DNMGinsert

The physics of metalcutting are all about energy and geometry. The energy comes from the spindle rotation. That energy converts to heat, which is why choosing the correct cutting speed (SFM) is important. Then it’s up to the geometry of the cutting tool to take that energy (heat) from the spindle rotation to reach the yield strength of the workpiece material and to separate the chip. When you’re successful in this separation process, then the grade of carbide determines tool life or the ability for the insert to resist breakage. Spend the necessary time to find the correct insert geometry (often oversimplified as “insert chipbreaker”), then look at the grade choice.

Michigan Electric Racing (MER) was a student team at the University of Michigan whose mission was to design, build, test, and finance our own high-performance, all-electric Formula-style race car. The team competed at the Formula SAE competitions each summer against teams from all over the world. MER started as Michigan Hybrid Racing (MHR) in 2012. In 2018, the team underwent a transition to fully electric vehicles and constructed two electric formula cars in 2019 and 2021. In 2021 the team placed 1st at Michigan FSAE and in 2019 2nd at FSAE North. In the 2022 completion year, the MER merged with MRacing to form a collective team with the knowledge of MER electric powetrain and MRacing’s experience.

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TechMet Carbides is an independent, privately owned company that began in 1998 with the goal of providing world-class tungsten carbide technology and products.

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There is no perfect answer here, because the variables are far and wide. There are, however, guidelines that can be quite helpful.

MER19 was the team’s first all-electric vehicle. Every aspect of the vehicle was designed from the ground up, building on experience from the hybrid competition. MER19 exceeded expectations, with a second place finish at the team’s first electric competition.

When it comes to maximizing your tooling investment, it pays to find the right partner. TechMet offers a new and better option. Backed by 25 years of experience as the number-one supplier of carbide rod in North America, they have the experience and focus on quality to deliver superior value. TechMet carries over 1,000 of the most commonly used indexable tool types—including turning inserts, Notch-style grooving and threading inserts, laydown threading inserts and more. All in stock and ready for same-day shipping. Best of all—they offer free trials so you can shop with confidence. Learn more about TechMet’s indexable cutting tool offering here.

From 2012 to 2018, MHR constructed and developed hybrid vehicles to compete in FSAE Hybrid. Using the knowledge from these years, MER was able to construct competitive hybrid vehicles and race them at the New Hampshire International Speedway.

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Experienced operators know that the workpiece print dictates the shape of the insert for a given operation. Size of the insert will be determined by the amount of material that needs to be removed, the machine and the set-up stability. Once you’ve whittled down your options based on those criteria, there is no magic bullet or ChatBot to get you to the perfect insert choice. There are, however, three baseline decisions that can help spell success for any insert purchase.

CVD-coated inserts are best exploited at high cutting speeds (SFM), and continuous heat (for example, external turning in steel or cast Iron machining). CVD Coatings are usually highly specialized for one or two application areas. If a shop is frequently cutting the same range of workpiece materials for those types of applications, it might make sense to conduct trials and optimize with a handful of high-performance CVD-coated grades.

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VNMGInsert

Let’s face it, selecting the optimum turning insert for each application can be a daunting task. With hundreds of thousands of different inserts available from dozens of suppliers, how can you make the process more manageable?

Negative rake inserts are most often double sided, which provides good economics. They’re also easy to index, strong and reliable. For this reason, we generally default to double-sided negative rake inserts as a first choice. Positive rake inserts provide much lower cutting forces—a big advantage on smaller workpieces, unstable set-ups, and more difficult to machine alloys.

PVD-coated inserts are very much at home in stickier materials, running at more moderate cutting speeds; and applications where having a “sharper” edge improves the performance of the operation. Small diameter boring is an area where a PVD grade will likely be the better performer. Most milling applications on smaller machining centers will benefit from PVD-coated inserts. PVD coatings almost always have a wider range of materials for which they can perform well. For shops that don’t know what material they’ll be cutting from one day to the next, PVD-coated inserts are generally the best choice.

There is a long standing rule here: The right geometry insert in the wrong grade will always outperform the right grade in the wrong geometry. Memorize that rule and be sure to tell everyone on your team that is involved in insert selection.

MER21 was Michigan Electric Racing’s second complete vehicle. The COVID-19 pandemic caused several delays but with perseverance, the MER team was able to construct a car performing 1st in 5 of 6 categories and 1st overall at Michigan SAE.