GWS Tool Group has filled two of its California/Northern Mexico roles. Bryan Comyns will be the company’s business development specialist in the region, while Walter Lopez will be its regional application specialist.
Bryan will be responsible for developing Carbide Milling Insert and maintaining client relationships, identifying ways to promote and maintain brand relevance. He will also work in tandem with local application specialists to generate new business opportunities and understand and adjust for regional customer needs and trends.
“Bryan’s strong background in project management, customer satisfaction and adding enthusiasm to the GWS Tool brand will immediately add value to our customers,” says Scott Tiehen, director of Sales – West.
Walter will be responsible for supporting GWS distributors and key metalworking customers in the Coated Inserts application of GWS high-performance cutting tool solutions. Cutting tools from GWS include both standard and purpose-built tooling, such as end mills, form tools, step tools, drills, reamers, taps, PCD-tipped tooling and countless variations of special turning inserts.
“Walter’s extensive metalworking and process improvement experience is an ideal fit for our organization,” says Tiehen. “He will immediately add value to our customers with his aerospace background and experience working with key channel partners and end-users.”
Whipple Superchargers’ more advanced rotor machining process means its power adders have become more potent.
Founded by former race crew chief and car owner Art Whipple in 1987, this Fresno, California, company manufactures twin-screw superchargers for automotive and marine racers and anyone else looking to improve their engine’s performance. As one of a few different types of “power adders,” as they are commonly referred to (turbochargers and nitrous oxide are others), superchargers introduce additional air into an engine beyond what the engine can pull on its own. The more air that can be delivered into the engine, the more fuel that can be proportionally added. That means the engine’s displacement becomes “bigger” than it physically is, producing more horsepower.
The accurate, non-contact meshing of two helical rotors inside a casing is the key for proper function of twin-screw superchargers. With the Whipple design, the male rotor has three helical lobes and the female has four, explains Supercharger Designer Garrett Bright. These rotate counter to each other and extremely closely. As the lobes of each move past air inlet ports, the air becomes trapped between the rotors and casing. Rotor rotation progressively reduces the space the air occupies, compressing it. Compression continues until the inner-lobe RCMX Insert space becomes exposed to an outlet port, through which the air is discharged higher than atmospheric pressure into the intake manifold that sits atop the engine.
Supercharger efficiency depends on how effective sealing is between the mating rotors and the casing. Until recently, Whipple had solely used rotors manufactured and supplied by a European company. It still uses those supplied rotors for some of its supercharger models. However, Whipple has since started to design and machine its own rotors in house, and the machining process it has developed produces more cylindrical and accurate rotors than those its supplier provides. In fact, more precise machining means new supercharger designs are 5% more efficient than those using the supplied rotors.
Getting to this more accurate machining process took time. But with DCMT Insert the help of advanced measurement, machine tool, workholding and tooling technology (and guidance from the companies that make that equipment), Whipple has established a means for not only accurately machining its rotors, but also minimizing changeover times and upping cutting aggressiveness to reduce cycle times.
Mr. Bright says Whipple was spurred to machine its own rotors after seeing the results from precise measurements of its supplier’s rotors taken on its Zeiss Accura coordinate measuring machine (CMM). This CMM features a rotary table as well as Zeiss’ Vast scanning technology and Gear Pro option in its Calypso measuring software. Mr. Bright says this software is particularly effective for measuring mating rotors because he can assign specific control points on the male and female rotor helical profiles where they meet to determine the clearance between the two at those points. Mr. Bright determined that the profile for each rotor should be ±63 microns with the goal of achieving a clearance of approximately 125 microns. The company wasn’t getting that from its rotor vendor.
Whipple’s rotor-machining process using form tools is similar to that of its supplier’s, but with modifications to increase rigidity. The machine Whipple purchased in October 2016 is a Mazak Integrex e-420H-S II turn-mill with B-axis milling head. Cylindrical 6061 aluminum rotor blanks are first center-drilled longitudinally on another machine to enable a steel shaft to be pressed into them. As an operator loads a blank into the Integrex, the machine’s main spindle and then subspindle clamp on the shaft’s protruding journals. Next, the machine’s B axis is drastically tilted to orient a custom form tool that matches the desired flute profile when at that angle (see this story’s opening photo). Finally, the spinning form tool is moved along the Z axis as the rotor is slowly rotated to create each flute in multiple passes. “At this point, what we have here is a high-end, two-axis lathe,” Mr. Bright quips.
Initially, Whipple used extended-length, pull-back-style ER collets to clamp on the shaft journals. The extended length was required to position the blanks away from the subspindle to provide sufficient clearance for the B-axis spindle to tilt as far over the subspindle’s chuck as necessary. However, the pull-back functionality of those collets made loading rotor blanks time-consuming and challenging. Collet tightening (resulting in pullback) put excessive load on the main spindle, meaning the W-axis subspindle had to be trammed-in to help dial-out the load. Otherwise, chatter or poor surface finishes could result. As a result, operators such as Chris Jensen would continually clamp and reclamp until most of the load was eliminated. This typically took 10 minutes. Plus, Whipple was constantly replacing collets due to the wear they experienced being tightened and loosened so many times.
At the advice of Kellen Bush, Mazak’s application engineer who worked with Whipple on this project, the company contacted Hainbuch to devise an alternative workholding approach. Hainbuch Sales Manager Tom Chambers explains that the company’s custom workholding solution not only provides the extended reach required to enable the machine’s B axis to tilt to the requisite angle without interference, but it also offers higher rigidity while simplifying changeovers. This is possible largely because dead-length collets are used instead of pull-back types. Mr. Chambers says dead-length collets “clamp in space,” meaning the rotor blanks will not move when the collets are clamped. As a result, no additional load that would have to be dialed-out is applied to the main spindle. Changeovers now take only 2 minutes.
The Kyocera Unimerco form tools Whipple uses to machine its rotors (as does Whipple’s European supplier) actually are not commonly used for cutting metal. Anders Varga, sales manager for Kyocera Unimerco, says this type of tool is typically used for cutting wood, composites and other fibrous materials. This is primarily due to the amount of pressure that would be exerted on the tool as a result of the high contact area between a metal workpiece and long insert cutting edges. That these tools can be used in this rotor-machining application speaks to the rigidity of the machine with Capto spindle interface and its custom workholding.
Using form tools that match the rotors’ helical flute profile (profiles Mr. Bright has refined) eliminates polishing that might be required if multiple end mills were used to carve the flutes. The rotors are machined so their lobes are as big as possible, but slightly undersized to allow for a subsequent proprietary coating. Whipple typically keeps two roughing tools and three finishing tools on hand for both male and female rotors. The tools use uncoated, micro-grain carbide inserts. The inserts for the roughing tools are attached to the tool bodies via screws; finishing tools are brazed to them.
Not only is Whipple’s machining process achieving the 125-micron clearance goal between mating rotors, but end-to-end rotor cylindricity is more consistent. Mr. Bright says that with the original workholding approach, the difference in cylindricity of one end of a rotor compared to the other might be as high as 10 microns. Now, that has been reduced to 1 micron. Rotor cycle times are a tad faster, too. Cycle times for a male rotor is 14 minutes and a female rotor takes 20 minutes. But for Whipple, this is gravy. Its primary goals were to achieve higher rotor machining precision and speeding changeovers, both of which it has realized.
Wear of tungsten steel cutting tools
Wear form
The basic pattern of milling cutter wear is similar to that of turning tools. The cutting thickness of high-speed tungsten steel milling cutters is relatively small. Especially during the up and down milling process, the teeth of the workpiece are compressed and slip more severely, so the wear of the milling cutter mainly occurs on the back. When using tungsten steel face milling cutters to mill steel parts, due to the high cutting speed, the chips slide at high speeds along the front, resulting in wear at the rear and less wear on the front milling cutter.
The tungsten steel face milling cutter carries out high-speed intermittent cutting, which makes the cutter teeth bear repeated mechanical and Thermal shock, resulting in cracks and fatigue damage of the cutter teeth. The higher the milling speed, the faster and more severe the wear of the milling cutter. Most tungsten steel face milling cutters lose cutting CNC Inserts ability due to fatigue damage. If the geometric angle of the milling cutter is improperly selected or used, and the strength of the cutter teeth is poor, the cutter teeth will wear out without cracks after bearing a large impact force.
preventive measure
(l) Reasonable selection of milling cutter blade grade: Blade materials with high toughness, low thermal cracking sensitivity, and good heat resistance and wear resistance should be used. For example, blades such as YS30 and YS25 can be used when milling steel; When milling cast iron, YD15 and other blades can be used to prevent milling cutter wear.
(2) Reasonable selection of milling volume: Under certain processing conditions, there is a safe working area that will not cause damage. Selecting Vc and ? z in the safe working area can ensure the normal operation of the milling cutter and prevent the wear of the milling Cermet Inserts cutter.
(3) Reasonable selection of the relative position between the workpiece and the milling cutter: Reasonable selection of the installation position of the face milling cutter plays an important role in reducing the wear of the face milling cutter.
Most turning center users use wear offsets for the purpose of holding size over the course of a production run. And with most of the tools used on turning centers (turning tools, boring bars, grooving tools, among others), all production run sizing should be done with wear offsets. And since tool nose radius compensation does not help with sizing, most computer aided manufacturing (CAM) system programmers will generate motions based upon the tool nose radius size to be used and will not even use the CNC-control-based feature tool nose radius compensation.
There is at least one time when tool nose radius compensation can help with PVD Coated Insert sizing right at the machine during a production run. Whenever the insert of a tool must machine with over 90 degrees of its cutting edge is probably a good time to think about using tool nose radius compensation for sizing purposes. Consider, for instance, button tools that can machine with up to 180 degrees of their inserts. Look, for example, at the diagram at right.
In essence, this button tool can machine on both sides of the round insert during one cutting motion around the sphere. As the tool begins to wear, the diameter of the sphere being machined by the button tool will change. In the example, normal wear offsets will be of little help when it comes to the sizing required due to tool wear, since adjusting them would have the tendency to make this sphere egg-shaped.
Instead of adjusting wear offsets to hold size in this kind of application, the tool nose radius compensation offset (commonly specified in the offset table under the R register) will be changed. Say, for example, that after 50 workpieces the sphere shape being machined in figure one grows by 0.0004 inch in diameter due to tool wear. In this case, the R register offset value (commonly the tool’s radius) can be reduced by 0.0002 inch. The next time the program is run, the control will keep the tool 0.0002 inch closer to the surface being machined, reducing the diameter of the ball Carbide Milling inserts by 0.0004 inch. Sizing with tool nose radius compensation on turning centers in this fashion is similar to sizing the XY motions on machining centers when cutter radius compensation is used.
A wealth of equipment can enable machine shop employees to do their jobs more effectively. For example, spindle touch probes can simplify setups, quick-change workholding devices can speed changeovers, automated processes can minimize burdensome tasks and so on. All of this technology is readily available to help shops maximize their overall return on employee investment while enabling employees to expand their shopfloor skillsets.
Marshfield, Wisconsin’s Hastreiter Industries, a family-owned shop and 2018 Top Shops winner, is home to a rather extreme example of this, one that has impacted a specific employee’s manufacturing career and her life Carbide Turning Inserts in a significant way. What is it? It’s goggles with magnifying camera technology that gives Tia Bertz, a legally blind young woman who now works in the shop’s quality control department and supports the company’s IT and CAD needs, 20/20 vision.
Born in South Korea, Ms. Bertz has lived in Marshfield since she was adopted at 17 months old. Since birth, she has had optic nerve hypoplasia. Being a techie, she says this condition is akin to having a bad Ethernet cable between a good network client and server. Her eyes and brain function just fine, but the connection between them is faulty.
Ms. Bertz’s introduction to manufacturing occurred in high school. During her sophomore year at the Wisconsin School for the Blind and Visually Impaired in nearby Jamesville, the school purchased a MakerBot Replicator 2X plastics 3D printer. Intrigued, she TCGT Insert took a class one semester that enabled her to experiment with the machine. Her interest in 3D printing was rekindled during her senior year when the school purchased a Lulzbot Taz 5 3D printer. This sparked her maker-mindset, and she began using basic Tinkercad CAD software to design and print various projects. She also read the printer’s operating manual just for fun. Ms. Bertz eventually became the school’s 3D printing instructor and purchased her own Taz 5 for use at home. There, she performed side jobs such as printing tactile astronomy projects for the Yerkes Observatory in Williams Bay to offer to visitors with visual impairments.
Rather than let her disability define her, Ms. Bertz continued to seek opportunities to leverage her growing skill. “I could have spent the rest of my life in my basement simply 3D printing models,” she says, “but why? I’d much rather inspire those with disabilities such as mine to make significant contributions to society, too.”
In fact, a couple years ago, an opportunity presented itself for Ms. Bertz to do just that when she met members of the Hastreiter family through church.
Formerly known as UTM Inc., Hastreiter Industries was founded in 1988 by Ken and Sondra Hastreiter. Kylan, their son and company vice president, says they were impressed with Ms. Bertz’s talents and smarts. At the time, she was attending Northcentral Technical College in pursuit of her CAD technician associate degree. Believing she could be a valuable member of their team, they sought to identify a role for her while determining what tools she’d need to effectively perform her duties given her visual impairment. The first step was inviting her to visit their shop.
Kylan Hastreiter says one of the first things they did was walk with Ms. Bertz through the shop so she could describe specifically what she could see in the facility. (This was at the shop’s previous location also in Marshfield. In the fall of 2019, the company moved to its current 42,000-square-foot, environmentally controlled building.) The communicative walk-through helped identify potential safety issues. It also shed light on what tasks she would be able to perform and what assistive technology might be required to facilitate them.
After those initial discussions, the shop brought her on as an intern in August 2018. Early on, Ms. Bertz primarily performed CAD modeling. However, as a job shop, Hastreiter Industries offers only so much of that work. If she became a full-time employee, which was the goal, “what else would we be able to call upon her to do?” Mr. Hastreiter recalls wondering. ?Ms. Bertz expressed interest in metrology, so the shop considered what her role in its QC department might look like.
The timing of all this is intriguing. She was brought on as an intern one month before the International Manufacturing Technology Show (IMTS) in Chicago. Some of the Hastreiter Industries team was planning to attend, and they invited Ms. Bertz to join them toward the end of the show.
“While walking the show with Tia, we encountered a virtual reality, digital-twin demonstration and learned that she had never experienced VR,” Mr. Hastreiter says. “The demonstration included a virtual factory with assembly projects that those using the VR goggles could attempt in that environment.”
“I thought either I’d do really well in a virtual environment because of my experience with 3D CAD modeling, or I’d epically fail,” Ms. Bertz says. “I fumbled around during the assembly demo at first, but eventually got the hang of it. The person hosting the demo said I did better than many people with excellent vision. That’s when I realized I could function better in a virtual environment than the real world.”
The thought occurred to Mr. Hastreiter that if Ms. Bertz can see in a virtual environment presented very close to her eyes by way of goggles, why not have a camera present a feed of the real world to her in a similar way? Research showed that such technology already existed in the form of the E2 wearable electronic magnifier for low vision from NuEyes. The E2 is a pair of VR goggles integrated with a high-definition, auto-focus camera and software to enable zooming in and out, changing contrast and performing optical character recognition (OCR). The device has a 3K display (1,440- by 1,600-pixel screen resolution) and 101-degree field of view.
The shop, along with the Wisconsin Division of Vocational Rehabilitation (DVR) — a government agency that works with clients to determine what assistive technology is needed for school and work — set up an E2 demonstration for Ms. Bertz. This was through Adaptive Technologies Resources, a reseller of NuEyes products. At first, the goggles were disorienting, she says. But once she got the hang of it, she was seeing things that were either entirely new or that would have been impossible to see before without positioning her head a couple inches away from an object. “I was like, ‘Wait, I can read the sign at that far wall and see the ball on the CMM probe stylus without getting very close to it,’” she says. “I could also actually see cutting tools in our machines, which I couldn’t before.”
Ms. Bertz explained to her DVR contact that to perform her QC duties at the shop, she would need the E2 goggles as well as digital hand gages. Gages with digital readouts were needed because she could not see the graduation markings on conventional Vernier devices. She also requested a touchscreen computer.
“We noticed that Tia needed to position herself right up against a computer screen to see it,” Mr. Hastreiter explains. (The camera in the goggles doesn’t help when looking at a computer screen.) “But when you’re that close, how do you know where the mouse cursor is? Having a touchscreen eliminates the need to locate it.”
Now with the goggles, the digital hand gages and the touchscreen computer, Ms. Bertz can independently perform part inspection duties and easily read complicated part prints with small text. She also measures parts using the shop’s vision system, which she says is ironic given her visual impairment. Hastreiter Industries hired her as a full-time employee in May 2019, and has started training her to program and operate its Hexagon 7.10.7 SF shopfloor CMM. Once that training is complete, the goal is to promote her to the second-shift QC department lead. “That’s perfect for me because I’m not a morning person,” Ms. Bertz jokes.
This experience has inspired Ms. Bertz to set a long-term goal of creating an ISO-like standard to help manufacturers safely accommodate employees with visual impairments. That way, they are not reinventing the wheel and won’t have to hire an expert in accessibility techniques and technology.
For now, though, she suggests that manufacturers considering hiring visually impaired people to do their homework relative to assistive technology currently available such as the E2 goggles. She also recommends contacting a state’s equivalent to DVR to determine what resources it has to assist a shop’s efforts. But Ms. Bertz says what’s most important is really getting to know the individual with the visual impairment. Open communication between shop management and the individual is paramount to a satisfying work experience and ensuring that person has the right tools to succeed and thrive.
