At one point in time, Magnum Machining Inc. processed the majority of its parts with a bevy of vertical machining centers (VMCs). Unfortunately, that type of machining platform didn’t quite mesh with the shop’s part-production needs. What did prove to be the perfect production match? Horizontal machining centers (HMCs), which helped the Deerwood, Minnesota-based shop boost its speed, consistency, process flexibility and overall productivity.
According to Michael Bowman, CEO of Magnum Machining, the verticals required that operators stop the machine, open its door, clamp a part in a fixture, close the door and restart the machine every time they loaded a new part. All this happened while the machine’s spindle sat idle, non-productive and waiting. Additionally, the shop’s parts – mostly medium to large castings – often involve deep holes and features that require long tool overhangs. The VMC’s were unable to provide the necessary reach and stability for such operations.
By the sheer nature of their robust designs, HMCs deliver all the necessary support and stability for the long-reach milling, drilling and boring operations the shop needed to produce even higher quality and more precise parts. On top of that, HMCs, according to Bowman, provide Magnum with virtually 100 percent machine spindle utilization, as their integrated 2-pallet changers allow parts to be loaded/unloaded while machine spindles continue to work uninterrupted. HMCs also typically have larger work envelopes, which give the shop the added processing flexibility it needs to run either one or two big parts, or several smaller parts on the same machine platform.
As a result of its switch from a house of VMCs to one of HMCs, Magnum now has 16 various models of HCN Series Horizontal Machining Centers, all from Mazak. That represents about 68 percent of the shop’s total number of manufacturing systems and includes HCN-4000s, 5000s, 6000s, 6800s and 8800s. Most recently, the shop added two HCN-5000s, one 6000 and a 6800, all of which feature Mazak’s MAZATROL SmoothG CNC.
The control makes it easy to generate programs for processing complex parts through off-centerline machining as well as angled drilling, milling and tapping operations. It incorporates a wide variety of advanced programming functions that give Magnum complete ease of use and ensure high-speed, high-accuracy machining performance. Some of those functions include High Gain Feed Forward Control to boost machining speed and accuracy, Real Time Tuning to ensure optimal machining balance as workpiece weight changes and Variable Acceleration Control to calculate optimal acceleration for a combination of axes.
Ergonomics also play an important role in the functionality of the MAZATROL SmoothG control. A large 19" display presents all of the critical machine data within a single-page view, while the tilt control panel allows for optimal positioning based on operator height. An intuitive multi-touch screen similar to those found on smartphones enables fast and smooth programming operations, which can be stored on an SD card allows the CNC to store up to 32GB of data.
Its lineup of Mazak’s HCN Horizontal Machining Centers provides Magnum with a combination of outstanding value and high-performance features that allow the shop to achieve maximum productivity when working with virtually any type of casting material. The machines require minimal floor space, yet still provide exceptionally wide machining areas for the shop’s large workpieces or multiple smaller ones.
The HCN machines’ pallet sizes range from 400 mm square to 800 mm square, while spindles are from 40 -taper/12,000-rpm to 50-taper/10,000 rpm. The machines also boast the industry's fastest 2-pallet changer as standard equipment that provided a rotating front pallet for easy set up.
Having all Mazaks, according to Bowman, dovetails perfectly with the shop’s particular HMC manufacturing strategy and the increased workflow flexibility it enables. “We know that once we prove out a program on our Mazaks, the machines are so consistent that we know that every time we run that particular job in the future, there will be zero variation,” he said. “The consistency and speed of the machines also allow us to run more jobs ahead of time. Plus, we always strive to reduce setup time and increase productivity by using fewer machinists to produce more parts.”
To accomplish this, Magnum will run multiple parts simultaneously whenever possible to shorten job turnaround times. This is why the shop’s HMCs prove more advantageous than VMCs, according to Bowman. “On a VMC, we might have room for maybe two parts, while on a Mazak HCN, we can load three or four of those same size parts on each side of a four-sided tombstone fixture,” he said. “Machine time for each individual part might remain the same, but we have eliminated the costly production idle time involved with the load/unload process for VMCs, so our overall job turnaround time is much shorter as well.”
While its Mazak machines practically guarantee increased productivity via high process speed and consistency, Magnum still relies on talented industrious individuals to work together with that advanced technology. Unfortunately, the skilled labor pool in Magnum’s surrounding area has shallowed out significantly since 2013, though Bowman observed that the situation continues to slowly improve as local tech school admissions grow.
Bowman strives to ensure the shop has the internal training capacity to hire individuals with any mechanical aptitude or desire to learn. He also boasts that within 30 to 45 days, these trainees, as a result of Magnum’s training, are able to operate machines, navigate the controls and do their own part inspections.
What makes this short learning curve possible, according to Bowman, is a combination of the training program itself and the shop’s manufacturing equipment, specifically its Mazak machine tools and their user-friendly MAZATROL SmoothG CNCs.
“When you compare machine controllers in the past to those of today, such as the Mazak MAZATROL SmoothG control,” explained Bowman, “there are significant differences. For one, the newer Mazak control was designed with today’s younger individuals in mind. Its look and functionalities are similar to those of a today’s tablets and smartphones, so there is an immediate comfort level with the younger machinists when they can work with such a machine control.”
Shane Cartie, maintenance manager at Magnum Machine, echoes Bowman’s opinion about the MAZATROL SmoothG, adding that the control’s advanced functions – such as those for maintenance, usability and customization – further enhance ease of use and shorten the learning curve.
When it comes to parts and production, Magnum is not a job shop per se, according to Bowman, but instead a full Tier One supplier that does mostly contract manufacturing of recurring jobs. That means the shop often knows exactly what to expect at what time and can plan production flow accordingly. Such reoccurring job lot sizes run anywhere from five pieces to 2,500. For some jobs, the shop will produce 20,000 parts per year; for others, only five parts are needed annually.
Magnum specializes in the machining of castings and does some bar-type work for a customer base that spans industries ranging from heavy equipment to commercial HVAC. Most cast parts are made from gray and ductile iron, steel, stainless steel, aluminum or brass and can each weigh as little as a half of a pound to as much as 700 pounds. Machining cycle times can vary from 1.5 minutes to upwards of six hours.
Part-machining operations include turning, milling, drilling, boring and tapping. Magnum strives to reduce cycle times, not only to reduce cost per part, but to also increase capacity to take on more work. As noted by Shawn LaFava, general manager at Magnum Machining, “The key is how quickly we can make the capacity available to get more hours per spindle. We regularly determine our capacity based on available employee and machine tool spindle hours and try not to go above 75 percent machine capacity. At this level, our customers know we can respond quickly and will come to us for any emergency jobs.”
Magnum’s commitment to its customers’ success and its efforts to always maintain mutually beneficial relationships is rooted with Bowman’s father, Jerry Bowman, who established Magnum Machining in 1994 in Rochester, Minnesota. The family had a cabin in the Deerwood area, and in 1997, Jerry expanded operations to the area.
The shop’s current facility started as a single building that was subsequently expanded to bring the Rochester facility’s work up to Deerwood. The Deerwood facility currently employs 72 people. Magnum has also opened a facility in Mexico that essentially mirrors the Deerwood shop in terms of customers, production levels and types of workpieces.
“As my father always did, we will continue to place our relationships with customers first. We will continue to build on these and help fulfill their needs, so that all parties involved are successful and prosperous,” said Bowman. “In our industry sector, any stability we can get, especially from our production equipment, is one less really critical issue to worry about on a daily basis and helps strengthen customer relationships.
“Support from both Mazak and Northwest puts us at ease,” he continued. “If we do have problems, they value the relationship we have with them as much as we do and will make every effort possible, as quickly as possible, to get us back up and producing.”
Original article in Advanced Manufacturing