5-axis laser cuts costs

Kryton Engineered Metals, a precision custom fabricator that specializes in the manufacture of concentric parts, has embraced laser technology. Established in 1981, the company has steadily grown into a high-tech contract manufacturer serving a wide range of industries including industrial air handling, lighting, medical, communications, automotive, and food and chemical equipment.

Kryton’s new 110,000ft² facility contains high tech tools including CNC metal spinning equipment; 3-axis, linear-drive, laser-cutting machines; robotic manufacturing cells; and press equipment. The most recent acquisition is the Rofin-Sinar Inc. UW505 2,000W, 5-axis fiber laser work station for cutting of three-dimensional (3D) parts. Kryton management recognizes that employing advanced manufacturing technology increases productivity, reduces costs, improves quality, and enables the company to respond faster to customer needs.

For the past few years, Kryton has cut sheet and plate materials with a Cincinnati CL707 powered by a Rofin DC035 CO₂ laser. When Rofin consulted with Kryton to modify the UW505 work station, Kryton embraced the opportunity improve 3D parts processing.
 

Kryton processes

Most parts that Kryton processes result from metal spinning, stamping, or deep drawing. The majority are produced in-house, but Kryton also provides contract services for companies that require secondary processing of their 3D parts.

Kryton performs metal spinning on eight CNC machines. A disk of metal is rotated at high speed while a forming tool applies force to the disk. Starting at the center, the tool slowly moves toward the disk’s circumference. By repeating this process, the metal is shaped to conform to a mandrel that is machined to the exact shape and dimensions of the desired part. During the spinning process, the metal takes the shape of the mandrel. The process resembles clay forming on a potter’s wheel.

Kryton also specializes in deep-draw forming and hydro-forming, processes in which the metal is shaped by compressing it within tooling or dies. Depending on the material and thickness, as well as the size and shape of the tooling, sufficient tonnage is required to perform the operation.

Since deep drawing requires the extreme stretching or drawing of the metal, deep-draw dies incorporate multiple stages of metal forming. This allows the metal to be formed in steps, so the drawing process is completed gradually, preventing tearing of the metal. Most deep-draw applications require secondary processing to cut out holes, slots, and flanges, because it is difficult, if not impossible, to incorporate these functions into the deep-draw dies.
 

Part challenges

Another challenge: Kryton processes a wide range of materials including steel, stainless steel, aluminum, copper, brass, and other specialty alloys. Raw material thicknesses range from 0.010" up to 0.500" and part diameters from 3" to 120". Most customer parts mandate dimensional and hole accuracies of ±0.010" or greater; however, some jobs require more than 50% tighter tolerances. Lot sizes are generally small to medium volumes, thereby requiring fast setup and changeover capability.

Since each 3D part represents a costly investment of materials, labor, and equipment burden rates, it is critical that the secondary processing is achieved without deformation of the part that would result in scrapped parts. Therefore, the cutting of holes, slots, and flanges requires accuracy and edge quality while maintaining the part shape integrity.

Most of Kryton’s typical parts are concentric because they are produced on CNC metal spinning lathes, formed in stamping dies, or created with deep-draw tooling. During processing of the material, the original material thickness can be reduced dramatically as the metal is stretched and formed.

Kryton’s challenge in processing the different 3D parts: efficiently and accurately position the part; then perform a precision, high-quality cut in a thin-walled metal alloy without deforming the edge or contour of the 3D surface.

The answer usually involves several complex steps:

• Make a fixture that conforms to the part geometry.
• Secure the part in a fixture that guarantees repeatable positioning.
• Accurately locate position of holes, cutouts, and flanges according to the 3D part print.
• Prepare and use a machine tool, die, punch, drill, saw, or hand tool to process the part.
• Process the part without deformation.
• De-burr or rework to insure high-quality edge condition and contour.
• Repeat the process when customers order more parts.
• Modify previous steps when design changes occur.

It is a labor-intensive and costly process. More importantly, each step adds handling to manufacturing time, limiting production throughput. The design, construction, and inventory of fixtures and dies also contributed to the manufacturing costs and burden rates.

Better solutions

Kryton addressed the processing challenges by developing part fixtures, custom die punches, and drilling fixtures. CNC lathes and machining equipment represented additional solutions. Often, manual operations using hand tools were employed to solve hard-to-access material removal or to perform de-burring. Frequently, complex parts required multiple setups and secondary processing such as drilling, die punching, flange trimming, and de-burring.

As an alternative to in-house secondary processing of 3D parts, Kryton outsourced some of the work to a local custom fabricator, adding costs and creating lead times.

After completing one year of operation including the learning curve, Kryton summarized the benefits of the Rofin UW505 fiber laser work station:

• Processing flexibility
• Multiple processing steps reduced to one laser-cutting step
• Efficient fixture generation reduced tooling production costs and expenses
• Eliminated re-work for many jobs
• Better part accuracy and repeatability on all parts
• Operator safety enhanced by reducing part handling and hazards
• Outsourcing dramatically reduced for challenging parts

The addition of 5-axis laser processing with the UW505 has dramatically improved the secondary processing of Kryton’s 3D parts. With the ROI and projected payback estimated to be approximately 1.5 years before tax incentives and depreciation considerations, the investment in laser technology has proven to be a good one.

Rofin-Sinar Inc.
www.rofin-inc.com
IMTS 2014 booth #N-6613

Kryton Engineered Metals
www.krytonmetals.com