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Home / 5-Axis Laser Cuts Costs at Kryton

5-Axis Laser Cuts Costs at Kryton

This technical review examines how 5-axis laser processing dramatically improved the secondary processing of 3D parts at this high tech job shop.

Posted: February 2, 2015

The horizontal rotary table on the Rofin UW505 2,000 Watt 5-Axis Fiber Laser Work Station at Kryton facilitates easy mounting and centering of part fixtures in the workstation. Rotating the part to locate hole cutting positions or to perform flange cuts greatly enhances the efficiency and accuracy of the system. The vertical rotary drive of the laser cutting head represents the 5th axis and allows the cutting head to maintain perpendicularity of the laser beam to the material’s surface.
Figure 1. The new 110,000+ sq ft Kryton facility contains a variety of high tech equipment, including CNC metal spinning equipment, 3-axis linear drive laser cutting machines, robotic manufacturing cells and press equipment.
Figure 2. 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 towards the disk’s circumference. By repeating this step, the metal is shaped to conform to a mandrel that is machined to exact the shape and dimensions of the desired part. During the spinning process, the metal takes the shape of the mandrel. This process resembles the appearance of clay forming on a potter’s wheel. (Illustration courtesy of CustomPartNet)
Figure 2-1. 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 towards the disk’s circumference. By repeating this step, the metal is shaped to conform to a mandrel that is machined to exact the shape and dimensions of the desired part. During the spinning process, the metal takes the shape of the mandrel. This process resembles the appearance of clay forming on a potter’s wheel. 
Figure 2-2. 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 towards the disk’s circumference. By repeating this step, the metal is shaped to conform to a mandrel that is machined to exact the shape and dimensions of the desired part. During the spinning process, the metal takes the shape of the mandrel. This process resembles the appearance of clay forming on a potter’s wheel. 
Figure 2-3. 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 towards the disk’s circumference. By repeating this step, the metal is shaped to conform to a mandrel that is machined to exact the shape and dimensions of the desired part. During the spinning process, the metal takes the shape of the mandrel. This process resembles the appearance of clay forming on a potter’s wheel. 
Figure 2-4. 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 towards the disk’s circumference. By repeating this step, the metal is shaped to conform to a mandrel that is machined to exact the shape and dimensions of the desired part. During the spinning process, the metal takes the shape of the mandrel. This process resembles the appearance of clay forming on a potter’s wheel. 
Figure 3-1. Deep draw forming (shown here) and hydroforming shapes metal 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 either operation. Since deep drawing requires extreme stretching or drawing of the metal, deep draw dies incorporate multiple stages that form the metal in steps so the drawing process is completed gradually to prevent the 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. (first view)
Figure 3-2. Deep draw forming (shown here) and hydroforming shapes metal 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 either operation. Since deep drawing requires extreme stretching or drawing of the metal, deep draw dies incorporate multiple stages that form the metal in steps so the drawing process is completed gradually to prevent the 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. (second view)
Figure 3-3. Deep draw forming and hydroforming (shown here) shapes metal 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 either operation. Since deep drawing requires extreme stretching or drawing of the metal, deep draw dies incorporate multiple stages that form the metal in steps so the drawing process is completed gradually to prevent the 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. (third view)
Figure 3-4. Deep draw forming and hydroforming (shown here) shapes metal 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 either operation. Since deep drawing requires extreme stretching or drawing of the metal, deep draw dies incorporate multiple stages that form the metal in steps so the drawing process is completed gradually to prevent the 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. (fourth view)
Figure 4-1. Custom fixtures facilitate accurate drilling and punching operations, while insuring that the 3D part contour is not distorted. (first view)
Figure 4-2. Custom fixtures facilitate accurate drilling and punching operations, while insuring that the 3D part contour is not distorted. (second view)
Figure 5. These are the possible CNC solutions that Kryton examined. Each has pros and cons, but all are currently used in manufacturing plants to perform cutting operations on 3D parts. Some of these may be required for specific part applications, but this chart assumes that the CNC work station needs to provide the best solution for the Kryton job shop environment.
Figure 6. The UW505 installation and the design criteria for Kryton create a compact foot print, a Class I Enclosure for safety, fork truck mobile frame construction and quick disconnect features for ancillary components, including the laser, chiller and controls. These features provided easy installation and startup, plus mobility in the event of plant reorganization.
Figure 7. The stress-relieved, welded steel construction of the UW505 is precisely machined to accept the linear drives and rotary table, as well as adjustable mounting feet and the removable 2D cutting table with scrap draw and fume box assembly. The heavy duty steel frame requires no special foundation and allows the UW505 to be moved easily with a fork lift. Anorad linear drives are employed for 1,600 ipm high speed positioning of the X-, Y- and Z-axis at +.001 in accuracy, +.0005 in repeatability, with inboard-outboard linear guiding and wear-free performance. Rotary drives from IntelLiDrives, Inc. (Philadelphia, PA) complete the 5-axis capability.
Figure 8. The horizontal rotary table on the UW505 facilitates easy mounting and centering of part fixtures in the workstation. Rotating the part to locate hole cutting positions or to perform flange cuts greatly enhances the efficiency and accuracy of the system. The vertical rotary drive of the laser cutting head represents the 5th axis and allows the cutting head to maintain perpendicularity of the laser beam to the material’s surface.
Figure 9. The FL020 2000 watt was selected for this UW505 machine because it can effectively process all the materials and thicknesses. This schematic represents the unique fiber laser design. Instead of hundreds of single, hard-spliced diode emitters, the single diode emitters are packaged into fiber coupled modules to simplify the components and facilitate easy serviceability.
Figure 10-1. Here are the key components of the FL020 2000 watt fiber laser, Optoskand 100 micron fiber optic beam delivery and LaserMech Fibercut Capacitance Sensing Cutting Head with 125 mm focus lens and 250 psi maximum assist gas pressure. The fiber laser system provides the ability to easily process all alloy materials and thicknesses that are generally encountered in this job shop. The 10 mm focusing lens adjustment and precision capacitance sensing standoff settings insure that all materials can be processed with high quality, dross-free kerf cuts of .005 in width. (second view)
Figure 10-2. Here are the key components of the FL020 2000 watt fiber laser, Optoskand 100 micron fiber optic beam delivery and LaserMech Fibercut Capacitance Sensing Cutting Head with 125 mm focus lens and 250 psi maximum assist gas pressure. The fiber laser system provides the ability to easily process all alloy materials and thicknesses that are generally encountered in this job shop. The 10 mm focusing lens adjustment and precision capacitance sensing standoff settings insure that all materials can be processed with high quality, dross-free kerf cuts of .005 in width. (first view)
Figure 11. CENIT software imports the 3D part model creating the fixture and CAD/CAM program. A unique feature of this software is its ability to easily create the part fixture from the 3D model. The part fixture, having intersecting blades that conform perfectly to the part shape, is center-mounted to the rotary table because the software is configured to reference the absolute point on the rotary table. Using this input and the part contour, the software prepares a 2D nest program of the fixture base and intersecting blades. The nest is laser cut out of 11 ga steel and assembled using precision tab and slot features generated by the software.
Figure 12-1. These 11 ga steel part fixtures were generated by CENIT software, cut on a laser and assembled to process parts in the UW505. The software can also create UW505 machine simulations from the 3D part models for time studies that also predict potential head crash interferences. (first view)
Figure 12-2. These 11 ga steel part fixtures were generated by CENIT software, cut on a laser and assembled to process parts in the UW505. The software can also create UW505 machine simulations from the 3D part models for time studies that also predict potential head crash interferences. (second view)
Figure 13-1. Part 1: This 12 ga steel can was one of three parts that were selected to conduct an analysis of the UW505 processing benefits and ROI. Besides representing different physical characteristics, these parts represent secondary features that required unique processing steps prior to the UW505.
Figure 13-2. Part 2: This .120 in stainless tank was one of three parts that were selected to conduct an analysis of the UW505 processing benefits and ROI. Besides representing different physical characteristics, these parts represent secondary features that required unique processing steps prior to the UW505.
Figure 13-3. Part 3: This .090 in aluminum dish was one of three parts that were selected to conduct an analysis of the UW505 processing benefits and ROI. Besides representing different physical characteristics, these parts represent secondary features that required unique processing steps prior to the UW505.
Figure 14. Processing 100 pieces of Part One required 24.81 hours of multiple steps.
Figure 15. Outsourcing Part Two was time consuming and costly, with a three week lead time.
Figure 16. Processing 100 pieces of Part Three required a slow drilling process with a fixture.
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Kryton Engineered Metals Inc. (Cedar, Falls, IA), a precision custom fabricator that specializes in the manufacture of concentric parts, has embraced the benefits of 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 suppliers, food and chemical equipment manufacturers, as well as niche markets.

Management recognizes that employing advanced manufacturing technology increases productivity, reduces costs and improves quality while responding faster to customer needs. Their most recent acquisition is the UW505 2,000 Watt 5-Axis Fiber Laser Work Station from Rofin-Sinar, Inc. (Plymouth, MI) for the cutting of 3D parts.

Most parts here are produced in-house from either metal spinning, stamping or deep drawing, though the job shop also provides contract services for companies that require secondary processing of their 3D parts. For the past few years they have cut sheet and plate materials with a Cincinnati CL707 powered by a Rofin DC035 CO2 laser. When Rofin consulted with management to modify the UW505 5-Axis Fiber Laser Work Station, the company embraced the opportunity improve how they process their 3D parts.

Metal spinning parts here represents a unique type of 3D fabrication because of the method employed to create the part and the challenge of cutting secondary features. Figure 2 depicts the metal spinning process that is performed on eight CNC machines.

Deep draw and hydro-formed parts represent another challenging 3D fabrication for Kryton, as shown in Figure 3. Another challenge facing the shop is the wide range of materials being handled, including steel, stainless steel, aluminum, copper, brass and other specialty alloys. Raw material thickness ranges from .010 in up to .500 in and part diameters from 3 in to 120 in. Most parts mandate dimensional and hole accuracies of +.010 in or greater, but some jobs require over 50 percent tighter tolerances. Lot sizes are generally small to medium volumes that require fast setup and changeover capability.

Since each 3D part Kryton produces represents a hefty investment in material costs, labor and equipment burden rates, it is critical that secondary processing does not deform and scrap the part. Hole, slot and flange cutting requires accuracy and edge quality while maintaining the part shape integrity. Most parts are concentric because they are produced on CNC metal spinning lathes or formed in stamping dies or deep draw tooling. During the processing of the material, the original material thickness can be reduced dramatically as the metal is stretched and formed.

The question the job shop always had to answer in processing these different 3D parts was: How do we efficiently and accurately position the part and perform a precision, high quality cut in a thin-walled metal alloy without deforming the edge or contour of the three-dimensional surface? The answer usually involved several complex steps:

  1. Making a fixture that conforms to the part geometry.
  2. Securing the part in a fixture that guarantees repeatable positioning.
  3. Accurately locating the position of holes, cutouts and flanges according to the 3D part print.
  4. Preparing and utilizing a machine tool, die, punch, drill, saw or hand tool to process the part.
  5. Processing the part without deforming the part.
  6. Deburring or rework to insure high quality edge condition and contour.
  7. Repeating the process in the future when customer orders more parts.
  8. Modifying processes 1-7 when design changes occur in the part.

Steps 1-7 represent labor and/or equipment components with costly burden rates. More importantly, each step adds handling to the overall manufacturing time of the part, limiting production throughput. Kryton addressed all of these processing challenges by developing part fixtures, custom die punches and drilling fixtures; utilizing CNC lathes and machining equipment; and manually using hand tools on hard-to-access material removal or deburring.

Frequently, complex parts required multiple setups and secondary processing such as drilling, die punching, flange trimming and de-burring. Figure 4 depicts examples of a custom drilling fixture and a punching die for the secondary processing of parts. Note that the design, construction and inventory of fixtures and dies also contributed to the manufacturing costs and burden rates. As an alternative to in-house secondary processing of 3D parts, the shop outsourced some of the work to a local custom fabricator – which added costs and increased lead times.

This led the company to investigate a variety of CNC systems to improve 3D part processing, as shown in Figure 5.

The UW505 is equipped with the Siemens 840 control that manages all aspects of the cutting parameters, including dynamic power control, feed rates and assist gas pressures, tool paths, axis motions and related functions. The machine and control are configured to recognize the surface and center of the rotary table as the absolute point (0, 0, 0) of the work zone. This design feature facilitates the simple referencing of the part and fixture in the work zone. The absolute point also aids in the design of the part fixture as well as the CAD/CAM programming of the tool path.

Because the small-to-medium lot quantities of Kryton applications require fast setup and changeover, CENIT FASTRIM software was selected to provide the post processor and CADCAM programing for the UW505. Using CATIA software as a 3D CAD platform, CENIT can import 3D part models and quickly generate part fixture design, machine simulations and CAD/CAM programs for part processing.

Kryton has entered and processed over (90) different part numbers with the UW505 and CENIT software. Figure 13 shows three examples that were selected to represent a cross-section of typical applications on different shapes, materials and operations.

Part One is a metal spinning part which appears to be a simple .109 in steel can with a 10 in diameter transitioning to 6 in. However, the part requires the cutting of two slots, top and bottom flanges and a perpendicular longitudinal cut to create two identical halves. Accuracies are not critical with +.015 in, but symmetry of features is crucial. The production required multiple part handlings and machine setups. Processing 100 of these parts is summarized in Figure 14 to demonstrate the challenge of performing secondary cutting operations. Each part required five handlings, three machine setups, and the costly replacement of ten new $29.00 saw blades at 0.25 hours per blade setup.

In comparison, the UW505 processed the same 100 parts in one part handling and machine setup while eliminating de-burring and costly consumables, saving nearly 23 hours of labor and machinery burden rate – over $13.00 per part:

Description                 Setup Time: hours      Rate: parts/hour            Total Process Time

UW505 laser cutting              0.25                             60                                1.92 hours

TOTALS                                 0.25                                                                 1.92 hours

Part Two is a .120 in stainless steel tank made from metal spinning, with 19 holes located on the top flange and side walls. Hole diameters range from 1.5 in to 0.375 in with an accuracy specification of +.005 in. The hole locations require dimensional and angular placement precision. The tank diameter is 20.50 in and height is 24.75 in. To insure part accuracies and eliminate the risk of part deformation during the secondary processing, Kryton outsourced this part to a laser job shop.

Figure 15 details the processing steps, time and expense for outsourcing 100 of these parts to a laser job shop. The job shop’s CAD/CAM software and multi-axis laser capability were not disclosed, but the extra handling, preparations and production required approximately 11.50 hours for 100 parts.In comparison, the UW505 processed Part Two in two simple setups: cut 16 holes in the tank walls and then cut three holes in the top flange. The total laser cutting time for 100 pieces was 4.88 hours, approximately 42 percent less time than outsourcing – saving over $20.00 per part. The turnaround time to the customer was also reduced from over three weeks to less than one week. By eliminating costly packing and shipping of parts, paying for outsourcing and long lead times, Kryton saved time and money:

Description                             Setup Time: hours      Rate: parts/hour         Total Process Time

UW505 laser cutting 1                       0.25                             30                                 3.58 hours

UW505 laser cutting 2                                                           75                                 1.30 hours

TOTALS                                             0.25                                                                 4.88 hours

Part Three is manufactured by either metal spinning or a press operation. This .090 in aluminum dish has 16 precision holes ranging from 1.010 in to .166 in diameter. All of the hole diameters require tolerances of +.005 in and accurate dimensional placement on the disk of +.015 in. Because of these requirements and the critical part contour of the dish part, Kryton created a drilling fixture to locate and drill the holes. A .300 in x .300 in slot also required a custom die and punching operation. Outsourcing Part Three represented another alternative.

Figure 16 shows the in-house processing time for 100 pieces of Part Three, outlining the three separate material handlings and two setups needed for a low processing rate. Outsourcing to a laser job shop was quoted at more than $7.00 per part, not including the time and expense of packing and shipping.The UW505 dramatically reduced the production time for processing 100 of these parts, achieving the required accuracy and quality while saving approximately $5.00 per part versus in-house drilling and punching. This represents thousands of dollars per month since Part Three runs in large volumes.

Description                 Setup Time: hours      Rate: parts/hour            Total Process Time

UW505 laser cutting              0.25                             100                                1.00 hours

TOTALS                                 0.25                                                                   1.62 hours

After completing one year of operation, including the learning curve, Kryton summarized the benefits of the UW505 Fiber Laser Work Station:

  • Processing flexibility has been realized.
  • Multiple processing steps have been reduced to one laser cutting step.
  • Efficient fixture generation has reduced tooling production costs and expenses.
  • Elimination of rework has been realized for many jobs.
  • Better part accuracy and repeatability has been achieved on all parts.
  • Operator safety has been enhanced by reducing part handling and hazards.
  • Outsourcing has been dramatically reduced for challenging parts.

With the ROI and project payback estimated to be approximately 1.5 years before tax incentives and depreciation considerations, this investment in 5-axis laser processing with the UW505 has dramatically improved the secondary processing of these 3D parts.

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