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.
About the Author
B&K is a member of the Formtek Group. Formtek is a group of long-established companies, each with a well-known name and a history of providing innovative, reliable equipment to the metal forming and metal processing industries. As a single source provider, Formtek continues to supply its customers with the highest quality equipment, parts and service available in the industries it serves.
References: