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Chipbreakers vs. Knuckle Rougher End Mills

Knuckle Roughers and Chipbreakers are common profiles found on roughing end mills that, while fairly similar in appearance, actually serve different functions. Chipbreakers refer to the notches along the cutting edge of a tool that work to break up chips to prevent common evacuation mishaps. Knuckle Roughers refer to the serrated cutting edge of a tool, which works to enhance cutting action for an overall smoother operation.

Determining the appropriate style of tool is a very important first step to a successful roughing application.

Understanding the Two Styles

Chipbreaker End Mills

To aid chip evacuation, Chipbreaker End Mills feature a notched profile along the cutting edge that break down long chips into smaller, more manageable pieces. These tools are often utilized in aluminum jobs, as long, stringy chips are common with that material.

Each notch is offset flute-to-flute to enhance the surface finish on the part. This works by ensuring that as each flute rotates and impacts a part, following flutes work to clean up any marks or extra material that was left behind by the first pass. This leaves a semi-finished surface on your part.

In addition to improving chip control and reducing cutting resistance, these tools also help in decreasing heat load within the chips. This delays tool wear along the cutting edge and improves cutting performance. Not only are these tools great for hogging out a great deal of material, but they can be utilized in a wide array of jobs – from aluminum to steels. Further, a machinist can take full advantage of the unique benefits this tool possesses by utilizing High Efficiency Milling toolpaths, meant to promote efficiency and boost tool life.

Knuckle Roughers

Knuckle Rougher End Mills have a serrated cutting edge that generates significantly smaller chips than a standard end mill cutting edge. This allows for smoother machining and a more efficient metal removal process, similar to Chipbreaker End Mills. However, the serrations chop the chips down to much finer sizes, which allows more chips into the flutes during the evacuation process without any packing occurring.

Designed for steels, Knuckle Rougher End Mills are built to withstand harder materials and feature a large core. Because of this, these tools are great for roughing out a lot of material. However, due to the profile on the cutting edge, tracks along the wall can sometimes be left on a part. If finish is a concern, be sure to come in with a finishing tool after the roughing operation. Knuckle Roughers have proven the ability to run at higher chip loads, compared to similar end mills, which makes this a highly desired style for roughing. Further, this style of rougher causes a lot of heat and friction within the chips, so it’s important to run flood coolant when running this tool.

Key Differences Between Knuckle Roughers & Chipbreakers

While the two geometries offer similar benefits, it’s important to understand the distinct differences between them. Chipbreakers feature offset notches, which help to leave an acceptable finish on the walls of a part. Simply, the material left on an initial flute pass is removed by subsequent passes. A Knuckle Rougher does not feature this offset geometry, which can leave track marks on your part. Where part finish is of upmost importance, utilize a Knuckle Rougher to first hog out a great deal of steel, and work a final pass with a Finishing End Mill.

A unique benefit of Knuckle Roughers is the grind they possess – a cylindrical grind, compared to a relieved grind of a Chipbreaker End Mill. Because of this, Knuckle Roughers are easier to resharpen. Therefore, instead of buying a new tool, resharpening this profile is often a cheaper alternative.

Nueva Precision – Featured Customer

When it comes to CNC manufacturing services and product development solutions in the Denver, Colorado area, Eddie Casanueva has quickly made a name for himself with his company, Nueva Precision. Eddie has more than 22 years of manufacturing experience and 19 years of business experience, which he uses to help small businesses and entrepreneurs who are looking for product support and development.

Eddie was able to take time out of his busy schedule to talk with us for this Featured Customer post. We covered topics like Eddie’s incredible training and introduction to manufacturing, his experiences using reduced neck end mills, and his suggestions for must-have equipment in any CNC machine shop.

Thanks for taking the time to talk to us for this Featured Customer post. To get started, tell us a little bit about the history behind Nueva Precision and what sort of products you typically manufacture.

Nueva Precision was first incorporated at the end of 2016. Within three months, I was making chips on my own, largely doing prototype work.

I had recently sold my share in another company I co-founded and used that money to move into a larger home in the Denver area that could accommodate a machine shop business. We were lucky enough to find a home with some acreage and an existing oversized garage which was perfect for a shop. Now that I had the building, I had to do things like get the electrical and HVAC up to spec. It required having the city run a stronger electrical line to the building I would use as my shop, but once that was all figured out, we were ready to make some chips.

Nueva Precision

I started by buying a used Haas mill and a used Haas lathe. People initially reached out to me for work because of my quick delivery times. I was able to turn around parts in just a week or two since the business was new. However, within a month of operating those machines, I was already at max capacity with my current equipment. Unfortunately, my lead times had increased to a more standard 4-6 weeks due to the sheer amount of work I was getting. For the rest of 2017, I stuck with my original equipment and just did the best I could to keep up.

nueva precision

Do you have any future plans to expand your shop and capabilities further?

I do! In early 2018 I brought in a brand new VM3 Haas Mill to keep up with demand, but I was curious about how much more revenue that would create. I expected to see a 20-30% increase in revenue, but having another machine ended up doubling my revenue. Luckily my strong relationships with my customers helped me grow the business even as my lead times increased. With that in mind, I just ordered another Haas VM2 at the end of 2018 and am excited to take full advantage of that.

How has your family reacted to you running a business out of your home?

My family has been extremely supportive throughout the whole process. My wife Leandra in particular helps out a lot. She was a teacher for 19 years, but resigned from that profession to work on Nueva Precision. She has started to help out on the business side of things and has also started to help run machines and make parts. My oldest son Jaden (16) is interested in manufacturing and he has started working and making simple parts for us when he is available. All in all, we have a pretty good thing going here.

Eddie and Leandra Nueva Precision

Eddie and Leandra

Jaden nueva precision

Jaden working on parts

How did you first get involved in CNC machining and advanced manufacturing?

I am essentially self-taught in CNC machining. I got started in engineering and manufacturing as a student at the New Jersey Institute of Technology (NJIT) in the Mechanical Engineering program. It was a state school, so tuition costs weren’t bad but I still needed to support myself. I was going to school during the day and pumping gas at night to pay the bills. In my second year in school I came across an opportunity to work at an on-campus research center for manufacturing systems. It was funded by the state of New Jersey to help promote New Jersey industry. The job didn’t have much to do with my curriculum, but they supported some campus research and worked closely with the college on various projects.

The research center had all the workings of a machine shop. There were CNC mills, lathes, injection molding machines, and more. It just looked awesome. I managed to get hired for a job at minimum wage sweeping the shop floor and helping out where I could.

As a curious student, I would ask a million questions of all the machinists and try to do more and more than the usual student employee. John – a talented toolmaker and experienced machinist – took me under his wing and taught me lots of stuff about machining. I started buying tools and building out my toolbox with him for a while, absorbing everything that I could. Next thing I know, they’re handing me prints and I am making parts. A few months down the road the machinists started teaching me programming on a Mazak controller. This went on for a year or so and I just soaked it all in.

nueva precision

Sounds like great experience! Where did you land your first full-time position in manufacturing?

I actually landed my first full-time job at the same manufacturing research center. The center had a CNC machinist programmer resign at the facility, so there was a job opening posted. I went to the director of the center and said I was interested in the position. I knew I had to work a lot to pay my tuition, and if I worked for the university I could get my tuition paid for while also making some real money. The director recommended me for the position, so I interviewed and landed the job. All of a sudden, I had benefits, vacation, real responsibilities, and full-time pay. I flipped my schedule around so I could go to school during nights and work during the day.

I learned so much about machining in my first job because of the unique situation I was in. Companies like Blaser Swisslube, Kennametal, and GibbsCAM were supplying us with product and support to work on process improvements for large New Jersey corporations like BF Goodrich Aerospace, US Can, etc. It progressed to the point where GibbsCAM was actually sending me to seminars to train me on different industry topics to further my education and improve the reports we were outputting.

nueva precision

I was in an amazing position to get all this training and I learned so much in the next 4-5 years. We had equipment like a Fadal 5-Axis CNC Machine and other high tech machines at my disposal, which were very hard to find at the time (mid-1990s). Nobody outside of the most elite machine shops were working in 5-axis, so I had a head start because of this unique job experience.

I actually never finished my degree and instead dove head first into manufacturing. I started my own business on the side and kept working at the research center until 2001 when I left to focus full-time on my new business, Spidertrax Offroad.

Can you tell us more about your experience with Spidertrax Offroad?

Spidertrax Offroad is a manufacturer of drivetrain parts for off-roading vehicles. I started Spidertrax with a partner whom I met in college. The company actually started making our first parts at the research center I was employed at. I asked my boss if I could start making parts off the clock on my own time, and he agreed to let me use the shop. This would have been around 1998, and by 2001 I was ready to take off on my own. My partner and I built that company up to 20 employees, and we were (and they still are) a well-respected brand in the off-roading community.

The hardest part about operating my own business and watching it grow was losing the ability to get out in the shop and actually do what I love, which is making parts. As the business grew, I had to take on more responsibility as a “business man,” and let go of many of the things I enjoyed doing as a machinist. I was very proud of what we had built, but I really wanted to get back to basics. So, in early 2017 I sold my half of Spidertrax Offroad to my partner and took that money to buy the new house and open Nueva Precision, Inc.

What sort of machines and CAM software do you have in your new shop?

Right now for CNC machines I have a 2018 Haas VM3, a 2018 Hass VM2, a 2012 Haas VF2, and a 2012 Haas TL2. I also have an engine lathe, a Bridgeport knee mill, Kaeser screw compressor, which I absolutely love, and a couple of Jet saws.

For software, I still use GibbsCAM. I have been using GibbsCAM since 1996 and have had countless hours of training and experience using it, so I think I’m a lifer.

haas vf2

Outside of tooling, what are some key components of your machining setup that you would recommend to others?

I started Nueva Precision without any sort of probing system in place, and using an umbrella style tool changer. I found out quickly that my time, especially being alone, is worth a lot. I highly recommend getting a solid probing system as well as a side mount tool changer. I added all of that to my VM3 and the effect was immediately noticeable. It is so much more efficient and faster.

Keeping software up-to-date is also key. It can be expensive, but it speaks for itself in just a few months. Any time I invest in technology, it seems to pay off pretty quick.

5th axis workholding

I also feel strongly about having solid workholding. I have a couple of the 5th Axis self-centering vises which are great, and a handful of Kurt vises, as well. I am also a big fan of the MMM-USA guys and their vise jaws and handles. For my shop, flexibility is key because I never know what can come through the door. I don’t do a lot of production work and spend much more time on prototype work, so flexibility is key. Having good quality workholding that I don’t need to worry about lets me swap parts in and out with ease.

As for tool holding, I ran into an issue last year where I was starting to see a lot of tool pullout and was scrapping too many parts as a result of aggressive roughing. I had to find a better solution, and I came across the REGO-FIX PowRgrip system. It might seem expensive compared to other simpler tool holder, but I think the upfront investment isn’t too bad considering the other options in that space. Again, I invested in technology, and immediately saw better results. I currently use the PowRgrip for finishing passes where I need good runout and heavy roughing where there is the highest risk of tool pullout.

REGO powRgrip

You use a lot of Helical’s Reduced Neck end mills. What are some tips or tricks you have learned by using these tools that you could share with others?

My experience with these tools is really new, but I find myself using more and more of them these days. In the beginning, I was afraid of end mills with a longer length of cut singing like crazy in the machine. I started experimenting with the reduced neck tools from Helical and was blown away by the rigidity. The tool pressure remains consistent throughout the part, so you will get the same great results on the top of the part as on the bottom.

I don’t know how many people are currently using them but it makes so much stuff possible. I have gone as large as ¾” diameter with the 5” reach and have never had an issue. Maintaining the low levels of runout is definitely key with these tools, which again comes back to having solid toolholding. Now that I have the REGO-FIX system, I am getting much better runout and plan to start pushing the reduced neck tools even harder.

helical reduced neck end mill

Most of my reduced neck end mills are the standard style, but the chipbreaker with the reduced neck has been a powerhouse for me as well. No matter what I tried with Helical’s reduced neck tooling, I have had success, so I would recommend the entire line if the situation calls for it. Just be careful with runout and make sure to double check your clearance!

What are some of your key Helical products that you use on a daily basis?

My main workhorse is Helical EDP 29422 – the ½” 45 Degree Chipbreaker for Aluminum. I swear I use that tool every single day across all of my machines. That tool is gold for me; it is night and day compared to standard roughers. It has a long enough flute length to be versatile or aggressive, depending on the situation. It is just a great tool. You will need a good holder for sure to keep it from pulling out when you get aggressive, but again my new software and tool holding helps with that.

helical solutions

Outside of performance, I love getting the smaller chips that the chipbreaker tools create. It is so much easier to clean a machine with small chips than long, stringy ones, which saves me time. I do all my roughing with chipbreakers. If you are making stringy chips while running HEM toolpaths, they can be a major pain to deal with.

My customers love the finish that Helical gives me as well. The wiper flat on the bottom of the H40ALV-3 end mill stands out as one of my favorite features on any of my tools. That tool gets me compliments on the floor finishes of pockets and enclosures all the time. Across the board, tool life and finish has been awesome with my Helical end mills. I currently use the Zplus coating for all my aluminum tools and have no complaints.

part finish

This summer I had the privilege of working on some aerospace parts that will be going up into space!  Most all parts were being machined from pre-hardened stainless steels and exotic alloys.  The Helical 5-flute and 7-flute endmills with the Aplus coating proved to be great tools to have in the arsenal.

What are your “go-to” Harvey Tool products?

For Harvey Tool, I use a lot of the full radius Keyseat Cutters to surface mill areas you can’t get to with a ball nose end mill. This saves me valuable time because I can avoid flipping the part to surface mill both sides by doing it all in one operation with the Keyseat Cutter.

keyseat cutter

Outside of the keyseats, I use a lot of miniature end mills with reduced shanks and chamfers mills in a variety of angles. I also use lollipops (undercutting end mills) to surface mill parts with hard-to-reach holes.

Overall, being able to look through a single catalog and find tons of options for neck diameters and cutter diameters is what sells me on the Harvey Tool product. It is really neat to have all those different tools available to me in one place – it’s a great catalog.


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Master Machine Manufacturing – Featured Customer

Master Machine Manufacturing, or MMM USA, is a family-owned and operated machine shop based out of Tulsa, Oklahoma. Master Machine is a rapidly expanding company which has seen serious growth as both a job shop and as an OEM Manufacturer of their own Quick Vise Handles and Piranha Jaws for CNC machinists.

Brothers Geordan and Nace Roberts, along with their mother, Sherry Roberts, are the owners of Master Machine Manufacturing. With Geordan and Nace, we dove into topics like having a growth mindset, working smarter instead of harder, and expanding a “job shop” business while also creating and manufacturing their own OEM products.

Tell us a little about Master Machine’s history and the type of work that your company does.

Geordan: Master Machine has been in business since 1981. Our father, George Roberts, started the business. At the beginning it was a pretty typical manual machine shop operating primarily as a job shop. As Nace and I got older, Dad introduced us to the business and we started working there part-time, eventually transitioning into full-time employees. In 1996, we transitioned to high precision machining with our first CNC machine – a Haas VF1, and we kept adding new CNC machines from there.

Nace and I took over in 2013 after our Dad passed. We had to make the transition from managers and shop foreman to owners and dealing with customers. We now own and operate the business with our mother, Sherry Roberts.

master machine

Geordan, Nace, Sherry, and the rest of the MMM USA team at IMTS with Mark Terryberry from Haas Automation

At its core, Master Machine is a job shop that does a lot of high precision machining. We work on things like lab test equipment, parts for the aerospace industry, and a lot of parts for the oil and gas industry. More medical jobs and odd things like parts for off-road racing have started to come in recently as well. One cool thing about us is that we have the unique ability to operate as a job shop, but also to design and manufacture our own products. Many of your readers have probably seen some of our vise handles and jaws in use online, especially on Instagram.

Your MMM USA Jaws and Vise Handles have become extremely popular in the CNC machining community. Where did you get the idea for that product?

Geordan: We had been using other brands of vise handles and jaws for a long time and got tired of buying products that were cheap and didn’t work well. We had this idea for a while, so in 2013 when things started to slow down a little bit, we had an opportunity to spend some time and design our own products. It was just about 2 years ago that we designed our first vise handle and Piranha Jaws. After using social media, showing them off at IMTS and other Industrial Trade Shows, they really started to take off. Our vise handles and jaws have really started to become a business of their own over the past couple of years.

vise handle

Can you breakdown the shop for us? What are you working with in terms of shop size, machine capabilities, and software?

Nace: We operate as a 100% debt-free company, so we grow as we need to. We have been at our current location for 10 years with 5-7 different additions along the way. Our shop is now spread across 10,300 square feet.

We currently have 18 CNC milling machines, including our original machine, the 1996 Haas VF1. We have been growing very fast over the past 10 years. From 2004-2007, we only had 3 CNC mills, and we have acquired the other 15 machines all in the last decade. We like buying from companies that make their products right here in the USA, so we have grown our shop through the Haas line of machines. Almost everything we own here is made by Haas Automation. In fact, our Haas VF4 and our 5-axis Haas UMC750 are some of our biggest mills in the shop right now.

Geordan: We also have other capabilities in the shop. We can do welding, painting, surface grinding, and we have a nice setup of bar feeders and lathes. For software, we use a lot of BOBCAD V31 for our 4th and 5th axis mill programming and all of our lathe programming, Nace uses a lot of Autodesk Fusion 360 for the mill side of things.

For inspection, we have many inspection tools, including a Fowler Z-Cat CMM that can measure down to +/- .0002″ for our most high precision jobs.

How did you guys first get involved in manufacturing?

Geordan: I started machining with my Dad at age 13, and got into it full-time after high school, but was not yet fully committed. At this point, I learned manual and CNC machining entirely through working with my Dad and my Uncle.  It wasn’t until my Uncle, the main machinist in our shop, decided to split off and start his own shop that I was faced with a more urgent need to commit to the family business. So I decided to make manufacturing a full time career move and started learning fixturing, programming, and everything I needed to know to be successful. We still have a great relationship with my uncle and his shop and I wouldn’t be where I am today without him stepping out on his own.

Nace: I didn’t know what I wanted to do with my life. I just knew I wanted to make money, and a lot of money. I was actually in college for radiology and physical therapy, but I didn’t like the layout of the career path. I could not convince myself to wait to start making real money until I had finished a long education and received a license 6-8 years down the road.

Instead of physical therapy and radiology, I started taking more computer engineering courses and learned a lot about programming and technology. After my uncle left, I told my Dad I would like to be a bigger part of the business and take what I knew from my computer programming classes and apply it to the shop. Within a year I had gone from never running a CNC to fully doing everything on the machine. My computer programming skills definitely helped me make the transition into CNC machining and programming.

master machine

As a second generation owner of a family business, how do you stick to those family values while also rapidly expanding the business?

Nace: We have grown a lot with our systems and technology, but our culture has also changed since we took over. We educated ourselves on workplace culture and maintaining a positive work environment. When we were kids, Dad worked probably 100 hours a week and we were always fortunate that he was able to provide us with food, clothes, and a roof over our heads. But no matter how hard he worked, he can’t replace the time with us that was spent working.

One of the major improvements we focused on was trying to maintain repeatability. Everything in the shop is labeled in boxes and readily available for our employees. Ultimately, we want to do everything we can to make it easy as possible for our employees. We want to work smarter, not harder, so there is more time for our employees to spend with family and not spend their lives in the shop.

As owners, we often need to work odd hours of the day to maintain the business, but we do it in a way that makes sure we have our family time. There are many times where we will go home, have dinner and hang out with the family, and wait until they are all sleeping to go back to work until 2 or 3 a.m.. We will get back home later that morning to sleep a little and have breakfast with the family and send them on their way before heading back in to the shop.

Working with family, we have to remind ourselves that business is business, and outside of business it is all about family. It can be tough to differentiate those two, but you have to. We went to business counseling and learned how to respect family members and build up the team while also making tough business decisions. We have our tough moments at the shop, but at the end of the day this is still your family. You can’t carry any frustration with other family members outside of those shop doors and into the home.

mmm usa piranha jaws

What are some other things you have done to maintain your “Work Smarter, Not Harder” mantra?

Geordan: One of the first things we did was look into getting more tooling and better tooling. We paid more for tools that can push harder and faster, and last longer. When Dad ran the shop, he would just buy whatever he thought we could afford and still get the job done. Now as CNC technology and advanced CAM systems have improved, the need for quality tooling is extremely important. Finding the best and most reliable tools helped take our shop to the next level and that is where Harvey Tool and Helical come into play.

Nace: We like to be the “purple cow” of the industry, differentiating ourselves in any way that we can. We strive to maintain a certain level of quality across our website, our Instagram page, our products, and the entire business as a whole. We are proud to support products made in the USA and keep supporting American manufacturing to help keep the business thriving in our shop and others. We are always happy to support companies like Haas, Harvey Tool, Helical, and many others who are doing it all right here in the USA.

What are some of your “go-to” Harvey Tool and Helical products?

Geordan: The Helical Chipbreaker End Mill for Aluminum is key for making our vise handles. We use the ½” end mill and run it at 10k RPM, 300 IPM with a .700” DOC and 40% stepover. We can push those tools harder than others while also maintaining our product’s quality. We also rely heavily on Helical’s HEV-5 for our steel applications.

One of our favorite and most-used tools is the Harvey Tool 90 Degree Helically Fluted Chamfer Mill. We use the 3-flute style on everything that isn’t Aluminum because we can simply push it faster and harder than anything else that we have tried.

master machine

Nace: We actually keep a ton of other Harvey Tool and Helical products in our Autocrib. It made sense for us to get an inventory system, and we got a great deal on a system during the recession. Industrial Mill & Maintenance Supply got us hooked up with an Autocrib and a ton of tools, and they have been great at supplying it whenever we need more. It has helped a lot having an inventory system like that. It is reassuring to know that we have the best tools ready on hand so we can eliminate any potential downtime.

Master Machine is everywhere in the online machining community, specifically on Instagram. How has online marketing and social media changed the way you promote your business?

Geordan: Most people who run businesses seem to just hope that the word of mouth gets out there, or they have a website and hope it just goes viral one day and gets some attention. With the way the Internet is so crowded these days, you have to do something more to stand out. On our side, we have boosted our business through the use of paid online advertising with Google, boosting our SEO (Search Engine Optimization) to rank higher in search results, and being heavy users of social media like Instagram.

When I started the Master Machine Instagram account, I was really just using it to see what other machinists were doing. It was actually only a personal account for my use. I was skeptical of Instagram because of the Facebook community of machinists. I always viewed Facebook as a little more negative and less productive, while the Instagram community was much more collaborative.

mmm usa

I started by following people like Aeroknox, Kalpay, John Saunders, Bad Ass Machinists, and Tactical Keychains. I immediately noticed how helpful everyone was. I started posting as a business just about 2 years ago, when I posted our first version of the vise handles. Almost immediately people started asking to buy them. We were blown away by the response.

We didn’t set out to create something new with these handles, but by getting our name out there and filling a need for people following us, the hype continued to grow and grow and grow. Instagram has been a great tool for that aspect of the business, especially. We now have around 15 distributors across the US who are carrying our products, and are getting some great momentum. We also sell a lot of our products direct on our website, and 99% of that probably comes through Instagram.

Nace: We have actually landed distributors through someone following us online and going to their integrated distributor asking for our products. The distributor then called us and asked if they could carry our product on their shelves. Other online connections have also helped us land distributors through simple messages and phone calls.

Where do you see MMM USA in 10 years?

Nace: That’s a tough question…

At the shop, we always stress four major actions: Define, Act, Measure, and Refine. In our eyes, there are always better ways to do things and improve our processes. We hire people to have a growth mindset, and so we are redefining our future every day through our continual improvement process. We strive to always have that growth mindset to figure out how to do a job more efficiently. With constant improvement always taking place, it is hard to nail down exactly where the shop will be in 10 years, 5 years, or even 1 year from now. One thing is for sure – we will be successful.

Geordan: Something we do want to focus on is creating new assets, exploring new ventures, and doubling in size every year. We want to continue to release new products to build out our own product line and have MMM USA distributors worldwide.

Back in the day, Kurt Workholding was just a job shop, and now they are one of the most recognized workholding brands in the CNC machining industry. It is really hard to say where this ends or goes, but we think we have a bright future as both a job shop and as a supplier of our own OEM products for manufacturing.

vise handles

Are you currently hiring new machinists? If so, what qualities and skills do you look for?

Geordan: Every Tuesday we have an open interview at 4 PM. As you can imagine, with our company’s growth, we are constantly hiring. We are looking for people that are positive that have a growth mindset who can grow within the company. We always believe we can promote from within. Most of our people have been at Master Machine for 10-15 years because we can always move people up closer to the top and help them advance in their careers as we grow.

Nace: We are really focused on finding people with good attitudes, and people who want to be here. Skilled machinists are great, but they can be rare, so attitude and fitting in with the culture is huge. We can always take a good attitude and train the skill level up, but we can’t take a good skill level and change the bad attitude. We want team members who will coach each other up and help improve the team as a whole. We love working together and supporting the business together in every aspect of the business.

master machine

What is the best advice you have ever received?

Geordan: We really like “Notable Quotables.” Here are a couple of our favorites.

“The pen is for remembering, and the mind is for making decisions.”

We only have so much brain power to make crucial decisions, so we write all the day-to-day action items down on our checklists to make sure nothing is left undone. That frees our minds up from having to remember every little piece of the business so we can save that brain power for strategic decision making moments. We must be proactive and not reactive as we lead our team.

Nace: “Your employees want to follow someone who is always real, and not always right.”

As a leader, you need to take responsibility when you screw up, and be open with the team. Let them be a part of fixing the problem, and approach every situation looking at the positive.


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5 Questions to Ask Before Selecting an End Mill

Few steps in the machining process are as important as selecting the best tooling option for your job. Complicating the process is the fact that each individual tool has its own unique geometries, each pivotal to the eventual outcome of your part. We recommend asking yourself 5 key questions before beginning the tool selection process. In doing so, you can ensure that you are doing your due diligence in selecting the best tool for your application. Taking the extra time to ensure that you’re selecting the optimal tool will reduce cycle time, increase tool life, and produce a higher quality product.

Question 1: What Material am I Cutting?

Knowing the material you are working with and its properties will help narrow down your end mill selection considerably. Each material has a distinct set of mechanical properties that give it unique characteristics when machining. For instance, plastic materials require a different machining strategy – and different tooling geometries – than steels do. Choosing a tool with geometries tailored towards those unique characteristics will help to improve tool performance and longevity.

Harvey Tool stocks a wide variety of High Performance Miniature End Mills. Its offering includes tooling optimized for hardened steels, exotic alloys, medium alloy steels, free machining steels, aluminum alloys, highly abrasive materials, plastics, and composites. If the tool you’re selecting will only be used in a single material type, opting for a material specific end mill is likely your best bet. These material specific tools provide tailored geometries and coatings best suited to your specific material’s characteristics. But if you’re aiming for machining flexibility across a wide array of materials, Harvey Tool’s miniature end mill section is a great place to start.

Helical Solutions also provides a diverse product offering tailored to specific materials, including Aluminum Alloys & Non-Ferrous Materials; and Steels, High-Temp Alloys, & Titanium. Each section includes a wide variety of flute counts – from 2 flute end mills to Multi-Flute Finishers, and with many different profiles, coating options, and geometries.

Question 2: Which Operations Will I Be Performing?

An application can require one or many operations. Common machining operations include:

  • Traditional Roughing
  • Slotting
  • Finishing
  • Contouring
  • Plunging
  • High Efficiency Milling

By understanding the operations(s) needed for a job, a machinist will have a better understanding of the tooling that will be needed. For instance, if the job includes traditional roughing and slotting, selecting a Helical Solutions Chipbreaker Rougher to hog out a greater deal of material would be a better choice than a Finisher with many flutes.

Question 3: How Many Flutes Do I Need?

One of the most significant considerations when selecting an end mill is determining proper flute count. Both the material and application play an important role in this decision.

Material:

When working in Non-Ferrous Materials, the most common options are the 2 or 3-flute tools. Traditionally, the 2-flute option has been the desired choice because it allows for excellent chip clearance. However, the 3-flute option has proven success in finishing and High Efficiency Milling applications, because the higher flute count will have more contact points with the material.

Ferrous Materials can be machined using anywhere from 3 to 14-flutes, depending on the operation being performed.

Application:

Traditional Roughing: When roughing, a large amount of material must pass through the tool’s flute valleys en route to being evacuated. Because of this, a low number of flutes – and larger flute valleys – are recommend. Tools with 3, 4, or 5 flutes are commonly used for traditional roughing.

Slotting: A 4-flute option is the best choice, as the lower flute count results in larger flute valleys and more efficient chip evacuation.

Finishing: When finishing in a ferrous material, a high flute count is recommended for best results. Finishing End Mills include anywhere from 5-to-14 flutes. The proper tool depends on how much material remains to be removed from a part.

High Efficiency Milling: HEM is a style of roughing that can be very effective and result in significant time savings for machine shops. When machining an HEM toolpath, opt for 5 to 7-flutes.

end mill selection

Question 4: What Specific Tool Dimensions are Needed?

After specifying the material you are working in, the operation(s) that are going to be performed, and the number of flutes required, the next step is making sure that your end mill selection has the correct dimensions for the job. Examples of key considerations include cutter diameter, length of cut, reach, and profile.

Cutter Diameter

The cutter diameter is the dimension that will define the width of a slot, formed by the cutting edges of the tool as it rotates. Selecting a cutter diameter that is the wrong size – either too large or small – can lead to the job not being completed successfully or a final part not being to specifications.  For example, smaller cutter diameters offer more clearance within tight pockets, while larger tools provide increased rigidity in high volume jobs.

Length of Cut & Reach

The length of cut needed for any end mill should be dictated by the longest contact length during an operation. This should be only as long as needed, and no longer. Selecting the shortest tool possible will result in minimized overhang, a more rigid setup, and reduced chatter. As a rule of thumb, if an application calls for cutting at a depth greater than 5x the tool diameter, it may be optimal to explore necked reach options as a substitute to a long length of cut.

Tool Profile

The most common profile styles for end mills are square, corner radius, and ball. The square profile on an end mill has flutes with sharp corners that are squared off at 90°. A corner radius profile replaces the fragile sharp corner with a radius, adding strength and helping to prevent chipping while prolonging tool life. Finally, a ball profile features flutes with no flat bottom, and is rounded off at the end creating a “ball nose” at the tip of the tool. This is the strongest end mill style.  A fully rounded cutting edge has no corner, removing the mostly likely failure point from the tool, contrary to a sharp edge on a square profile end mill. An end mill profile is often chosen by part requirements, such as square corners within a pocket, requiring a square end mill.  When possible, opt for a tool with the largest corner radius allowable by your part requirements. We recommend a corner radii whenever your application allows for it. If square corners are absolutely required, consider roughing with a corner radius tool and finishing with the square profile tool.

Question 5: Should I use a Coated Tool?

When used in the correct application, a coated tool will help to boost performance by providing the following benefits:

  • More Aggressive Running Parameters
  • Prolonged Tool life
  • Improved Chip Evacuation

Harvey Tool and Helical Solutions offer many different coatings, each with their own set of benefits. Coatings for ferrous materials, such as AlTiN Nano or TPlus, typically have a high max working temperature, making them suitable for materials with a low thermal conductivity. Coatings for non-ferrous applications, such as TiB2 or ZPlus, have a low coefficient of friction, allowing for easier machining operations. Other coatings, such as Amorphous Diamond or CVD Diamond Coatings, are best used in abrasive materials because of their high hardness rating.

Ready to Decide on an End Mill

There are many factors that should be considered while looking for the optimal tooling for the job, but asking the aforementioned five key question during the process will help you to make the right decision. As always, The Harvey Performance Company Technical Service Department is always available to provide recommendations and walk you through the tool selection process, if need be.

Harvey Tool Technical Support: 800-645-5609

Helical Solutions Technical Support: 866-543-5422

University of Michigan Formula SAE Racing Team – Featured Customer

Formula SAE is a student design competition that began in 1980. The competition was founded by the SAE (Society of Automotive Engineers) branch at the University of Texas. Each year, hundreds of universities across the world spend months designing and manufacturing their best Formula style car before putting them to the test in competitions.

Alex Marshalek is the Team Captain of the University of Michigan’s Formula SAE team, MRacing. The team was originally founded in 1986, and has been very successful over the years. In the 2017 season, they finished 5th at the Formula SAE Michigan event, and took home a 1st place finish at Formula North. They are hoping to continue riding that momentum into another successful season in 2018.

Mracing

Alex reached out to Harvey Tool and Helical earlier this year, and after some conversation, the decision was made to sponsor their team’s efforts by supplying cutting tools and providing technical support. With competitions on the horizon and a new build coming over the summer, Alex was kind enough to find some time to talk with us about his experiences as a student learning the ropes in engineering, manufacturing, and design, the importance of quality tooling and maintaining a superior part finish for competition, and challenges he has faced during this process.

Hi Alex. Thanks for taking the time to talk with us today. When you were looking into college degree programs, what initially interested you in manufacturing and engineering?

I have always had an interest in Aerospace Engineering, but it was nothing more than a personal interest until I started college. My high school unfortunately did not have any machine shop or manufacturing type classes, so a lot of what I knew, I learned from my dad. My dad worked as a Mechanical Engineer at an axle manufacturing company, and he used to always be doing things around the house and showing me the basics of engineering and design.

When it came time to choose a school, I knew that Michigan had an impressive Aerospace Engineering department, and I liked the feel of the campus and community better than other schools I had toured.

How did you first get involved with the Formula SAE team?

I knew going into school that I wanted to get involved in a design team and advance my learning in that way. We have about a dozen different design teams at Michigan, but the Formula SAE team really stood out to me as a really cool project to get involved in.

I started with the team in Fall of 2016, helping out with the design and manufacturing of the vehicle’s suspension. Now, for the upcoming 2018 season, I am taking over the role of Team Captain. There will be a little bit less hands-on design and manufacturing work for me as it is more of an administrative/outreach role.

michigan racing

How does a typical FSAE season run?

So FSAE seasons are constantly running, and nearly overlapping with each other. For example, we are currently finishing up competitions from the 2018 season, but at the same time we are beginning the design of the vehicle for the 2019 season. Typically, the design work is done over the summer, and finalized in October. After that, the major manufacturing begins and lasts until about March, with spare parts and additions being added as we go. Testing begins in March, where we fine tune the vehicle and optimize the design for performance. Then, the rest of the Spring and early Summer is competition time, and the process starts all over again!

What sort of machines do you have in the shop?

Right now, we have three manual Bridgeport mills, two retro-fit CNC Bridgeport mills, 2 manual lathes, 1 retro-fit CNC lathe, and a Haas VF-2SS and Haas SL-20. For the vast majority of what we are machining, we are using the Haas. We do most of our work in Aluminum, with some parts made out of steel or titanium, and the Haas has been great for everything.

We are also using AutoDesk’s Fusion 360 software for our CAD/CAM, and we love it.

What has been the most difficult part of the build?

Time is really the biggest challenge. We are all full-time students, so time is already hard to find, but we also don’t have an overabundance of machinists so the operators can get overburdened. It all works out in the end and our machinists are great, but time management is truly the biggest challenge.

michigan formula sae

The composite materials we work with are also very challenging to machine. We constructed the vehicle’s monocoque (the structural “skin”, often seen in Formula One cars) out of carbon fiber. While we cut a lot of it on the water jet machine, we needed more precise holes than a water jet could offer, so we went to the Haas for that. We were using HSS drills and only getting 10-12 holes at a time before they wore out. However, we had Don Grandt (Harvey Performance Company Application Engineer) stop in the shop and he sent us a few Harvey Tool diamond coated drills, which should make this a much faster and more precise process!

You mentioned Don stopped in to give you guys a visit. What were some of your biggest takeaways?

Don was great. He stopped by and we gave him a tour of the facility and showed off some of the parts we were designing. We talked shop for quite a bit, and he gave us a bunch of great tips and tricks we could use to really optimize our machining. As I mentioned, he also went through the catalogs with us and helped us find exactly what we need for tooling. The Harvey Tool diamond coated drills are going to be a life saver for carbon fiber. I guess the biggest takeaway was just all of the knowledge we received from Don and how helpful that was to have someone direct from the tooling manufacturer sharing everything we knew with us.

Now that you have the Harvey and Helical tools in the shop, how have they helped you complete this project and get a leg up on your competition?

One of the most impressive things for us have been the finishing end mills we received. The Helical finishers for Aluminum are giving us some of the best finishes we have ever seen. For us, that is a point of pride. We not only want to have the fastest and most well-designed vehicle, but we also want to have the best looking parts. Subpar finishes reflect poorly on the entire build, and first impressions mean a lot in these competitions.

We have also been blown away by the Chipbreaker roughers. We absolutely love those tools and push them to the limits with great results. In fact, the first time we ran them, we used Machining Advisor Pro to dial in our speeds and feeds, and the numbers seemed insane to us. We were nervous, but we pushed the button and let it run. It was amazing to see that we could push a tool that fast without tool failure.

How has your experience been using Machining Advisor Pro?

We use Machining Advisor Pro every time we picked up the Helical end mills. MAP was actually one of the main reasons we were looking for Helical to sponsor us. We had heard a lot about MAP and your level of technical support, which was important to us as we are learning more about manufacturing and machining. Machining Advisor Pro has quickly become one of our best learning tools in the shop.

The nice thing about MAP is that is takes a look at all of the parameters. A lot of applications only give you numbers on your speeds and feeds, but MAP takes a look at the depth of cut, chip thinning, engagement angle, and all of the other parameters that are so essential to a successful run. As a result, we have been able to get very aggressive with the end mills. We are not a huge production shop, so cycle times are not as important, but we still want to get the most out of our tools in the least amount of possible time.

So, let’s break down some specs. What are you all working with on this year’s build?

Right now our car features a 4 cylinder Honda 600 CBR engine, with a Turbo and 600cc displacement. We are one of the few teams that run a turbo in competition. As we mentioned, the monocoque is completely carbon fiber, and the car features a full aero package with an undertray. The max speed is around 80 MPH, and the car weighs 420 pounds without the driver.

Once the build is complete, how does a typical competition work?

Most of the Formula SAE competitions are multi-day events, with a few static events, and then dynamic events where the car is running. For static events, we first have a Design portion. We validate and argue for our design in front of judges who are engineers in the industry. Then, we get into a Cost presentation, as one of the goals is to build the cheapest possible car with a high level of performance. That balance of cost vs. performance is a critical part of the build. The last static event is a Business presentation, where we introduce a business/manufacturing plan on how to get this design to a production level of 100 units in a year.

For the dynamic events, we have 4 different tests. First, we have the Accel Run, which is a 75 meter sprint, and the fastest cars win. From there we go to the Skip Pad event, which is centered on turning radius and the stiffness of the chassis as we do tight figure eight turns with the car.

University of Michigan FSAE

Then we have the AutoCross, a one lap race, which determines our placement in the final event; Endurance. For the Endurance event, we drive the cars around a 22km track, and the goal is to finish the race without any mechanical or design failures in the quickest time possible. Only around 50% of participants actually complete this event. If a single part falls off, or breaks, you are disqualified. Many times we see things like the suspension, powertrain, or wings falling off. It is disappointing when it happens, but it allows us to easily identify any flaws and fix them for the next event.

What is next for you after school? Any future plans or goals?

I am currently majoring in Aerospace Engineering, and would like to stay within that industry. I am leaning towards working on aircraft. Designing either aircraft structures or the aerodynamics would be very cool. I really like the size and scale of working on commercial aircraft, but I could see myself doing something more specialty like working in Defense as well.


Alex and his team had a very successful 2018 season. They recently placed 9th overall in a competition at the Michigan International Speedway. In the dynamic events, they placed 4th in Skidpad, and 7th in Autocross. The high placement in the Autocross event allowed them to race head to head against top teams in the world, and they ended up placing 4th in Endurance out of 104 cars!

The MRacing team also competed at Formula North, a competition in Ontario, Canada, where they achieved a top ranking of 2nd place overall. They passed all of the technical inspections on the first try and placed 1st in Acceleration, 2nd in Skidpad and Endurance, 3rd in Autocross, and 4th in Efficiency.

michigan fsae

Slaying Stainless Steel: Machining Guide

Stainless steel can be as common as Aluminum in many shops, especially when manufacturing parts for the aerospace and automotive industries. It is a fairly versatile material with many different alloys and grades which can accommodate a wide variety of applications. However, it is also one of the most difficult to machine. Stainless steels are notorious end mill assassins, so dialing in your speeds and feeds and selecting the proper tool is essential for machining success.

Material Properties

Stainless steels are high-alloy steels with superior corrosion resistance to carbon and low-alloy steels. This is largely due to their high chromium content, with most grades of stainless steel alloys containing at least 10% of the element.

Stainless steel can be broken out into one of five categories: Austenitic, Ferritic, Martensitic, Precipitation Hardened (PH), and Duplex. In each category, there is one basic, general purpose alloy. From there, small changes in composition are made to the base in order to create specific properties for various applications.

For reference, here are the properties of each of these groupings, as well as a few examples of the popular grades and their common uses.

Category Properties Popular Grades Common Uses
Austenitic Non-magnetic, outstanding corrosion and heat resistance. 304, 316 Food processing equipment, gutters, bolts, nuts, and other fasteners.
Ferritic Magnetic, lower corrosion and heat resistance than Austenitic. 430, 446 Automotive parts and kitchen appliances.
Martensitic Magnetic, moderate corrosion resistance – not for severe corrosion. 416, 420, 440 Knives, firearms, surgical instruments, and hand tools.
Precipitation Hardened (PH) Strongest grade, heat treatable, severe corrosion resistance. 17-4 PH, 15-5 PH Aerospace components.
Duplex Stronger mixture of both Austenitic and Ferritic. 244, 2304, 2507 Water treatment plants, pressure vessels.

Tool Selection

Choosing the correct tooling for your application is crucial when machining stainless steel. Roughing, finishing, slotting, and high efficiency milling toolpaths can all be optimized for stainless steel by choosing the correct style of end mill.

Traditional Roughing

For traditional roughing, a 4 or 5 flute end mill is recommended. 5 flute end mills will allow for higher feed rates than their 4 flute counterparts, but either style would work well for roughing applications. Below is an excellent example of traditional roughing in 17-4 Stainless Steel.

 

 

Slotting

For slotting in stainless steel, chip evacuation is going to be key. For this reason, 4 flute tools are the best choice because the lower flute count allows for more efficient chip evacuation. Tools with chipbreaker geometry also make for effective slotting in stainless steel, as the smaller chips are easier to evacuate from the cut.

stainless steel machining

Finishing

When finishing stainless steel parts, a high flute count and/or high helix is required for the best results. Finishing end mills for stainless steel will have a helix angle over 40 degrees, and a flute count of 5 or more. For more aggressive finishing toolpaths, flute count can range from 7 flutes to as high as 14. Below is a great example of a finishing run in 17-4 Stainless Steel.

 

High Efficiency Milling

High Efficiency Milling can be a very effective machining technique in stainless steels if the correct tools are selected. Chipbreaker roughers would make an excellent choice, in either 5 or 7 flute styles, while standard 5-7 flute, variable pitch end mills can also perform well in HEM toolpaths.

stainless steel

HEV-5

Helical Solutions offers the HEV-5 end mill, which is an extremely versatile tool for a variety of applications. The HEV-5 excels in finishing and HEM toolpaths, and also performs well above average in slotting and traditional roughing. Available in square, corner radius, and long reach styles, this well-rounded tool is an excellent choice to kickstart your tool crib and optimize it for stainless steel machining.

stainless steel machining

Running Parameters

While tool selection is a critical step to more effective machining, dialing in the proper running parameters is equally important. There are many factors that go into determining the running parameters for stainless steel machining, but there are some general guidelines to follow as a starting point.

Generally speaking, when machining stainless steels a SFM of between 100-350 is recommended, with a chip load ranging between .0005” for a 1/8” end mill up to .006” for a 1” end mill. A full breakdown of these general guidelines is available here.

Machining Advisor Pro

Machining Advisor Pro is a cutting edge resource designed to precisely calculate running parameters for high performance Helical Solutions end mills in materials like stainless steel, aluminum, and much more. Simply input your tool, your exact material grade, and machine setup and Machining Advisor Pro will generate fully customizable running parameters. This free resource allows you to push your tools harder, faster, and smarter to truly dominate the competition.

In Conclusion

Stainless steel machining doesn’t have to be hard. By identifying the proper material grade for each part, selecting the perfect cutting tool, and optimizing running parameters, stainless steel machining headaches can be a thing of the past.

Tips for Machining Gummy Materials

Machinists face many problems and challenges when manufacturing gummy materials. These types of materials include low carbon steels, stainless steels, nickel alloys, titanium, copper, and metals with high chromium content. Gummy materials have a tendency to produce long, stringy chips, and are prone to creating built-up edge. These common problems can impact surface finish, tool life, and part tolerances.

Continuous Chip With a Built-Up Edge

Continuous chips are long, ribbon-like chips that are formed when the tool cuts through a material, separating chips along the shear plane created by the tool’s cutting edge. These chips slide up the tool face at a constant flow to create a long and stringy chip. The high temperatures, pressures, and friction produced when cutting are all factors that lead to the sticky chips that adhere to the cutting edge. When this built up edge becomes large enough, it can break off leaving behind some excess material on the workpiece, or gouge the workpiece leaving a poor surface finish.

Coolant

Using large amounts of coolant can help with temperature control and chip evacuation while machining gummy materials. Temperature is a big driving force behind built-up edge. The higher the temperature gets, the easier and faster a built-up edge can form. Coolant will keep local temperatures lower and can prevent the material from work hardening and galling. Long, stringy chips have the potential to “nest” around the tool and cause tool failure. Coolant will help break these chips into smaller pieces and move them away from the cutting action by flash cooling them, resulting in fracturing of the chip into smaller pieces. Coolant should be applied directly to the contact area of the tool and workpiece to have the maximum effect.

Tool Engagement

Running Parameters

The tool should be constantly fed into the workpiece. Allowing the tool to dwell can cause work hardening and increase the chance of galling and built up edge. A combination of higher feed rates and lower speeds should also be used to keep material removal rates at a reasonable level. An increase in feed rates will raise the temperature less than an increase in speed. This relates to chip thinning and the ability of a tool to cut the material rather than rub against it.

Climb Milling

Climb milling is the preferred method as it directs more heat into the chip than the tool. Using climb milling, the largest chip cross section is created first, allowing the tool to cut through the material much easier. The heat generated from friction when the tool penetrates the workpiece is transferred to the chip rather than the tool because the thickest part of the chip is able to hold more heat than the thinnest.

climb milling

Initial Workpiece Engagement

Sudden, large changes in force, like when a tool initially engages a workpiece, have a negative impact on tool life. Using an arc-in tool path to initially engage the material allows for increased stability with a gradual increase in cutting forces and heat. A gradual tool entry such as this is always the preferred method over an abrupt straight entry.

Tool Selection

A tool with a sharp and robust cutting edge should be selected to machine gummy materials. Helical has tooling specifically designed for Titanium and Stainless Steel to make your tool selection process easy.

Additionally, choosing a tool with the correct coating for the material you are machining will help to protect the cutting edge and result in a far lower chance of built up edge or galling than an uncoated tool. A tool with a higher flute count can spread tool wear out over multiple cutting edges, extending tool life. Tool wear is not always linear in gummy materials; as soon as a little bit of wear appears, tool failure will happen relatively quickly. Changing the tool at the first sign of wear may be necessary to ensure that parts are not scrapped.

Gummy Materials Summarized

Every material machines somewhat differently, but understanding what is happening when the tool cuts the workpiece and how this affects tool life and finish will go a long way to successfully completing any job.  Built-up edge and excess heat can be minimized by selecting the correct tool and coating for the material, and following the tips and techniques mentioned above. Finally, be sure to check your machine’s runout and ensure maximum rigidity prior to beginning your machining operation.

Attacking Aluminum: A Machining Guide

Aluminum is one of the most commonly machined materials, as most forms of the material feature excellent machinability, and is thus a commonly used material in manufacturing. Because of this, the competition for aluminum machining can be intense. Understanding the basics behind tool selection, running parameters, and advanced milling techniques for aluminum can help machinists earn a competitive advantage.

Material Properties

Aluminum is a highly formable, workable, lightweight material. Parts made from this material can be found in nearly every industry. Additionally, Aluminum has become a popular choice for prototypes due to its low-cost and flexibility.

Aluminum is available in two basic forms: Cast and Wrought. Wrought Aluminum is typically stronger, more expensive, and contains a lower percentage of outside elements in its alloys. Wrought Aluminum is also more heat-resistant than Cast and has a higher level of machinability.

Cast Aluminum has less tensile strength but with a higher flexibility. It costs less, and has higher percentages of outside elements (silicon, magnesium, etc.) in its alloys, making it more abrasive than Wrought.

Tool Geometry

There are a few coating options available for Aluminum tooling, including the popular gold-colored ZrN (Zirconium Nitride) and the lesser known but highly effective TiB2 (Titanium Diboride). Uncoated tooling can also provide solid machining performance. However, the real key to high performance machining in Aluminum is knowing the proper flute count and helix angle required for your operation.

Flute Count

End mills for aluminum are often available in either 2 flute or 3 flute styles. With higher flute counts, it would become difficult to evacuate chips effectively at the high speeds at which you can run in aluminum. This is because aluminum alloys leave a large chip, and chip valleys become smaller with each additional flute on an end mill.

flute count for aluminum

Traditionally, 2 flute end mills have been the preferred choice for Aluminum. However, 3 flute end mills have proven to be more successful in many finishing operations, and with the right parameters they can also work successfully as roughers. While much of the debate between 2 and 3 flute end mills for Aluminum boils down to personal preference, the operation, rigidity, and desired material removal rates can also have an effect on tool selection.

Helix Angles

The helix angle of a tool is measured by the angle formed between the centerline of the tool and a straight line tangent along the cutting edge. Cutting tools for aluminum typically feature higher helix angles than standard end mills. Specialized helix angles for Aluminum are typically either 35°, 40°, or 45°. Variable helix tools are also available and make a great choice for reducing chatter and harmonics while also increasing material removal rates.

Aluminum Machining

A helix angle of 35° or 40° is a good choice for traditional roughing and slotting applications. A 45° helix angle is the preferred choice for finishing, but also for High Efficiency Milling toolpaths as the high helix angle wraps around the tool faster and makes for a more aggressive cut.

Tooling Options

When machining aluminum, standard 2 or 3 flute tools will often get the job done. However, for certain applications and machine setups there are some more tooling options to consider for even better performance.

Chipbreaker Tooling

One of the most important things to consider when machining aluminum (and many other materials) is effective chip evacuation. Standard 2-3 flute end mills running at recommended speeds and feeds and proper chip loads can evacuate chips fairly well. However, 3 flute chipbreaker tooling can run at increased speed and feed rates for even better performance. The unique offset chip breaker geometry creates smaller chips for optimal evacuation while still leaving a semi-finished surface.

Chipbreaker Aluminum

These tools are excellent for more advanced toolpaths like High Efficiency Milling, which is another important tool for a successful aluminum machining experience.

High Balance End Mills

High balance end mills are designed to significantly increase performance in highly balanced machining centers capable of elevated RPMs and feed rates. These tools are precision balanced specifically for high velocity machining in aluminum (up to 33,000 RPM).

High Balance Tools for Aluminum

Helical Solutions offers high balance tooling in standard 2 flute styles, as well as coolant-through 3 flute styles for reduced heat, enhanced chip evacuation, and increased material removal rates. These tools, like the chipbreakers, are also an excellent choice for High Efficiency Milling toolpaths.

Running Parameters

Setting the right parameters for aluminum applications is vital to optimizing productivity and achieving better machining results. Since aluminum is an easier material to machine, pushing your machine to its limits and getting the most out of your tool is vital to stay ahead of the competition and keep winning business.

While there are many factors that go into the parameters for every job, there are some general guidelines to follow when machining aluminum. For cast aluminum alloys (i.e. 308, 356, 380), a surface footage of 500-1000 SFM is recommended, with RPMs varying based on cutter diameter. The basic calculation to find a starting point for RPMs would be (3.82 x SFM) / Diameter.

In wrought aluminum alloys (i.e. 2024, 6061, 7075), a surface footage of 800-1500 SFM is recommended, with the same calculation being used to find a starting point for RPMs.

High Efficiency Milling

High Efficiency Milling, commonly known as HEM, is a strategy that is rapidly gaining popularity in the manufacturing industry. Many CAM programs are now including HEM toolpaths, and while virtually any machine can perform HEM, the CNC controller must feature a fast processor to keep up with the additional lines of code. A great example of High Efficiency Milling toolpaths in Aluminum can be seen below.

At its core, HEM is a roughing technique that utilizes a low Radial Depth of Cut (RDOC) and a high Axial Depth of Cut (ADOC) to take full advantage of the cutting edge of the tool. To learn more about how High Efficiency Milling can increase your efficiency, extend your tool life to keep costs down, and get greater performance for aluminum (and other materials), click here to download the HEM Guidebook.

In Summary

Aluminum is a versatile material with a high level of machinability, but it should not be overlooked. Understanding the best ways to tackle it is important for achieving the desired results. Optimizing your tool crib, machine setups, and toolpaths for aluminum is essential to stay ahead of the competition and make your shop more efficient.

What You Need to Know About Coolant for CNC Machining

Coolant in purpose is widely understood – it’s used to temper high temperatures common during machining, and aid in chip evacuation. However, there are several types and styles, each with its own benefits and drawbacks. Knowing which coolant – or if any – is appropriate for your job can help to boost your shop’s profitability, capability, and overall machining performance.

Coolant or Lubricant Purpose

Coolant and lubricant are terms used interchangeably, though not all coolants are lubricants. Compressed air, for example, has no lubricating purpose but works only as a cooling option. Direct coolants – those which make physical contact with a part – can be compressed air, water, oil, synthetics, or semi-synthetics. When directed to the cutting action of a tool, these can help to fend off high temperatures that could lead to melting, warping, discoloration, or tool failure. Additionally, coolant can help evacuate chips from a part, preventing chip recutting and aiding in part finish.

Coolant can be expensive, however, and wasteful if not necessary. Understanding the amount of coolant needed for your job can help your shop’s efficiency.

Types of Coolant Delivery

Coolant is delivered in several different forms – both in properties and pressure. The most common forms include air, mist, flood coolant, high pressure, and Minimum Quantity Lubricant (MQL). Choosing the wrong pressure can lead to part or tool damage, whereas choosing the wrong amount can lead to exhausted shop resources.

Air: Cools and clears chips, but has no lubricity purpose. Air coolant does not cool as efficiently as water or oil-based coolants. For more sensitive materials, air coolant is often preferred over types that come in direct contact with the part. This is true with many plastics, where thermal shock – or rapid expansion and contraction of a part – can occur if direct coolant is applied.

Mist: This type of low pressure coolant is sufficient for instances where chip evacuation and heat are not major concerns. Because the pressure applied is not great in a mist, the part and tool do not undergo additional stresses.

Flood (See Video Below): This low pressure method creates lubricity and flushes chips from a part to avoid chip recutting, a common and tool damaging occurrence.

High Pressure (See Video Below): Similar to flood coolant, but delivered in greater than 1,000 psi. This is a great option for chip removal and evacuation, as it blasts the chips away from the part. While this method will effectively cool a part immediately, the pressure can be high enough to break miniature diameter tooling. This method is used often in deep pocket or drilling operations, and can be delivered via coolant through tooling, or coolant grooves built into the tool itself. Harvey Tool offers Coolant Through Drills and Coolant Through Threadmills.

Minimum Quantity Lubricant (MQL): Every machine shop focuses on how to gain a competitive advantage – to spend less, make more, and boost shop efficiency. That’s why many shops are opting for MQL, along with its obvious environmental benefits. Using only the necessary amount of coolant will dramatically reduce costs and wasted material. This type of lubricant is applied as an aerosol, or an extremely fine mist, to provide just enough coolant to perform a given operation effectively.

In Conclusion

Coolant is all-too-often overlooked as a major component of a machining operation. The type of coolant or lubricant, and the pressure at which it’s applied, is vital to both machining success and optimum shop efficiency. Coolant can be applied as compressed air, mist, in a flooding property, or as high pressure. Certain machines also are MQL able, meaning they can effectively restrict the amount of coolant being applied to the very amount necessary to avoid being wasteful.