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3 Steps to Shutting Up Tool Chatter

Cutting tools undergo a great deal of force during the machining process, which cause vibrations – also known as chatter or harmonics. Avoiding these vibrations entirely is not possible, though minimizing them is pivotal for machining success. Vibrations become damaging when proper machining steps are not followed. This leads to strong, part-ruining chatter. In these situations, parts have what is known as “chatter marks,” or clear vibration marks along the surface of a part. Tools can experience an increased rate of wear due to excess vibration.

Tool Chatter can be kept at bay by following three simple, yet often overlooked steps:

1. Select the Right Tool for Your Job

It seems elementary, but selecting the best tool for your application can be confusing. With so many different geometric styles for tooling – overall length, length of cut, reach, number of flutes – it can sometimes be difficult to narrow down one specific tool for your job. Oftentimes, machinists opt for general purpose tooling that can perform a variety of operations, overlooking the option that’s optimized for one material and job.

Opting for Material Specific Tooling is helpful, as each material has different needs. For example, steels are machined differently than aluminum materials. Everything from the chip size, to chip evacuation, is different. Variable Helix or Variable Pitch designs help to minimize chatter by reducing harmonics, which are caused by the cutting edge having repeated contact with the workpiece. In order to reduce harmonics, the time intervals between flute contact with the workpiece are varied.

Overall length is another important factor to consider when deciding on a tool for your job. The more overhang, or length the tool hangs from the spindle, the less secure the spindle-to-tool connection is, and the more vibration. Ensuring that your tool is only as long as needed for your operation is important to minimizing chatter and harmonics. If machining deep within a part, opt for reached tooling or an extended reach tool holder to help solidify the connection.

2. Ensure a Secure Connection

When it comes to secure tool holding approaches, both the tool shank and the collet are important. A loose tool, unsurprisingly, has more ability to move, or vibrate, during machining. With this in mind, Helical offers Shank Configurations to help the connection including the ToughGRIP Shank, which replaces a smooth, mirror-like surface with a rougher, coarser one for increased friction. Helical is also a licensee of the HAIMER Safe-Lock™, added grooves on the shank of a tool that work opposite of the spindle rotation, securely fastening the tool in place.

Machinists must also know the different types of collets available to them to identify if a better solution might be necessary. For example, Hydraulic Tool Holders or Shrink Fit Tool Holders promote a stronger connection than a Mechanical Spindle Tightening method.

For more information, see Key Tool Holding Considerations

3. Choose a Chatter Minimizing Strategy

How a tool is run can mean the difference between stellar job results and a ruined part. This includes both the parameters a tool is run at, as well as the direction by which it rotates – either a Conventional Milling or a Climb Milling technique.

Conventional Milling

In this method, the chip width starts from zero and increases gradually, causing more heat to diffuse into the workpiece. This can lead to work hardening, creating more headaches for a machinist.

tool chatter

Climb Milling

Most modern machine shops will use a climb milling technique, or when the chip width starts at its maximum and decreases during the cut. Climb Milling will offer a more consistent cut than traditional methods, and puts less stress on the tool. Think of it like weight lifting – doing the heavy lifting will be easiest at the beginning of your workout. Similarly, a cut in which the thickest chip is removed first helps the tool maintain its strength. Because the chip cutting process is more swift, vibrations are minimized.

decrease tool chatter

For more information, see Climb Milling Vs. Conventional Milling

In Conclusion

Vibrations are unavoidable during the machining process, but minimizing them can mean the difference between successful machining and scrapped parts. Following three simple rules can help to keep your chatter and harmonics under control, including: Selecting the right tool, ensuring a secure machine-tool connection, and using it in a climb milling strategy. Both Harvey Tool and Helical Solutions have tools that can help, including shank modifications and Variable Helix or Variable Pitch end mills.

Anderson Prototypes – Featured Customer

Anderson Prototypes is a custom machine shop in Port Moody, British Columbia. Working with everything from Titanium to Bamboo, they create mechanical mechanisms and working prototypes of new technology. By applying 25 years of experience with manual and CNC machinery, they craft amazing parts, some even bordering on impossible. The team at Anderson Prototypes works in a variety of industries, ranging from large-scale prototype work to small batch production, machine repair, and even movie and TV props.

Jim Anderson, a 30 year veteran of the manufacturing industry, is the Founder and Owner of Anderson Prototypes. We caught up with Jim and talked to him about some of the “impossible” projects his team likes to take, his experiences in the film industry, and his advice for the aspiring machinist.

Tell us a bit about your shop, how you got started, and what sort of products you manufacture.

I started in machining in 1985, as a full-time student in a machining class at a local community college. I spent years working in jobbing shops, plastic mold injection shops, and specialized start-up companies, scratch building a range of things from high-speed water “pouch” filling machines to hydrogen fuel-cells. Today I work with a wide range of clients including 3 submarine companies, a military contractor, companies that use custom built or modified ROVs and drones, food packaging companies, production companies needing film and TV props, and more.

What made you get into machining?

I have always been an actively creative person, and I enjoyed wood and machine shop in high school. I found a creative outlet for my talents to build and fix things inside the machine shop environment. I continue to study machines and items, to understand how they were made, and how it could be made better or simplified.

anderson prototypes

What is your favorite part of this profession?

I always enjoy creating something for a client that they have been dreaming of, sometimes for years. They come to me with a sketch on a napkin or a verbal idea, and I turn that dream into reality. When they come to pick it up and see it for the first time, the emotions are tremendous!

What sort of machines do you use in your shop?

I have 2 Tormach 1100 CNC mills, one 4 axis and the other 3 axis, a Sherline 2000, 4 axis CNC mill, a Frankenstein CNC lathe with a 8 station tool changer for small work, a Milltronics ML-17 CNC lathe, a Colchester Student Engine Lathe, and a smaller manual milling machine. I also have drill presses, tapping heads and tons of specialized fixturing and work holding devices, as well as a 60 ton hydraulic press and the specialized equipment that comes with it.

micro machining

Which materials do you work with in your shop?

Just about everything. Lots of plastics, PEEK, Delrin and Acrylic, aluminum, steels, stainless steels, carbon fiber, different woods, laminates, and more.

What sets Anderson Prototypes apart from the competition?

We often take on jobs that other shops won’t, due to our team’s large vision. We stand behind every piece we make and have zero returned items to date. Embodying both old-school traditions and cutting-edge technology, Anderson Prototypes believes that “Impossible is just an Opinion”. We work with a project from the very beginning to the time it is up and running at the client’s facility. We work with building very small detailed machines to unique and weird items that someone dreamed up and could not find anyone able to make. We also love to give back to the community. We have sponsored local high school and university students in competitions, and we have played a part in the Maker Community since Day One. We also made and donated a doggy wheelchair to a dog in need (YouTube), and we sponsor a local softball league.

How did you get into the entertainment/prop business?

Vancouver has a huge movie industry, and there are many people in my network that work in the industry. The need for various props, new equipment, and repairs can go up and down as movies are being filmed. The first job I did (I think), was for a movie called Space Buddies, the 4th or 5th entry in the Air Bud movie series. I made the Doggles (dog goggles), that the dog is wearing on the DVD cover. Most movies require a Non-Disclosure Agreements before any work is done, so I can’t talk about much, but I have made my impact on the screen, behind the scenes, and even live on stage. I also did a major prop for an Australian TV show that was apparently popular down under, so you never know where this work will take you!

micro machined

Who is the most famous contact that you have worked on a project with?

I have met many directors and producers of large budget films and TV shows. Unfortunately, because of the Non-Disclosure Agreements, I cannot mention any names.

Why is high-quality tool performance important to you?

I buy all my tooling from North America. I am lucky enough to have a solid carbide tooling manufacturer 5 miles from my shop, so I get quality endmills, made to order. When I need something specialized, Harvey is the only company I go to. When a tool does more than I expect, I make more money and have less stress. I count on that and become a return customer. For example, I used a .018″ Miniature End Mill (#73018-C3) on some acrylic parts I was making. There were 40 parts in total, all around the size of a stamp, with lots of tiny details, high tolerances, and very small features. I had the machine running at 15,500 RPM for 3 weeks, and I only broke one tool in that entire run. What a great tool!

What is your favorite process to work on as a machinist?

I really enjoy making something I have never worked on before, that new challenge. Often it seems that I am designing new items now more than ever. I have to do things that are not being done commercially and I stand behind it. So I might run the manual lathe, the CNC mill and then the CNC lathe on one part. I enjoy the variety.

anderson prototypes

Why is manufacturing your products in North America important to you?

American and Canadian-made products are very important to me. I purchase North American-made products like steel and aluminum, and bearings and fasteners all of kinds. I also access services locally, such as laser cutting, anodizing and powder coating, to support these local businesses. I feel its very important to the customer making the purchase that these are products my neighbors are helping to build.

If you could give one piece of advice to a new machinist ready to take the #PlungeIntoMachining, what would it be?

Take the time to take an accredited machine shop training course, like I did. It will give you all the groundwork to understand the real world of machining. I know a few fellas with small CNCs that can’t make a living because they don’t understand the depth of set-ups or work holding, for example, because they never learned from an expert. They can’t make parts fast enough, they charge 1/2 of what I do, and it takes then 3 times as long, so they simply can’t compete with me. Just be aware that it doesn’t happen overnight; I was a Journeyman Machinist for over 30 years, and still ask for help from my mentors occasionally. Oh, and find yourself a quality machine. Find a good used HAAS, or OKK, or something made in the US, UK or Europe. Your clients will respect you more and it will work longer and more accurately.

Is there anything else you would like to share with the In The Loupe community?

I am grateful for the education I have received from the many journeyman machinists, engineers, mechanics, electricians, pilots, sea captains and more who I have worked beside in my years. I am happy to share and offer problem-solving, sometimes for free, other times at consultation rates. When a young eager person asks me a question, I do the best I can to answer it in a way that benefits them long term. Sometimes they don’t like the answer, but I tell them to come back in 6 months and tell me how it went. That’s when the rubber hits the road.

anderson prototypes


Would you like to be considered for a future “Featured Customer” blog? Click here to submit your information.

Photos courtesy of Anderson Prototypes.

Optimize Roughing With Chipbreaker Tooling

Chipbreaker End Mills feature unique notch profiles, creating a serrated cutting edge. These dividers break otherwise long, stringy chips into small, easily-managed swarf that can be cleanly evacuated from the part. But why is a chipbreaker necessary for some jobs, and not others? How does the geometry of this unique tool impact its proper running parameters? In this post, we’ll answer these questions and others to discover the very real benefits of this unique cutting geometry.

How Chipbreaker Tooling Works

As a tool rotates and its cutting edge impacts a workpiece, material is sheared off from a part, creating chips. When that cutting process is interrupted, as is the case with breaks in the cutting portion of the tool, chips become smaller in length and are thus easier to evacuate. Because the chipbreakers are offset flute-to-flute, a proper, flat surface finish is achieved as each flute cleans up any excess material left behind from previously passed flutes.

Benefits of Chipbreaker Tooling

Machining Efficiency

When chips are removed from the part, they begin to pile in the machine. For extensive operations, where a great deal of material is hogged out, chip accumulation can very rapidly get in the way of the spindle or part. With larger chips, accumulation occurs much faster, leaving machinists to stop their machine regularly to remove the waste. As any machinist knows, a stopped machine equates to lost money.

Prolonged Tool Life

Inefficient chip evacuation can lead to chip recutting, or when the the tool impacts and cuts chips left behind during the machining process. This adds stresses on the tool and accelerates rate of wear on the cutting edge. Chipbreaker tooling creates small chips that are easily evacuated from a part, thus minimizing the risk of recutting.

Accelerated Running Parameters

A Harvey Performance Company Application Engineer recently observed the power of a chipbreaker tool firsthand while visiting a customer’s shop in Minnesota. The customer was roughing a great amount of 4340 Steel. Running at the parameters below, the tool was able to run uninterrupted for two hours!

Helical Part No. 33737
Material 4340 Steel
ADOC 2.545″
RDOC .125″
Speed 2,800 RPM
Feed 78 IPM
Material Removal Rate 24.8 Cubic In/Min

Chipbreaker Product Offering

Chipbreaker geometry is well suited for materials that leave a long chip. Materials that produce a powdery chip, such as graphite, should not be machined with a chipbreaker tool, as chip evacuation would not be a concern. Helical Solutions’ line of chipbreaker tooling includes a 3-flute option for aluminum and non-ferrous materials, and its reduced neck counterpart. Additionally, Helical offers a 4-flute rougher with chipbreaker geometry for high-temp alloys and titanium. Harvey Tool’s expansive product offering includes a composite cutting end mill with chipbreaker geometry.

In Summary

Chipbreaker geometry, or grooves within the cutting face of the tool, break down chips into small, manageable pieces during the machining process. This geometry can boost shop efficiency by minimizing machine downtime to clear large chips from the machining center, improve tool life by minimizing cutting forces exerted on the tool during machining, and allow for more accelerated running parameters.

Harvey Performance Hosts Local Students for Manufacturing Day Tour

Harvey Performance Company welcomed dozens of local high school students to its Gorham, ME manufacturing facility for an educational tour as part of “Manufacturing Day,” a national day of celebration of modern manufacturing meant to promote, inform, and inspire.

As part of the tour, students were led around the facility by Harvey Performance Company engineers, receiving valuable insight on how a state-of-the-art CNC grinding machine turns a carbide blank into specialty tooling.  The event concluded with a question and answer segment led by Plant Manager Adam Martin.

“It was a thrill for me to meet with the participating students, and to see just how enthusiastic they were about manufacturing,” Martin said. “The Harvey Performance team really had a great time celebrating Manufacturing Day with them.”

harvey performance company

Nationwide, more than 2,800 events took place for current and aspiring machinists as part of Manufacturing Day, held the first week of October every year. In 2016, 84 percent of participants in a Manufacturing Day event were more convinced that manufacturing provides interesting and rewarding careers, according to data from Deloitte and the Manufacturing Institute.

Harvey Performance Company remains committed to its goal of highlighting the best of the manufacturing industry via its “Plunge Into Machining” campaign.

Koenig Knives – Featured Customer

Koenig Knives is a fast-growing, Idaho-based knife manufacturer, recognized by many as one of the premier knife-making companies in the market today. Bill Koenig started the company back in 2013, using his off-days  in between his long shifts working the oil fields in North Dakota to build the business. After 3 years of exploring the craft, building a presence in the market, and saving money, Koenig was able to lease a work space, buy his first Haas machine, and start manufacturing his knives right here in America. The Koenig Knives team has now expanded to include four more employees: Krista, the Director of Operations, Cameron, the Lead Machinist, Doug in Assembly, and Todd, who works on finishing. Koenig Knives is quickly becoming known for their focus on quality, innovation, and consistency, backing all of their knives with a lifetime warranty.

We talked with both Bill and Cameron for this latest Featured Customer profile, exploring the world of CNC knifemaking, how they use High Efficiency Milling (HEM) to improve their machining efficiency, and the effect that the machining community on social media has had on their business.

koenig knives

Tell us about your business and how you got started.

Bill: Koenig Knives was started in 2013. I have always been passionate about knives, starting when I was in the Boy Scouts as a young boy. This passion turned to obsession and I went from a collector/enthusiast to a knife manufacturer in December of 2013 when we released our first batch of knives.

Originally we used an off-site manufacturer, who we worked closely with from 2013 until mid-2016. We continued to grow rapidly, and that is when I made the decision to start handling all manufacturing ourselves. We took delivery of our first machine, a Haas VF2SS, at the end of 2016. The rest is history.

What made you get into machining?

Cameron: I started as a CNC operator at an assault rifle manufacturer. After seeing raw material being machined into a beautiful, functioning gun, I decided to make machining my career and I have never looked back.

What sort of machines do you use in your shop?

Cameron: We currently have two Haas VF2SS machines and an Okamoto.

Which materials do you work with in your shop?

Cameron: We work with wide range of materials, including Grade 5 Titanium, Timascus, Damascus, Carbon Fiber, Micarta, Tool Steel , 6061 Aluminum , CTS-XHP, CTS-204P, and 416 Stainless Steel.

helical chamfer mill

What sets Koenig Knives apart from the competition?

Bill: We are often asked what category we would place ourselves in, whether it be production, custom etc. I always hesitate when answering because I can’t think of a way to categorize Koenig Knives besides “high end production with custom offerings.” We have a high end production line, but we also offer the ability to order your own customized version of one of our knives. This is something that is not too common in the industry. Quality, customer service and innovation are our main goals as a company, and we feel we have done a great job hitting on all three.

What is the most challenging part of the knife-making machining process?

Cameron: I think what makes the machining process unique with our product is the fact that we use some of the most cutting edge steel alloys for our blades. It becomes more challenging because these steel alloys are constantly advancing. Finding the perfect harmony of machining parameters for some of the relatively newer steels can be a challenge at times.

Why is high quality tool performance important to you?

Cameron: When part finishes are extremely crucial and there’s a high quantity of parts needed, having high quality tooling like Helical is essential. Helical tools help us maintain a much higher machining efficiency because of the outstanding tool life, while also achieving more aggressive run times. In addition, we are able to consistently keep high tolerances, resulting in a better final product.

koenig knives

What is your favorite process to work on as a machinist?

Cameron: I love everything about this career, except cleaning the coolant tank. I could do without that…

Koenig Knives has a great Instagram following. Tell us more about how the machinist social media community has helped grow your business.

Cameron: The machinist social media community has helped us connect with various knife makers all over the world. We learn from each other by sharing techniques and helpful tips, and we inspire each other by sharing our creations online. The machinist community on Instagram has been great – we would recommend any business, even the smallest job shops, to take a look at starting their own accounts.

Why is manufacturing your products in America important to you?

Bill: Buying American has always been very important to me for many reasons. The sense of supporting fellow American workers was instilled in me at a young age.  When I started Koenig Knives, I wanted to make sure everything from the screws to the boxes was made in the US.

koenig knives

Tell us about your favorite project that Helical helped to create.

Cameron: Machining the Arius blades (pictured above) has been my favorite on-going project. Once we switched to all Helical tools, it drastically improved our run times and blade finish, and created an incredible final product.

Have you used High Efficiency Milling techniques in your shop?

Cameron: Absolutely! We couldn’t do without HEM!

What advice do you have for other machinists who want to try High Efficiency Milling?

Cameron: Machining Advisor Pro is an absolute game changer when it comes to HEM, as well as for general machining solutions. The technical milling strategies and information that Helical makes available give machinists everything they need to be successful. When a machinist has a full understanding of what is taking place and what is needed to efficiently and correctly cut material, the sky is the limit.

If you could give one piece of advice to a new machinist ready to take the #PlungeIntoMachining, what would it be?

Cameron: With machining technology advancing at the amazing rate that it is, there is no better time to become a machinist. It is a trade that is constantly improving, and offers so many opportunities for young people.

koenig knives


Would you like to be considered for a future “Featured Customer” blog? Click here to submit your information.

Photos courtesy of Koenig Knives.

Weiss Watches – Featured Customer

Weiss Watch Company is restoring prestige to American watchmaking. They design and build timepieces with mechanical movements by hand in Los Angeles, California. Each timepiece is individually assembled in America. Their practices merge historical techniques and modern technological advances, with every process perfected by a Swiss-trained and certified American watchmaker. Weiss Watch Company strives to increase the percentage of domestic sourcing with each edition, and is the only company resurrecting industry practices that have not been active in the United States for decades.

Grant Hughson is a Manufacturing Engineer at Weiss Watch Company. Grant “lives and breathes” manufacturing, currently working in his spare time as a Manufacturing Instructor at Saddleback College. We spoke to Grant for this latest featured customer blog about the watch-making process, his experiences in the industry, and his thoughts on the state of American manufacturing.

weiss watches

What made you get into machining?

I grew up with a love for finely machined products, like watches, guns, and fishing gear. I also loved car racing, and a lot of the modifications on the cars are machined from various materials. So, from a young age, I was obsessed with the work that went into these products, and knew I wanted to be a part of the manufacturing industry.

What is your favorite part of this profession?

I love the entire manufacturing process. It always starts with a dream, or an idea. Then you take that idea and turn it into a drawing, and soon after, you’ll be modeling it. The best part is when you go to actually machine the part, and watch your original idea turn into a tangible part or product.

watchmaking

What is the most challenging part of the watch-making process?

There are a few challenging parts of the watch-making process, starting with the super-tight tolerances. Surface finish is also extremely important, and can be difficult to nail. Many surface finishes in watchmaking are visual, so roughness can be deceiving. We also were forced to design all of our workholding from scratch, as nothing currently existed in the market that would work for our machining process.

You mentioned your tight tolerances. What tolerances do you typically work in?

My tolerances are in the tenths. The holes that hold the jewels (watch bearings) are +0.0002, -0.

weiss watches

What sort of machines do you have in your shop?

We have a 3 axis vertical milling machine and a 9 axis Swiss style lathe in the shop.

What type of materials do you work in?

We work in steel, stainless steel, aluminum, brass, and titanium every day. It is a wide variety, but it keeps things interesting!

How have Harvey Tool products impacted your overall shop performance?

Harvey Tools have been great tools for me. I do a lot of prototype work, and constantly need odd sized tools or specialty profiles to finish a job. Thankfully, the Harvey Tool selection is HUGE. Somehow you guys always have what I need!

Tell us about your favorite project that Harvey Tools helped to create.

I love what I do everyday, so my favorite project is an ongoing one; making watches!

watchmaking tools

Why is high quality tool performance important to you?

It’s a must! Tool to tool accuracy and performance is vital in this business, especially with our extremely tight tolerances. High quality tools make sure that we get the same performance time after time without needing to scrap parts. This saves us valuable time and money.

What is your favorite process to work on as a machinist?

I really enjoy fixture design. Holding small parts for fixture design is an art! If it’s too tight, they’re smashed. If it’s too loose, see you later; your part is gone!

As a manufacturing engineer, I also enjoy the programming aspect of CNC machining. Being able to program the toolpaths and turn my programming skills into tangible parts is why I got into this business.

weiss watches

If you were stranded on a desert island with only one Harvey Tool or Helical tool, which would it be, and why?

It would have to be the Harvey 1/4″  30° engraving tool. I could mount it to the end of a stick. It would make for a hell of a spear!

Why is manufacturing products in America important to you?

Manufacturing products in America is a crucial part of the success and security of our business. When someone else makes your parts, its not hard for them to make a competing product. Making everything on-site keeps our proprietary information safe.

If you could give one piece of advice to a new machinist ready to take the #PlungeIntoMachining, what would it be?

Ask a lot of questions and never stop learning. It’s not easy but it’s worth it. If you consider yourself a maker or inventor, it’s the only place to be! Manufacturing is awesome, and anyone who tells you different is on the way out. Keep up the good work, and keep manufacturing your products in America!

weiss watches

Would you like to be considered for a future “Featured Customer” blog? Click here to submit your information.

Photos courtesy of Weiss Watch Company.

Introduction to High Efficiency Milling

The following is just one of several blog posts relevant to High Efficiency Milling. To achieve a full understanding of this popular machining method, view any of the additional HEM posts below!

High Speed Machining vs. HEM I How to Combat Chip Thinning I Diving into Depth of Cut I How to Avoid 4 Major Types of Tool Wear I Intro to Trochoidal Milling


High Efficiency Milling (HEM) is a strategy that is rapidly gaining popularity in the metalworking industry. Most CAM packages now offer modules to generate HEM toolpaths, each with their own proprietary name. In these packages, HEM can also be known as Dynamic Milling or High Efficiency Machining, among others. HEM can result in profound shop efficiency, extended tool life, greater performance, and cost savings. High performance end mills designed to achieve higher speeds and feeds will help machinists to reap the full benefits of this popular machining method.

High Efficiency Milling Defined

HEM is a milling technique for roughing that utilizes a lower Radial Depth of Cut (RDOC) and a higher Axial Depth of Cut (ADOC). This spreads wear evenly across the cutting edge, dissipates heat, and reduces the chance of tool failure.

This strategy differs from traditional or conventional milling, which typically calls for a higher RDOC and lower ADOC. Traditional milling causes heat concentrations in one small portion of the cutting tool, expediting the tool wear process. Further, while Traditional Milling call for more axial passes, HEM toolpaths use more passes radially.

For more information on optimizing Depth of Cut in relation to HEM, see Diving into Depth of Cut: Peripheral, Slotting & HEM Approaches.

High Efficiency Milling

Built-In CAM Applications

Machining technology has been advancing with the development of faster, more powerful machines. In order to keep up, many CAM applications have developed built-in features for HEM toolpaths, including Trochoidal Milling, a method of machining used to create a slot wider than the cutting tool’s cutting diameter.

HEM is largely based on the theory surrounding Radial Chip Thinning, or the phenomenon that occurs with varying RDOC, and relates to the chip thickness and feed per tooth. HEM adjusts parameters to maintain a constant load on the tool through the entire roughing operation, resulting in more aggressive material removal rates (MRR). In this way, HEM differs from other high performance toolpaths, which involve different methods for achieving significant MRR.

Virtually any CNC machine can perform HEM – the key is a fast CNC controller. When converting from a regular program to HEM, about 20 lines of HEM code will be written for every line of regular code. A fast processor is needed to look ahead for the code, and keep up with the operation. In addition, advanced CAM software that intelligently manages tool load by adjusting the IPT and RDOC is also needed.

HEM Case Studies

The following example shows the result a machinist had when using a Helical Solutions HEV-5 tool to perform an HEM operation in 17-4PH stainless steel. While performing HEM, this ½” diameter, 5-flute end mill engaged the part just 12% radially, but 100% axially. This machinist was able to reduce tool wear and was able to complete 40 parts with a single tool, versus only 15 with a traditional roughing toolpath.

The effect of HEM on a roughing application can also be seen in the case study below. While machining 6061 aluminum with Helical’s H45AL-C-3, a 1/2″, 3-flute rougher, this machinist was able to finish a part in 3 minutes, versus 11 minutes with a traditional roughing toolpath. One tool was able to make 900 parts with HEM, a boost of more than 150% over the traditional method.

Importance of Tooling to HEM

Generally speaking, HEM is a matter of running the tool – not the tool itself. Virtually every tool can perform HEM, but using tooling built to withstand the rigors of HEM will result in greater success. While you can run a marathon in any type of shoes, you’d likely get the best results and performance from running shoes.

HEM is often regarded as a machining method for larger diameter tooling because of the aggressive MRR of the operation and the fragility of tooling under 1/8” in size. However, miniature tooling can be used to achieve HEM, too.

Using miniature tooling for HEM can create additional challenges that must be understood prior to beginning your operation.

Best Tools for HEM:

  • High flute count for increased MRR.
  • Large core diameter for added strength.
  • Tool coating optimized for the workpiece material for increased lubricity.
  • Variable Pitch/Variable Helix design for reduced harmonics.

Key Takeaways

HEM is a machining operation which continues to grow in popularity in shops worldwide. A milling technique for roughing that utilizes a lower RDOC and higher ADOC than traditional milling, HEM distributes wear evenly across the cutting edge of a tool, reducing heat concentrations and slowing the rate of tool wear. This is especially true in tooling best suited to promote the benefits of HEM.

Reducing Tool Runout

Tool runout is a given in any machine shop, and can never be 100% avoided. Thus, it is important to establish an acceptable level of runout for any project, and stay within that range to optimize productivity and prolong tool life. Smaller runout levels are always better, but choice of machine and tool holder, stick-out, tool reach, and many other factors all have an influence on the amount of runout in every setup.

Defining Tool Runout

Tool runout is the measurement of how far a cutting tool, holder, or spindle rotates off of its true axis. This can be seen in low quality end mills where the cutting diameter is true to size when measured while stationary, but measures above tolerance while rotating.

The first step to minimizing runout is understanding what individual factors cause runout in every machine setup. Runout is seen in the accuracy of every cutting tool, collet, tool holder, and spindle. Every added connection between a machine and the workpiece it is cutting will introduce a higher level of runout. Each increase can add to the total runout further and further. Steps should be taken with every piece of tooling and equipment to minimize runout for best performance, increased tool life, and quality finished products.

Measuring Runout

Determining the runout of your system is the first step towards finding how to combat it. Runout is measured using an indicator that measures the variation of a tool’s diameter as it rotates. This is done with either a dial/probe indicator or a laser measuring device. While most dial indicators are both portable and easy to use, they are not as accurate as the available laser indicators, and can also make a runout measurement worse by pushing on a tool. This is mostly a concern for miniature and micro-tooling, where lasers should be strictly used due to the tool’s fragile nature.  Most end mill manufacturers recommend using a laser runout indicator in place of a dial indicator wherever possible.

Z-Mike Laser

Z-Mike laser measurement devices are common instruments used to measure levels of tool runout.

Runout should be measured at the point where a tool will be cutting, typically at the end of the tools, or along a portion of the length of cut. A dial indicator may not be plausible in these instances due to the inconsistent shape of a tool’s flutes. Laser measuring devices offer another advantage due to this fact.

High Quality Tools

The amount of runout in each component of a system, as-manufactured, often has a significant impact on the total runout of a given setup. Cutting tools all have a restriction on maximum runout allowed when manufactured, and some can have allowances of .0002” or less. This is often the value that should be strived for in a complete system as well. For miniature tooling down to .001” diameter, this measurement will have to be held to an even smaller value. As the ratio of tool runout to tool diameter becomes larger, threats of tool failure increase. As stated earlier, starting with a tool that has minimal runout is pivotal in keeping the total runout of a system to a minimum. This is runout that cannot be avoided.

Precision Tool Holders

The next step to minimizing runout is ensuring that you are using a high quality, precision tool holder. These often come in the form of shrink-fit, or press-fit tool holders offering accurate and precise tool rotation.  Uniform pressure around the entire circumference of a shank is essential for reducing runout. Set screw based holders should be avoided, as they push the tool off-center with their uneven holding pressure.  Collet-based tool holders also often introduce an extra amount of runout due to their additional components. Each added connection in a tool holding system allows more methods of runout to appear. Shrink-fit and press-fit tool holders are inherently better at minimizing runout due to their fewer components.

tool runout

Included in your tool holding considerations should be machine tool cleanliness. Often, chips can become lodged in the spindle, and cause an obstruction between two high-precision surfaces in the system. Ensuring that your tool holder and spindle are clean and free of chips and debris is paramount when setting up for every job.

Shank Modifications

Apart from equipment itself, many other factors can contribute to an increasing amount of tool runout. These can include how long a tool is, how rigid a machine setup is, and how far a tool is hanging out of its holder.  Shank modifications, along with their methods of tool holding can have a large impact. Often thought of as an older, obsolete technology, Weldon flats are found guilty of adding large amounts of runout in many shops. While many shops still use Weldon flats to ensure a secure grip on their tools, having a set screw pushing a tool to one side can push it off center, yielding very high levels of runout. Haimer Safe Lock™ is another option increasing in popularity that is a much higher performance holding technology. The Safe-Lock™ system is designed with the same tolerances as shrink fit and other high precision tool holders. It is able to minimize runout, while firmly holding a tool in place with no chance of pull-out.

haimer safe lock

The Haimer Safe-Lock™ system is one option to greatly reduce tool runout.

Runout will never be completely eliminated from a machining system. However, steps can (and should) be taken to keep it to a minimum using every method possible. Keeping a tool running true will extend tool life, increase performance, and ultimately save your shop time and money. Runout is a common concern in the metalworking industry, but it is often overlooked when it could be main issue causing part rejections and unacceptable results. Every piece of a machine tool plays a part in the resultant runout, and none should be overlooked.

Most Common Methods of Tool Entry

Tool entry is pivotal to machining success, as it’s one of the most punishing operations for a cutter. Entering a part in a way that’s not ideal for the tool or operation could lead to a damaged part or exhausted shop resources. Below, we’ll explore the most common part entry methods, as well as tips for how to perform them successfully.


Pre-Drilled Hole

Pre-drilling a hole to full pocket depth (and 5-10% larger than the end mill diameter) is the safest practice of dropping your end mill into a pocket. This method ensures the least amount of end work abuse and premature tool wear.

tool entry predrill

 


Helical Interpolation

Helical Interpolation is a very common and safe practice of tool entry with ferrous materials. Employing corner radius end mills during this operation will decrease tool wear and lessen corner breakdown. With this method, use a programmed helix diameter of greater than 110-120% of the cutter diameter.

helical interpolation

 


Ramping-In

This type of operation can be very successful, but institutes many different torsional forces the cutter must withstand. A strong core is key for this method, as is room for proper chip evacuation. Using tools with a corner radius, which strengthen its cutting portion, will help.

ramping

Suggested Starting Ramp Angles:

Hard/Ferrous Materials: 1°-3°

Soft/Non-Ferrous Materials: 3°-10°

For more information on this popular tool entry method, see Ramping to Success.


Arcing

This method of tool entry is similar to ramping in both method and benefit. However, while ramping enters the part from the top, arcing does so from the side. The end mill follows a curved tool path, or arc, when milling, this gradually increasing the load on the tool as it enters the part. Additionally, the load put on the tool decreases as it exits the part, helping to avoid shock loading and tool breakage.


Straight Plunge

This is a common, yet often problematic method of entering a part. A straight plunge into a part can easily lead to tool breakage. If opting for this machining method, however, certain criteria must be met for best chances of machining success. The tool must be center cutting, as end milling incorporates a flat entry point making chip evacuation extremely difficult. Drill bits are intended for straight plunging, however, and should be used for this type of operation.

tool entry

 


Straight Tool Entry

Straight entry into the part takes a toll on the cutter, as does a straight plunge. Until the cutter is fully engaged, the feed rate upon entry is recommended to be reduced by at least 50% during this operation.

tool entry

 


Roll-In Tool Entry

Rolling into the cut ensures a cutter to work its way to full engagement and naturally acquire proper chip thickness. The feed rate in this scenario should be reduced by 50%.

tool entry

 

Magnuson Superchargers – Featured Customer

Magnuson Superchargers is a manufacturer of aftermarket and OEM (Original Equipment Manufacturer) supercharger systems for the automotive industry, located in Ventura, California. Started by industry legend Jerry Magnuson, Magnuson Superchargers has quickly grown into one of the most respected brands in the automotive industry. Magnuson creates products for various brands, including GM, Mopar, Ford, AUDI, Mercedes-Benz, Lexus, Toyota, and Jeep. Magnuson Superchargers are most commonly found in “hot rods,” everyday vehicles, off-road vehicles, and vehicles purpose built for competitive racing, as they are used to significantly yet reliably increase horsepower.

The Magnuson Superchargers team of technicians combine modern and time-tested prototyping and fabrication techniques to construct each component to exact specifications and the highest quality. Magnuson has a complete machine shop in house for fabrication of new prototype system components. This allows them to operate efficiently with short runs and high volume production.

magnuson superchargers

Hubert Gromek, Magnuson Superchargers’ Machine Shop Manager, is a 15-year veteran of the industry. We spoke with Hubert about his experiences building a career in the manufacturing industry, his advice for young machinists, and the way he and his team use both Harvey Tool and Helical Solutions tools in their machine shop every day.


Tell us a little bit about yourself.

I started with Magnuson Superchargers 15-plus years ago as a young kid who didn’t know anything about machining at all. Being a major car guy and drag racer, working for a company that makes superchargers was a perfect fit for me.  I started by deburring and washing parts and worked my way up to operating our Fadal Vertical Mills.

From there I started to get the concept of what it actually takes to machine things and started learning how to do all the setups; I even started making my own fixtures here and there. After a couple of years of being the setup guy for our shop, I started looking into the programming aspect of the job and that really grabbed my interest right away. It’s one thing to run and set up machines with other people’s programs and instruction, but it’s a whole new world when you have to do the entire job from scratch on your own.

magnuson superchargers

After a couple of years of being the Lead Setup Programmer here at our shop, I was given the opportunity to be the Machine Shop Manager. I was very honored that the owner of such a big and great company thought I had what it takes to run the whole shop. Let me tell you, when you are responsible for everything that goes on in a machine shop, it really opens your eyes to how much every little thing matters. The one thing I learned very quickly is how important it is to have the right team in your shop to support you and reach the goals that are set. It doesn’t matter how great a manager or programmer you are, if you don’t have the right team of machinists in your shop, you are setting yourself up for failure. After many years of trying, I think I have finally found that team that I’ve been looking for.

What made you get into machining?

It was when I first saw a raw piece of material (billet aluminum) become a billet bracket for a hot rod my boss was working on. I thought that was the coolest thing ever. You start with nothing and the finished product was a work of art to me. I knew right then that I wanted to do that someday.

What is your greatest challenge as a machinist?

This is a two-part answer. First, it is finding the right core team that you can trust and not have to worry about what they are doing. My current team is comprised of experienced and disciplined machinists and they know what needs to get done. I don’t have to watch over them, I just try to guide them and teach them everything that I have learned over the years.

The second part has always been fixture design. I am always learning how to make better, more user-friendly fixtures to help speed up production but still maintain very high part quality.

magnuson superchargers

What is your favorite part of this profession?

I really love the fact that I learn something new every day. It doesn’t matter how much you think you know, there is always a job that will test your ability as a machinist.

What made you decide to use Harvey Tool and Helical products?

Actually I have a great local tool supplier that I deal with all the time. His name is Mike Baldino over at PM Industrial, and he is the one who first introduced me to both of these products. We make tiny Dovetail O-Ring grooves in a lot of our parts and I couldn’t find a tool that would do the job like I wanted it to. Mike recommended the Harvey Tool .135″ Dovetail Cutter and I haven’t used anything else since. As for the Helical End Mills, since 98% of our jobs are in aluminum, Mike also recommended I try these new (at the time) Zplus coated Helical End Mills. Just like the Harvey Tool Dovetail Cutter, I haven’t used anything else since I found out how amazing these cutters worked for us.

magnuson superchargers

Why is high quality tool performance important to your team at Magnuson Superchargers?

We work with a lot of castings here at Magnuson Superchargers, and even though they are aluminum, they can be very abrasive. Because of this, tool life and part finishes are very important to us. The Helical End Mills hold up very well to cast and billet materials and the Harvey Tool Dovetail Cutters are the only thing that works for us.

Tell us about your favorite projects that Harvey Tool or Helical Solutions tools helped you create.

We make most of our casting tooling in-house, which includes master patterns and core boxes, usually in 6061 Billet Aluminum. The Helical Zplus coated End Mills are amazing for doing these jobs. Using the dynamic toolpaths and utilizing the entire flute length is great. As for the Harvey Tool Dovetail Cutters, I haven’t used anything that works better than these. Every project has become easier with the use of both Harvey Tool and Helical Solutions tools.

magnuson superchargers

A 2016 Chevrolet Camaro loaded with the TVS2300 supercharger at the track.

One of our most exciting projects is our new TVS2300 supercharger that we built for our 2016 Chevrolet Camaro. We took a completely stock engine and transmission, and with just our supercharger and a couple of modifications it was able to run a 9 second 1/4 mile drag race. This was very impressive and has made a huge impact in the automotive industry. We are very excited about this kit and the potential it has in the market.

We have also been working on the biggest supercharger that our company has ever made, the new TVS2650. We are very proud of the all the R&D work that has gone into this kit and we are seeing some incredible horsepower numbers from these units. We displayed this at last year’s Specialty Equipment Market Association (SEMA) show in Las Vegas. We are still in the prototype stages of this project but will have production units coming very soon.

magnuson superchargers

A prototype of the new TVS2650 supercharger, the largest ever built by Magnuson.

Would you recommend that young people take the #PlungeIntoMachining and start a career as a machinist?

I personally would recommend a career in machining to anyone who has an interest in how things are made. I believe it is a great career choice. There are always going to be parts that have to get made somehow, so there is no shortage of open jobs available in the industry. I have a 4 year old son and as soon as he is old enough, I will teach him everything I know about this profession. If he chooses not to go that route, that is completely okay, but at least he will know what it takes to make something from scratch.

If you could give one piece of advice to a new machinist, what would it be?

Learn the basics. Start with a manual mill or lathe and get some experience with how it feels to cut something. Lots of people start on a CNC as an operator and call themselves “machinists.” It took me 5 years before my boss officially called me a machinist! Trust me, it feels really good when your boss hands you a print or CAD model and says “make this,” and you come back with a perfect part that you were able to make yourself.

magnuson superchargers

The Magnuson Superchargers machine shop team. From left: John, Jesus, Jun, Miguel, Jesse, Kenton, and Armando.

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Photos courtesy of Magnuson Superchargers