiring about 15 minutes for the operator to make the
adjustments, and then run a dozen or more parts just to test the line
before running at the desired top speed. Because this is such an
arduous series of tasks to accomplish accurately, it rarely provides the
desired result. Because of the repeated “tweaking” of the air pressure
setting on the air cylinder boost for each gauge or the line speed and
all the scrap it creates, most operators will not go to the trouble.
Instead, the operator typically establishes a compromised setting that
will work for each material thickness and line speed, ultimately
settling for a much slower line speed. In turn, this ‘compromise’ can
be inefficient and ultimately affect cost overruns. Cutting corners in
this way can have a drastic reduction in output.
Often
reducing an operations capable capacity by as much as 50%. This of
course can have a dramatic impact on not only the company’s potential
revenue, but also on its ability to meet customer demand.
Compressor-Free
The process described above requires an air cylinder boost and die
return system on a flying punch press. Because of advances in
technology, many manufacturers of studs require their lines be
compressor-free.
Running
a compressor on a continual basis to adequately operate a die return
system can be very costly. These compressors are often required to
actuate a large air cylinder at a cycle rate of one- per-second in order
to punch the knock-out holes along the stud, consuming an enormous
amount of energy during a single shift. Cost for operating this type of
large air compressor for this particular operation can run as high as
$75,000 per year. This is often a ‘hidden’ cost, one that is not
considered in the equation when designing a stud & track line.
However, some compressor-free technologies operate a rotary punch
system that consumes as little as 1 CPM, even at top speed. This
eliminates the need for a large, high-maintenance and energy consuming
air compressor.
Automating Part Selection & Throughput
Most traditional stud roll-forming lines are designed to require
manual change-over of parts. Though the machine manufacturer may
present it as ‘automated’, the extent of automation may be limited to
selecting the correct button to find the appropriate setting of the web
width, manually set the flange height, and then selecting another button
for the proper material thickness. The operator must then manually
adjust the entry guide, the straightening fixture and then the overbend
tooling. Each of these separate process are time consuming, labor
intensive and leave many opportunities for human error.
These
manual processes can be completely eliminated when using a fully
automated roll former. Some automated machines maintain a “Library” of
product parts, which can be automatically selected by an on-board
computer and set into operation by a 13-axis auto positioning control.
The operator simply selects a part from the product library on a touch
screen and one of 13 digitally-controlled settings will automatically
place the part for the specific operation.
Reduced Maintenance Costs & Downtime
As described above, traditional mills rely on flying punch presses
for the knock-out holes along the stud tracks. Flying punch presses are
appropriately named, because their operation is that of a fast moving
tool, thrust by the action of a hydraulic press. Because these
continually moving parts are literally ‘punching’ the holes through the
stud, the constant action on the tool, vibration on the equipment and
continual flexing of the hose, cause a huge strain on the equipment. As
the hoses rub against each other and the interior lining erodes due to
the internal fluid velocity, the typical result is tool breakage,
leaking hoses and valve failure. This type of system is in a continual
state of repair.
Total Cost of Ownership
Total Cost of Ownership (TCO), aka; life cycle cost analysis, is an
analysis meant to show the lifetime costs that come from certain large
scale assets. Ownership brings much more than purchase costs. It
includes costs for installing, deploying, operating, upgrading, and
maintaining the assets. For most operations, TCO analysis proves a
major difference between purchase price and total life time asset cost.
TCO analysis is used to determine the best methods of acquisition and
planning for a wide range of assets, including large capital equipment
such as stud mills. With major production equipment, like other
machinery assets, there can be significant maintenance or operating
costs during the service life. Total cost of ownership analysis is, and
should be, the primary focus of management when making decisions for
major equipment purchases. TCO is the focal point of:
- asset life cycle management
- budgeting and planning
- prioritizing capital acquisition proposals
- vendor selection
A company’s Total Cost of Ownership helps an organization understand
the “value” of the equipment, not just the “purchase price”.
The choices in selecting the best stud & track line are:
- Follow a thorough maintenance program that includes a daily operator
observation along with a six month or annual discrete program in which
the machine is taken out of service.
- Select an automated system that reduces operator interaction with
the machine, virtually eliminating frequent repairs. This automated
system also produces consistent and uniform parts that meet customer
specification.
If the company conducts a thorough Total Cost of Ownership analysis
prior to investing in a stud line, their clear choice will be to select
option #2.
To see a fully automated milling stud line in action, click
here.
See our B&K blog
A single mandrel uncoiler is a key component to an efficient system.
This type of design can handle up to six thousand pounds, while an
optional double mandrel unit allows operation from one side while coil
is loaded to the other. When it is time to switch sides, the reel is
simply rotated, threaded up and the system is ready to operate with the
second coil quickly in place.
adjustable
edge guide ensures proper alignment with the roll former to make
thread-up quick and easy when switching between profiles. In addition,
hardened upper rolls are individually adjustable to provide the exact
roll pressure needed while keeping the rolls parallel. The following
station then punches holes and shears the strip to the precise length
prior to the roll former.
punching” option, the rotary can simply roll off
