By Jonathan Salem Baskin / Photos by Bill Elverman
“We started out with a CTL on steel tracks,” said Dan Seacat, a design engineer in Wichita, KS, referencing the early days of CASE’s Project Minotaur, the world’s first hybrid dozer/loader, which relied on the decades of experience the company has with designing and building dozers.
It also has expertise spread across its facilities: one of Seacat’s partners on the project was Ryan Ogg, who works eight hours away at the company’s facility in Burlington, Iowa, where it makes its 650M Crawler Dozer, among other products. He’s a design engineer with deep experience in dozer undercarriage track design.
Seacat and Ogg are part of a much larger team of engineers working on Project Minotaur. These engineers combined the ripper attachment designs of a grader and dozer to create a new one for Project Minotaur. They also did some best-in-class research on rear doors and came up with a new, improved design for Minotaur.
“Instead of beefing up at CTL, we started over with a heavy duty dozer undercarriage and adapted the design to the Minotaur’s smaller platform,” Ogg explained, noting that it involved using different, heavier and more roller mountings than would be normally found on an CTL, and a more robust cross-shaft design to withstand the increased loads from the dozer application across the chassis and undercarriage.
“Steel tracks had been a part of the plan from Day One,” said Seacat. “But for Minotaur, we wanted the entire track system to be more dozer-like in durability and capability, even if it wouldn’t be operated in a full-time dozer duty cycle.”
“We pulled proven design elements from both platforms, and built Minotaur based on proven technologies,” Ogg said. “But we’re using thicker materials and larger sections to stiffen it up.”
The result, according to Ogg, is a robust combination that will give operators more traction — “it bites in better” — and will let Minotaur work in more severe ground conditions. Steel might not move as fast as rubber, but it’s far more durable and more traction means increased push forces for dozing applications, plus rubber tracks may be an option for Minotaur customers who see its duty cycle primarily for lifting and loading.
The design process started with a small team sitting in a conference room in Wichita in early 2016, sketching ideas on paper of what Minotaur would look like, informed with deep market research and company expertise.
The process quickly migrated to computers, where design specs could be moved around to meet performance requirements. For instance, adjusting the linkage points (which define the path the arm would move) to stay within hydraulic cycle times and still meet lift performance requirements meant taking into account the location of the battery, tanks and other components of a highly compact system. Past real world testing and field experience informed all such decisions.
The real world testing only added to CASE’s confidence in the design and engagement with customers will add to it.
“You can model how things are supposed to fit together, but you won’t know how it truly works and feels until you have an operator behind the controls,” said Jacob Benteman, design engineer.
Project Minotaur is a new machine that will bring dozer and CTL functionality to worksites in a single unit, but it relies on mature, proven technology that will make it easier to manufacture, sell and, when necessary, service.
The CASE team looked, as it always does to ensure reliability and provide a common look and feel for customer interfaces, at the best features of its range of products – from skid steer loaders (SSLs), compact track loaders (CTLs) to dozers and backhoes — and liberally borrowed lessons learned and best-in-class ideas from across its offering.
Sometimes, the innovation challenge meant finding new components, like a pump to drive the motor, or increased tubing size to yield better flow and performance, so the team researched components and, in most cases, worked with its existing, proven suppliers to find the best solutions.
“There’s an assigned manufacturing person capturing video of each prototype build on a daily basis, which is then shared with the team to create the best installation process,” said Murali Mani, who’s focused on Minotaur’s hydraulics system. “They’re looking for a ways to enhance the current assembly line setup with the help of Minotaur.”
“One place we should see the benefit of using proven technology and reliable components will be in the field,” added Tim Hinkle, design engineer, who works on engine dress systems (intake, exhaust and cooling). “There’ll be less to learn for dealers and parts will be familiar to the service techs, so they can leverage their existing capabilities.”
“It needs to survive what customers throw at it, since we’re part of a tough — oftentimes grueling industry. We need to get at the durability of the thing,” said Eric Waters, lead test engineer.
He’s describing FEA testing, a go-to tool used to develop new products, which is playing a key role in the continued development of Project Minotaur.
He continued: “We start out with an estimate of the load we think the machine can withstand, which is the static load. Then we want to look at how much stress does that generate and you know, how much is something going to bend?”
“We want to understand cycle count and loading, so the static test turns into a dynamic one, from which we can estimate the durability of the machine under real world conditions,” added John Moffitt, design engineer.
FEA, which stands for finite element analysis, is a proven methodology for studying the properties of machine components. The Minotaur team combines experts in product validation, product engineering and design analysis to pull together tests that mirror real-life. The challenge is that Minotaur is the first of its kind.
“They’re complex models,” Moffitt continued, “modeled with the material and weld classifications defined and we use a lot of actual field load data to look at not just one load case, but what’s happening in maybe a hundred different static loads in a series over time.”
“Really, what we’re talking about is virtual fatigue analysis,” Waters said.
The team is implementing cutting edge analysis tools for simulation to test a completely new machine, but it stays grounded in their deep expertise in building site-ready equipment. It’s an approach we call practical innovation.
“There are things customers do with our machines that we never could have imagined,” Waters added. “So while we may be surprised by the reality of what our machines are put through, we’re testing to account for the unexpected in our dynamic loading.”