The Pipe Diameter Correlation for Roller Bed vs. Chucking
Written by Brett Fornelli
VERNON TOOL® pipe profilers are manufactured as both roller bed and chucking style machines. The advantages of each design are specifically engineered for the industry and pipe size that will yield the highest productivity with the smallest material handling labor cost. Through five decades of experience, it has emerged that roller beds are better for cutting heavier, larger diameter pipe, while chucking systems are better for lighter, smaller diameter pipe. Choosing the right pipe-cutting system design for the desired application will have a long-term effect on your bottom line profit.
Vernon Tool’s machines with roller beds and conveyors are the basis for our continuing success in the world of large diameter pipe cutting. It began with the original pantograph machine, and carries on today with our highest end pipe profiling machine line, the Master Pipe Machine (MPM) series. This product line is known to regularly last 20+ years under daily use, with some machines still operating after 50 years. The MPM pipe-cutting machine not only outlasts its competition, but also simplifies the loading and unloading processes.
The Vernon Tool roller bed system allows a single operator to load pipe from storage racks onto the entrance conveyor, which then advances it onto the roller bed. That same operator can cut the pipe on the roller bed to the programmed specifications, and then convey it for discharging onto the finished-piece racks. This operator can convert a fully-loaded rack of raw materials into finished pieces without the use of an overhead crane or additional personnel to assist in handling the material. The roller beds automate the flow of materials to a level that cannot be achieved by competing systems.
In addition to simpler material handling, the roller bed system allows the operator to cut anywhere along the length of the bed while the system is providing full support of the pipe. Chucking machines that cut pipe larger than a foot in diameter require multiple support adjustments for each pipe. Each of these adjustments require an extra step in the process and not only increase labor costs, but also bog down production. The roller bed system takes out these extra steps, and allow pipe to be taken through the entire process while maintaining full support.
The roller bed system also provides a drop area for the operator to collect short finished pieces or the waste end of the first cut. Because the profiler carriage extends several feet beyond the machine bed, it allows ample room for a waste bin or finished-piece tray. Remnants are also easily conveyed back onto the raw materials rack if additional cuts are needed. This unique feature of the roller bed system improves material handling and the processing of finished parts.
The production of Vernon Tool pipe cutters involves calibration of our roller bed systems to within very tight tolerances. Every machine undergoes an x-axis drive shaft alignment with laser sighting to align the two drive shafts with each other. An aligned x-axis prevents the pipe from advancing down the y-axis in a screw-like fashion—something known in the industry as “pipe walk.” This step is performed with every roller bed system that we manufacture and calibrates the machine to ensure that pipes shift no more than 1/32” in 25 revolutions, a statistically insignificant amount.
The roller bed system also overcomes additional obstacles in making an accurate cut. Pipes are naturally never straight or true, and often fluctuate greatly with increasing length and pipe diameter. Our roller bed system overcomes this with its ability to self-center. A pipe may raise and lower slightly in the bed if there is a bow or weld seam, but this is always compensated for with pipe sensors to adjust the torch to the correct pipe height. With large chucking machines, there may be a bow over the length of a long pipe, and the centerline of the pipe can differ several inches from the chucked end. The amplification of chuck misalignment can lead to costly rework and add substantially to both production time and overall cost.
While large pipe is better suited for a roller bed machine, chucking machines have their place. Lightweight or smaller diameter pipe and tube require less material handling steps, and are easier to maneuver along the length of the machine. Lincoln Electric Cutting Systems, maker of Vernon Tool pipe cutters, identifies these chucking benefits, and offers a machine with a chucking system: the MASTERPIPE® Compact Profiler. This machine was specifically engineered to handle smaller pipes and tubes that range from 1-8 inches in outside diameter. Vernon Tool engineers have found that the chucking system is the most effective within this scope of pipe and tube sizes.
A smaller machine footprint is an added benefit of using chucking machines, as there is less need for entrance and discharge conveyors. Smaller diameter pipes are generally easier to handle, so operators have more control in maneuvering and placing pipes within the chucking jaw. Pipe racks can be stacked vertically alongside the machine and easily accessed. Control over the pipe has a direct correlation with its size and weight; the smaller the pipe, the easier it is to control.
There are machines that currently use a combination of the chucking and roller bed systems, but the major cost that is compounded by coupling the systems outweighs any minor benefits. The most significant gain of a chucking machine, floor space, is lost when using a roller bed and chucking system combination.
Recognizing the correlation between pipe diameters and machine bed types will greatly optimize your production process and bottom line profit. Having the correct system can accelerate production by reducing material handling times and the labor involved, which represents a significant line item cost. These two factors generally represent 80% of the time involved in pipe cutting, so it is critical to load, set-up, and unload the pipe as efficiently as possible.
Roller beds are recognized as the most efficient and cost effective system for larger diameter pipe because they significantly boost efficiency in handling pipes larger than twelve inches in diameter. On the other hand, chucking machines take up the smaller sized pipe cutting market by capitalizing on the ease of handling smaller material. This correlation between pipe diameter and appropriate machine design is clearly recognized in the Vernon Tool line of pipe profiling and cutting machines.