Multi-Axis Finisher Q&A

What is a Multi-Axis Finisher?

A tool that uses an extremely large radius to increase finishing performance in two different ways, depending on the needs of the machinist. Either the Multi-Axis Finisher will provide a better surface finish than a traditional Ball End Mill in the same amount of time, or will provide the same surface finish in far less time than a traditional Ball End Mill. A middle ground with improved surface finish and reduced cycle time is also easily achievable.

What Are Other Names for Multi-Axis Finishers?

Multi-Axis Finishers are oftentimes referred to as Barrel Cutters or Conical Barrel Mills or Circle Segment Cutters, among many others.

What Are the Different Forms of Multi-Axis Finishers, and How Do They Differ?

There are several different forms of Multi-Axis Finishers, including Lens, Taper, Oval, and Barrel. With a Lens Form, there’s a large radius on the end of the tool that’s in line with the tool axis. Taper Form, in contrast, has three tangential radii and a large radius defined at a specific angle relative to the tool axis. An Oval Form has two tangential radii, offering additional angle flexibility, while a Barrel Form has a large radius on the OD of the tool.

The most significant benefit is oftentimes observed utilizing a Taper Form Multi-Axis Finisher, as the radius of this tool can become vastly large on this form, while the others are more limited. However, this great benefit also comes with the least amount of flexibility in terms of approach to a workpiece.

What Are the Benefits of a Multi-Axis Finisher?

There are two clear benefits to using a Multi-Axis Finisher, compared to a Ball End Mill: Increased surface finish, and reduced cycle time (Or most likely both, concurrently).

What is a Benefit Multiple?

Helical Solutions is the industry’s premier manufacturer of Multi-Axis Finishers, and the Benefit Multiple is a significant reason why. Helical specifies the theoretical benefit that can be seen with its Multi-Axis Finishers, providing machinists direct insight into the gains that can be realized with these tools.

Benefit Multiple refers to the Cusp Height, correlated directly with the theoretically-achievable surface finish. Assuming the same cusp height from a Ball End Mill to a Multi-Axis Finisher, the Benefit Multiple relates to the time savings that could be seen in a machinists’ toolpath. For example, a Benefit Multiple of 4 would result in a toolpath ¼ as long as for a Ball End Mill of the same diameter. The stepover pass-to-pass would be 400% as much as a Ball End Mill to keep the same cusp.

When Should I Not Use a Multi-Axis Finisher?

Multi-Axis Finishers are best applied to wide-open surface areas; or large, smooth contours rather than small features or tight areas. Application of these tools will always be on a case-by-case basis. For help with your specific application, contact Helical Solutions Technical Support at 866-543-5422.

How Can I Get the Most Out of My Multi-Axis Finisher?

Multi-Axis finishers are best utilized when working further towards the OD of the tool. Tapered Form Multi-Axis Finishers are the most obvious choice for this, as its nose radius is small and has the least amount of efficiency. Similarly to a ball end mill, working near the center will have limited cutting ability, while the OD of the tool will see the full surface footage of the programmed RPM.

Taper Form Multi-Axis Finishers should be used when tilted at the specified taper angle. Oval Form Multi-Axis Finishers should be used towards the OD. Lens Form Multi-Axis Finishers should be tilted to avoid working on-center.

Lens Form Multi-Axis Finishers Look Like a High Feed End Mill. Can I Use it That Way?


Yes. However, there are differences in the form, and while a Lens Form Multi-Axis Finisher could theoretically be used as a High Feed End Mill, the two tools are not interchangeable.  A High Feed End Mill would not be the best choice for Multi-Axis Finishing, nor would a Lens Form Multi-Axis Finisher be our first recommendation for feed milling.

Do I need special software to program Multi-Axis Finishers?

Yes. A number of years ago, there were only a few CAM software packages that supported the programming of these specific forms. Nowadays, most CAM software providers have some degree of support for this method. Two of the first CAM software offerings to support this were MasterCAM and Hypermill, though many additional options exist today.

Why haven’t I heard of Multi-Axis Finishers Until Now?

In the grand scheme of things, Multi-Axis Finishers provide a very new approach to finishing, having been developed within the last handful of years.  Similar to High Efficiency Milling, these tools offer a new technique to approach your workpiece, offering increased efficiency and reduced cycle times.  Compared to the history of milling, modern tool manufacturing and CAM software have only just become able to program these unique forms.  Multi-axis finishers are positioned to revolutionize the world of finishing.

For more information on Multi-Axis Finishers, visit Multi-Axis Finishers: The Key to Amazing Surface Finish.

Multi-Axis Finishers: The Key to Amazing Surface Finish

A Key to Improving Surface Finish

In today’s Manufacturing Industry, part finish and machining efficiency are key to a successful machine shop. It’s no surprise, therefore, that the popularity Multi-Axis Finishers has never been greater. Helical Solutions is a leader in the manufacturing of Multi-Axis Finishers, and its customers utilize this impressive tool when faced with extremely high surface finish requirements, oftentimes swapping out a traditional Ball End Mill to dramatically improve finish while minimizing cycle times.

Multi-Axis Finisher Basic Principles

A Multi-Axis Finisher can be easily recognized by its large radius included in the profile of the tool. With a larger radius, a far greater stepover can be used pass-to-pass while keeping the same cusp height as a Ball End Mill. This decreases the cycle time by a known value called the Benefit Multiple.

A Multi-Axis Finisher with a Benefit Multiple of 8 will reduce the cycle time to 1/8 of the cycle time for a Ball End Mill of the same shank diameter – an 87.5% time savings! If a Multi-Axis Finisher is used with the same pass-to-pass stepover as a Ball End Mill, the finish will be drastically improved due to exponentially smaller cusp heights. Most situations allow both reduced cycle time and improved surface finish to be achieved.

The images below show the comparison of a ball end mill to an Oval Shape Multi-Axis Finisher with a benefit multiple of 4.

Due to their large radii, Multi-Axis Finishers are best suited for wide open, flowing, and somewhat flat surfaces. Smaller spaces, especially tight corners, will generally not see as much benefit from these tools due to limited use of the major radius.

Multi-Axis Finisher Tool Selection

The Manufacturing Industry’s leader in Multi-Axis Finishers, Helical Solutions offers 3 distinct profiles, each fully stocked and available to ship the day of purchase.

Oval Form Multi-Axis Finishers

The oval form includes 2 tangential radii and offers the most versatility in smaller spaces where a slightly varied approach angle is required, such as impellers or fan blades.

Taper Form Multi-Axis Finishers

The taper form includes 3 tangential radii and a taper angle. It allows for the largest radius, and therefore greatest potential improvement of finish and reduction of cycle time. They are best used where a specific approach angle is needed and where maximum performance gain is desired.

Lens Form Multi-Axis Finishers

The lens form includes 2 tangential radii on the end of the tool and is used for work mostly on the face of a part. Tilt angles of approximately 5 degrees are recommended for these tools to avoid working on-center.

Programming Multi-Axis Finishers

Programming Multi-Axis Finishers requires some additional consideration compared to a typical end mill. Luckily, many modern CAM packages offer support for these unique profiles, including many of Helical’s CAM partners. Each software has their own name for these toolpaths, so reach out to your CAM or Helical sales rep to find how you can program yours!

For more information on Multi-Axis Finishers, and to learn if this advantageous tool is right for you, read our Multi-Axis Finishers Q&A.

Carbon Fiber Reinforced Polymers (CFRP): Material Properties & Tool Selection

Carbon Fiber Reinforced Polymers (CFRP) is composed of carbon fibers, bound with resin, to create a groundbreaking material that has proven to have limitless application possibilities in a wide range of composite cutting industries. Due to its attractive properties of strength, durability, corrosion resistance, and its lightweight nature, there has been a rising utilization of carbon fiber in the aerospace and automotive industries. However, it does not come without its own set of challenges in comparison to typical metal machining.

Three sheets of cfrp carbon fiber material on top of one another

CFRP Properties

CFRP has a high resistance to being deformed without permanent effects (elastic modulus), resistance to tension, low thermal conductivity, and low thermal expansion. While many of these properties are ideal for many applications, there are unique effects that must be considered when machining.

Abrasiveness

CFRP’s high elastic modulus makes it highly abrasive, causing challenges in tool wear and tool life that must be addressed. For example, while milling typical metals, clean chips are formed and ejected. But milling carbon fiber is like sanding, where material is removed in the form of dust particles.

Abrasion is a large issue in carbon fiber machining as it is responsible for poor tool life and dullness of the tool that can cause a part to be scrapped. As soon as a tool begins to dull, it will cause poor part finish and increase the chances of delamination and fraying.

Causes of Heat Generation

Typically, in metal machining, most of the heat is transferred into the chips with a fraction of the heat into the part and workpiece. Due to CFRP’s low thermal conductivity and no chips formed to dissipate the heat, most of the heat is transferred to the tool and part. This heat is unideal, as it will cause more tool wear and potentially cause damage, resulting in delamination.

For more information on composite delamination, read “Overcoming Composite Holemaking Challenges.”

Varying Properties

No composition of CFRP is made the same, meaning that operating parameters can vary. There is no one-solution-fits-all for every application, as it is often found to be less predictable than metals due to its varying properties. These varying components includes the fiber type, fiber density, resin type, layup orientations, thickness, matrix hardness, and heat sensitivity, which all must be taken into consideration.

Methods to Reduce CFRP Issues

Having high interval checks to monitor cutting and dimension quality to catch any errors before they may be irreversible is one way address CFRP machining issues. Another method to tackle CFRP would be through picking the right tool for the application.

Selecting a CFRP Tool

Tooling material type (substrate) and geometry both determine the quality of cutting the carbon fiber and durability of the tool.

Tooling Substrate/Coating

When selecting a tool to machine CFRP materials, it is essential to opt for a tool that is strong, sharp, and resistant to the abrasive properties that CFRP holds. Many machinists opt for solid carbide cutters with diamond coatings such as DLC, CVD, or PCD, as they provide the tooling with increased tool life and improved cutting action. These tools provide added hardness and abrasion resistance to combat the effects of machining CFRP.

Corehog end mill coating chart for selecting a tool to machine cfrp carbon fiber materials
CoreHog’s Coating Chart

While PCD diamond tools are considerably higher in price than other diamond coated tooling options, they provide the longest tool life and performance against abrasion and tool wear. Often, they are more cost effective in the long run due to their longevity, when compared to cheaper options that only save money in the short term.

Product image of a corehog square pcd diamond end mill
CoreHog PCD Diamond End Mill – Square

 

Product image of a Corehog ball nose PCD diamond end mill
CoreHog PCD Diamond End Mill – Ball Nose

In comparison to the cost of the part to be machined, the tool may be a fraction of the cost, making it worth spending the extra money to prevent greater costs that come with scrapping the part. Composite cutting tool manufacturer, CoreHog, stocks an array of PCD Diamond End Mills in Square and Ball Nose profiles.

Tooling Geometry

The geometry of a tool also plays a vital role in its machining capabilities of CFRP. There are many different geometry solutions, depending on your application, with different flutes, angle of cut approach, and profile. Corehog’s selection of CFRP Router Bits offer a great solution to your various CFRP needs.

Product image of a corehog cfrp router bit upcut burr style
CoreHog CFRP Router Bits – Burr Style – Upcut

Product image of a corehog cfrp router bit end mill upcut
CoreHog CFRP Router Bits – End Mill Style – Upcut

Product image of a corehog cfrp router bit drill point upcut
CoreHog CFRP Router Bits – Drill Point Style – Upcut

Understanding Machining Advisor Pro (MAP) 2.0

Machining Advisor Pro (MAP) was first introduced to the CNC Machining Industry in 2018 as a tool to quickly, seamlessly, and accurately deliver recommended running parameters to machinists using Helical Solutions end mills. then, thousands of users have utilized this cutting-edge resource, every day. In August 2022, a new and improved version of MAP was launched, optimized for Harvey Tool’s 27,000+ miniature and specialty cutting tools.

The following article is intended to introduce MAP 2.0 features. For more in depth information about MAP, including how to get started using it, please visit the original “In the Loupe,” post Get to Know Machining Advisor Pro.

New Map 2.0 Features

Addition of all Harvey Tool Products

With the release of MAP 2.0, users now have access to expertly tailored speeds and feeds parameters and recommendations to meet the exact demands of cutting tool and machine setup for all Harvey Tool products. This means that more than 27,000 Harvey Tool products are available in MAP and users can find their Specialty Profile Cutting Tools, Miniature End Mills, and Holemaking and Threading products to confidently use MAP generated speeds and feeds. With the addition of new products, there is now a new variety of operations to choose from, specific to the product selected.

New Strategy Option for Operations

Before the MAP 2.0 update, there were only two drop down menus for operation: type and toolpath. With the new update, there is an additional third operation drop down menu titled “strategy.” This option allows for users to further refine their machining operation, but only for certain tools that require it. For example, when using a Double Angle Shank Cutter on MAP, users can choose from a list of toolpaths including deburring, chamfer, or v-groove.

Once selected, users will choose a strategy for the toolpath – single side or double side engagement. The use of this feature gives the user more flexibility in their operations and saves time by automating their operation calculations. This feature is available for a variety of different toolpaths within the application.

MAP Offline Mode

With the release of MAP 2.0, and the addition of over 27,000 Harvey tools, users now can work offline. The work offline feature is only available for the new Harvey Tools. To access this feature, users can select the “User Account” button in the top right and start the process to allow MAP to work offline. Activating the work offline mode will cache the Harvey Tool data and takes around 15-20 minutes to complete before allowing the user to work offline.

Having the ability to use MAP offline can be useful when users are unable to connect to the internet as you will still be able to access MAP on a desktop or mobile app, whenever and wherever you need it.

Reduce Tool Chatter by Avoiding These 5 Boring Bar Application Mistakes

Boring bar applications are very popular in the lathe and CNC machining industry, as they provide a shop with extreme diversity and accuracy. Running a boring bar properly, however, is essential to ensuring you’re maximizing shop efficiency and achieving outstanding part finish. There are many mistakes that can be made when running boring bars and many that cause excessive machining vibrations or chatter that must be avoided. Learn the five mistakes that could be causing tool chatter in your boring applications and how you can stop chatter once and for all.

Lathe Boring Bar Application Mistakes

Using a Dull Cutter

Boring with a worn-out tool significantly increases cutting forces generated by the cut, leading to chatter. The more a tool is run, the more chance it has for galling, or in other words, built-up edge (BUE), making it imperative to inspect your boring bar before each application. BUE occurs when material is welded onto the cutting tool due to high friction and heat generation during a CNC machining operation. This condition is not desirable because it leads to poor tool life and increased vibrations due to an uneven cutting edge. Stocking your tool crib with great quality boring bars can help reduce BUE by providing a sharp, long lasting cutting edge, catered for your exact application. Learn other ways to reduce BUE in your turning applications, today.

Shows zoomed in effects of built-up edge and wear failure on carbide boring bar
Image Source: Carbide inserts Wear Failure modes. | machining4.eu, 2022

Utilizing Incorrect Speeds & Feeds

Like many applications, using improper turning speeds & feeds can lead to poor performance. In boring applications, using too high of a chip load can cause deflection, greatly increasing the chances of tool failure. Using too low of a chip load doesn’t allow the tool to cut enough, which causes the tool to bounce off the material, leading to increased tool wear and poor part finish. Discovering the right balance for using chip load is crucial in order to produce a more efficient cut.

lathe turning speeds and feeds

When running a boring bar, it is imperative to use the speeds & feeds recommended for the tool being used. Micro 100 provides downloadable and printer-friendly Speeds & Feeds for all Standard and Quick Change Micro-Quik turning tools.

Lacking Workpiece Support

A main cause of chatter in boring applications is lack of support on the workpiece. If a workpiece is not properly supported when entering a boring application, the tool will begin to chatter. Not only is it essential to confirm the proper workholding device is being used, but it’s also important to ensure that your setup is as rigid as possible. Learn more about workholding styles and considerations to make sure you’re supporting your workpiece properly in your next boring application.

Uneven Tool Holding

Similarly, tool holding also plays a vital role in the performance of a boring bar application. It is important to select a tool holder that accommodates the tooling being used and is as rigid as possible. Using an improper method of tool holding can lead to tool runout, which occurs when the tool or holder deviates too far off its axis.

Micro-Quik tool holder with a tool inserted and pointing towards workpiece
Image Source: @abom79

Many machinists opt for tools that promote machining efficiency by boosting the speed at which tool changes occur. For example cutting tool manufacturer Micro 100 offers Micro-Quik Holders, which offer unmatched rigidity, axial and radial repeatability, tip-to-tip consistency, and part-to-part accuracy in tool changes totaling fewer than 30 seconds.

Drilling an Improper Starter Hole

Before starting a boring application, drilling the proper hole is vital to ensuring that the boring bar has sufficient contact with the workpiece to properly stabilize the cut. If a hole is too large, the boring bar could deflect off of the workpiece. If the hole is too small, there will not be enough clearance for the tool, increasing chances of tool wear and possibly tool failure. When selecting a drill to prepare the workpiece for your boring applications, there are two dimensions that should be considered: the Head Width and the Minimum Bore Diameter.

Boring bar with line drawing showing where different dimensions are located on the tool

The Head Width, or “H” value on the above line drawing, is the actual width of the boring tool. The Minimum Bore Diameter is a calculated dimension slightly larger in size compared to the head with that is associated with the smallest drill size that should be used to start a boring application. It is recommended to opt for a drill that is the same or slightly larger than the Minimum Bore Diameter of the boring bar being used, to ensure there is proper clearance for the cutting edge.

Utilizing an Inefficient Coolant Strategy

If coolant isn’t aimed properly on the workpiece or if improper coolant is being used, tool life and quality part finish can be significantly reduced. Additionally, if coolant lines are aimed directly at the bore, the pressure of the coolant holds the chips in the bore, causing them to evacuate improperly. This then causes chip recutting, leading to chatter and finish problems. Opting for a Plumbed and Ported Tool Holder can mitigate this problem, ensuring chips are being properly evacuated out of the cut.

coolant being sprayed onto a part during a cnc machining operation

Machinists generally utilize Flood or High Pressure coolant methods for chip removal. Flood coolant uses low pressure to create lubricity and aid in chip evacuation. On the other hand, high pressure coolant delivers instant cooling of a part and quickly shoots chips away to prevent recutting.

Machining Nickel Alloys: Avoiding All-Too-Common Mishaps


Nickel-based alloys are growing in popularity across many industries such as aerospace, automotive, and energy generation due to their unique and valuable mechanical and chemical properties. Nickel alloys exhibit high yield and tensile strengths at low weights and have high corrosion resistance in acidic and high temperature environments. Because of these advantageous properties, nickel alloys have increasingly become popular in machine shops.

Unfortunately, nickel alloys have a reputation for creating issues at the spindle. These metals present themselves to be problematic as they easily work harden. Further, nickel alloys generate high temperatures during machining, and have gummy chips that can weld onto cutting tools, creating built-up edge (BUE). Fortunately, with the correct approach, one can be successful in cutting nickel alloys.

Work Hardening

Across machine shops, nickel alloys are notorious for being difficult to machine. This reputation stems, largely, from work hardening, or a metal’s microhardness increasing due to the addition of heat. According to the Nickel Development Institute, this heat is generated through friction and plastic deformation of the metal. As the metal is cut, the friction between the cutting tool and workpiece generates heat which is concentrated around the cutting area.

Simultaneously, the metal is being physically worked. This means that as it is being machined, it is experiencing plastic deformation, which is a physical property that measures how much a material can be deformed to the point that it cannot return to its original shape.

This physical working of a nickel alloy increases its hardness faster than it does most other metals. The combination of high heat generation and physical work quickly increases the alloy’s hardness, causing tools to dull quickly and fail. This may result in scrapped parts and broken tools.

8 flute HVNI End Mill for Machining Nickel Alloys
Shown above is Helical Solutions’ End Mill for Nickel Alloys. This tool, engineered to excel in Inconel 718 and other nickel-based superalloys, is fully stocked in 6 and 8 flute styles.

Tool Adhesion

As nickel alloys are being machined and heat is generated, chips tend to become stringy and weld themselves to a tool’s cutting edge. This phenomenon, built up edge or BUE, rounds the cutting edge of the tool, resulting in poor cuts and increased friction, thus further contributing to work hardening. An example of BUE is seen in the image below.

Zoomed in display of built-up edge on End Mill Flutes
On the above tool, chips from the workpiece (Inconel 718) have welded onto the cutting edge, severely decreasing the tool’s effectiveness. Image Source: International Journal of Extreme Manufacturing

Built-up edge also speeds up tool wear, as the rotational forces involved in the cut increase. Now that the cutting edge is rounded from welded chips, a blunt tool is being forced into the workpiece.

With a blunt edge, the cutting motion changes from a shearing action to plowing. In other words, instead of cutting through the metal, the tool is pushing the material, resulting in poor cuts and increased friction.

Excessive Heat Generation

With poor cutting, internal heat of the tool rises, which can cause thermal cracking, defined by cracks that form perpendicular to the cutting edge. The fractures within the tool are created by extreme internal tool temperature fluctuations.

As a cutting tool rapidly overheats while cutting nickel alloys, cracks may form which can lead to catastrophic tool failure. With high temperatures, galling may also occur, which is characterized by pieces of the tool flaking off due to the same adhesion that causes BUE. As the tool is being welded to the workpiece and the machine continues to rotate it, pieces of the tool may start to break off resulting in tool failure.

Overcoming Nickel Alloy Difficulties

Temperature Control and Coolant Usage

The first step to effectively machine nickel alloys is to keep temperatures manageable as the workpiece is cut. Using high pressure coolant is mandatory. Coolant pressure should be 1000 psi or greater. This high pressure concentrating on the cutting zone of the workpiece will dissipate heat within both the cutting tool and workpiece. By doing so, the chances of work hardening lessen.

High pressure coolant will also aid in clearing out chips from the cutting area. Those hot gummy chips are responsible for BUE. Removing them as quickly as possible reduces the risk of BUE forming on the cutting edge. Additionally, chip removal is important to avoid chip recutting.

Chips absorb much of the heat and often work harden themselves. Recutting these hardened chips will dull the cutting edge resulting in poor cuts and decrease tool life. In general, water-based cutting fluids are preferable as they have higher heat removal rates and have a lower viscosity, which is needed for high metal removal operations.

Using the Proper Techniques

To also assist with heat removal, utilize climb milling techniques, where possible. When climb milling, the chip thickness is at its maximum at the beginning of the cut and tapers off until the cut is complete. Due to this, less heat is generated, as the cutting tool does not rub on the workpiece. Most of the heat from the cut is transferred into the chip.

Selecting the Proper Tooling and Coating

The next step is selecting the right end mill. Your end mill of choice should have a proper tool coating, such as Helical’s Tplus coating. Tool coatings are specifically engineered to improve tool performance by reducing friction, increasing tool microhardness, and extending tool life.

Next is selecting flute count. Tools used for nickel alloys need to be rigid to withstand the cutting forces present when machining high hardness alloys. Therefore, higher flute counts are necessary. If using traditional roughing toolpaths, your end mill should have at least 6 flutes. With 6 flutes, there is sufficient flute valley depth to allow for chip evacuation, while having a larger core diameter keeps the tool strong and rigid.

For finishing operations and instances of implementing high efficiency milling, higher flute counts should be considered. A tool used this way should have 8 flutes to provide excellent surface finish.

Helical’s End Mills for Nickel Alloys

CNC tooling manufacturer Helical Solutions’ End Mills for Nickel Alloys product offering, its HVNI tool family, specializes in machining nickel alloys as it exhibits these key tool features.

Four Helical Solutions End Mills for Nickel Alloys positioned over a Helical product container
The tools shown above are Helical Solutions’ End Mills for Nickel Alloys. These tools are coated in Tplus for high hardness, resulting in improved tool life and increased strength,

With its Tplus coating and variable pitch to minimize chatter, these solid carbide end mills are engineered to perform in all grades of nickel alloys. Coupled with their geometry to maximize cutting performance, Helical’s End Mills for Nickel Alloys utilize faster speeds and feeds, which are readily available on the Helical Solutions website and Machining Advisor Pro.

For more information about the chemical make-up, uses, and categorization of nickel alloys, read “In the Loupe’s” post “Understanding Nickel Alloys: Popularity, Chemical Composition, & Classification”.

4 Key Benefits of Combination Feed & HEM End Mills

Designed to conquer machine limitations and other common machining issues, combination and multifunctional tooling are highly coveted by machinists. These tools often integrate multiple geometries and flute designs to tackle wider varieties of machining applications with the same tool. This means fewer tools and tool changes are needed within a job, reducing complexity and increasing shop flexibility.

Taking these Issues and limitations into consideration, Harvey Performance Company’s Engineering Team went to work to design a new series of end mills referred to as Helical Solutions’ Combination High Feed & HEM End mills. This product series offers a feature set that will solve the four common issues listed below along with a few other issues that machinists commonly experience in the spindle.

For most shops, machine limitations cause longer, costlier, and more complicated jobs. If you are reading this article, you may know exactly what we are talking about. Machinists have a job that needs to be completed and end up having to add another operation. They find themselves improvising on tooling to complete an operation. This is because their machine has a limited number of tool stations, less than adequate horsepower, or several other limitations. Many times, this will impact operations in a negative way by increasing overall cost or reducing the quality of parts. As the name suggests, Helical’s Combination Feed & HEM tooling has been designed to excel in both applications without requiring a tool change. The end profile is non-center cutting for high feed applications, while the offset chipbreaker OD geometry excels in high efficiency milling strategies.

Helical Solutions Combination Feed & HEM end mill

How This Tool Addresses Machine Limitations

A common issue present in a fair number of shops is a limited number of tool stations available. The Combination Feed & HEM products afford the ability to do multiple roughing and finishing operations with one tool, using only one tool position. This eliminates the need to try to blend tools or control multiple offsets in your machining operation.

A second machine limitation that may affect your tool choice is you machine horsepower. The high feed end geometry and the chipbreaker OD geometry are both designed to reduce the amount of power required. This opens up new opportunities within light duty and low horsepower machines, offering more flexibility to your shop.

Cut Down Part Cycle Times

In a shop, long cycle times negatively impact productivity and machine availability. As the manufacturing industry becomes more competitive and as jobs become more demanding, the need for reducing cycle times becomes even more important.

The Combination Feed & HEM End Mills allow the use of both High Feed and High Efficiency milling strategies that provide high metal removal rates in your operations.  Increased material removal rates lead directly to reduced cycle times, plus the versatility of these tools helps to avoid time-consuming tool changes.

Click Here to Watch Helical’s Combination Feed & HEM Mill Be Pushed to the Limits

Limiting Complexity and Increasing Ease of Use

With today’s machined parts growing in complexity, programming can become cumbersome with multiple machining strategies and many tools required.  Finding ways to reduce the complexity of programming can help an entire job run smoother through your shop.

These Combination Feed & HEM End Mills provide an increased ease of use. This gives you the ability to conquer multiple operations with one tool. This eliminates the need to program and set-up multiple tools, boosting productivity

Helical Solutions Combination Feed & HEM end mill laying over a product container

Cutting Down on Costs

Another common issue is the cost of purchasing tooling. The Combination Feed & HEM End Mills offer a feature set that allows the consolidation of tooling and operations. Reducing the number of different tools needed for your application can reduce the overall cost of your operations substantially.

Feed/HEM Product Capabilities and Application Areas

Helical’s Combination Feed & HEM End mills are designed to tackle a broad range of demanding operations in a wide variety of steel types. As these products were engineered to solve machine limitation issues, the end geometry excels across a variety of operations. These include High-Feed milling operations, machining bores, closed or open pockets, internal or external contours, etc. The peripheral geometry was engineered with flexibility in mind. This allows the use of an HEM (High Efficiency Machining) toolpath to achieve high metal removal rates while maintaining great chip control as well as most traditional roughing and finishing strategies.

Helical Solutions Combination Feed & HEM end mill laying over a product container

The versatility of these tools can be easily illustrated with a long list of applications:

  1. High efficiency milling
  2. High feed slotting
  3. High feed roughing
  4. Milling in open and closed pockets
  5. Internal and external profiling
  6. Helical ramping and interpolation
  7. Rough and finish profile milling
  8. Offset plunge milling in slots and deep pockets
  9. Traditional roughing operations
  10. Contouring and profiling operations

Commonly, machinists would need a range of specialty tooling to complete different aspects of a job. This requires long cycle times, and higher costs when all the necessary tools are considered. As most shops suffer from a limited number of available tool stations, combination mills aid in alleviating this pressure. These tools are designed to excel and conquer.

Conquer Machine Limitations and Shop Issues

Helical’s Combination Feed & HEM End Mills were designed with versatility in mind. The major benefit of these tools is addressing machine limitations and the common issues presented above. These tools will provide you with a feature set that will allow you to combine operations, reduce cycle times, reduce cost, reduce scrap, and expand your machines capabilities. Let Helical impress you with the Combination Feed & HEM line of end mills.

How to Adjust Running Parameters for Miniature Tooling

High precision machining is a subset of subtractive manufacturing that has grown in popularity over the years, especially as industries like medical, dental, mold tool and die, and semi-conductor manufacturing grow. Some jobs can call for extremely small diameters (down to even .001”) and ultra-precise tolerancing. With tooling this miniature, machinists must utilize different machining practices than they otherwise would, as common issues that would arise with larger end mills are magnified within miniature tooling applications.  Speeds and feeds become critical to ensure your tool survives the job.

Three Miniature Tools sitting over a page of a dictionary

Where Breakage Occurs with Miniature Tooling

When breakage happens with miniature tooling, it’s important to determine where on the tool the breakage is occurring. Breakage points are sometimes quite difficult to see with such small tooling. Finding the location, when possible, helps to diagnose the issue. For example, if the breakage occurs along the length of cut, there could be chip packing. If chip packing is the issue, it’s helpful to decrease the feed rate and lower the depth of cut per pass. If the tool breaks on the transition angle toward the shank, this could be due to a few things. The first instinct should be to check the runout of the tool. Runout should be measured at less than .0001”. In this case, check tool set up to ensure that the tool is stable within the tool holder. Another issue could be excess pressure on the tool caused by high pressure coolant or even deflection. Deflection occurs when the cutting pressure causes the tool to bend slightly – in this case, the tool will break at its weakest point. To minimize the opportunity for deflection, ensure the tool is the largest diameter and shortest length of cut possible for the job.

Miniature tooling sitting over a dime

Tips for Avoiding Future Breakage

There are a few different points of interest to focus on to prevent tool breakage.

The Right Tool

 Determining the correct end mill is the necessary first step toward preventing breakage. Choosing a material specific end mill is preferred, especially with the more difficult to machine materials. Harvey Tool’s material specific tools have different geometries and coatings for different materials. For example, our aluminum specific end mills have a variable helix of approximately 42 ° whereas the high temperature alloy specific end mills we offer have a variable helix of about 34°. A tool with an odd number of flutes or a variable helix or pitch also helps to avoid chatter that could lead to breakage in the machining process. Approaches also change depending on the application. With slotting for example, rigidity is critical for success, therefore a tool with the most flutes possible is recommended.

Tool Set Up

The smaller the tool, the more fragile it is. Therefore, proper handling before and during set up is critical. It is key to keep tooling in the original packaging if it is not in the machine and covering the tip when positioning the tool in the tool holder. Determining coolant for miniature tooling is also critical to ensure that high pressure from the coolant doesn’t cause damage of the tool. High pressure coolant directly to the tool almost always causes some form of breakage. For this reason, high pressure coolant is not recommended on the smaller end of the miniature tooling spectrum. In this case, flood coolant is the recommended approach.

Miniature Tooling Running Parameters

Running speed of an end mill is determined based on the tool diameter, so the smaller the tool, the faster the RPM. To ensure best tool life, it is crucial to run the smaller end mills at the recommended parameters.

Harvey Tool speeds and feeds charts list recommendations for SFM, chip load and depth of cut based on the cutting material, tool diameter and cutting application. To calculate speeds and feeds using Harvey Tool speeds and feeds charts, follow the following formulas and our recommended parameters:

Note*: There are often limitations with the machines used for these tools. One of the most asked questions about our speeds and feeds for miniature end mills is how to adjust for this quick speed. We recommend setting the RPM at something the machine can handle (or the fastest the customer feels comfortable with) and keep the feed rates and depth of cut the same.

Choosing depth of cut parameters for miniature tooling is extremely important based on the application. For example, finishing parameters often have a much higher speed and feed rate than slotting or roughing parameters but the depth of cut passes are much smaller. This enables the tool to run such high parameters without breakage as there is less contact with the workpiece.

zoomed in miniature tooling

Using miniature tooling can be a little bit intimidating if you’ve never used it before. Issues that arise with larger end mills tend to be amplified with smaller tools. It is very important to have the right end mill for the application. Speeds, feeds, and depth of cut are also essential in proper cutting. With smaller tooling comes higher speeds. Always follow manufacturer recommended speeds and feeds, lowering the speed when necessary to accommodate machine capabilities. Lastly, if breakage does occur, be sure to find where the break is to help diagnose the issue.

PVD Coating vs. CVD: Two Common Coating Application Methods

Most tool manufacturers offer tool coatings, made up of a layer of metal compounds adhered to the surface of the tool to enhance its performance. The most common methods for adding coatings to a tool are Physical Vapor Deposition (PVD coating) and Chemical Vapor Deposition (CVD coating). This article will take a deep dive into PVD vs CVD to identify their unique and shared characteristics.

Physical Vapor Deposition (PVD) Coatings

The PVD coating method is a process in which metals go through a cycle of vaporization and condensation to be transferred from their original solid state to the tool. The metal compounds that make up the coatings are often referred to as the “metal material” in this process. The metal material starts as a solid wafer and is vaporized into a plasma, which can then be put onto the tools in the chamber. In this process, the tools are referred to as the “substrate.”

There are two different ways in which PVD coatings can be performed: arc ion plating and sputtering.

Arc Ion Plating & Sputtering

Key Differences

The main difference between arc ion plating and sputtering is that arc ion plating uses high electrical currents to vaporize the metallic material, and the metal ions are steered onto the tool for coating. Sputtering, in contrast, uses the properties of magnetic fields to direct reactive gasses to collide with a target made up of metallic material. During these collisions, metallic surface ions fall from the target and land on the substrate, slowly bombarding it until it is sufficiently coated. Both arc ion plating and sputtering are high temperature, ultrahigh vacuum processes. The term “vacuum” refers to any pressure below atmospheric pressure at sea level.

Three Harvey tool AlTiN coated end mills
Above is an example of a Harvey Tool AlTiN Coated tool, which is applied using a PVD process.

Application Processes of Arc Ion Plating & Sputtering

Arc Ion Plating

  1. The internal pressure within the reaction chamber is dropped to form a vacuum to around 1 Pa (0.0000145 psi). Creating a vacuum is crucial as it removes any moisture and impurities, on or surrounding the tools.
  2. The chamber is heated to temperatures ranging from 150 – 750°C (302 – 1382°F). The temperature of the chamber is dependent on the coating that is being applied to create an ideal chemical reaction and adhesion between the plasma and substrate. A high current of around 100 A is applied to the metallic material causing an explosive reaction.
  3. The high current positively ionizes the metal and vaporizes it into a dense plasma.
  4. The substrate is negatively charged to attract the positive metal ions.
  5. The ions collide into tools with force and are deposited, forming a film that builds up in thickness to create the desired coating.

Sputtering

  1. The internal pressure within the reaction chamber is dropped to form a vacuum to around 1 Pa (0.0000145 psi) to remove any moisture and impurities on or surrounding the tools.
  2. An inert gas is pumped into the chamber to create a low pressure atmosphere. Inert gases are specifically used, as it is non-reactive with the metal elements and ensures that impurities are not mixed in with the tool coatings.
  3. The gas used is dependent on the atomic weight of the metal material; a heavier gas is commonly used with heavier metals.
  4. The chamber is heated to temperatures anywhere from 150 – 750°C (302 – 1382°F) depending on the coating that is being applied.
  5. The tools are placed between the metallic materials (called the “target” in sputtering) and an electromagnet, so that when turned on, a magnetic field runs along and around the tools.
  6. A high voltage is then applied along the magnetic field ionizing the argon atoms.
  7. Voltage ranges from 3-5 kV, and if using AC, with a frequency of around 14 MHz.
  8. The target is negatively charged attracting the positively charged Argon gas.
  9. The inert gas collides with the target ejecting metallic compounds onto the substrate to create a coating.

Key PVD Coating Differences, Summarized

Arc ion plating and sputtering are both effective methods of applying a PVD coating. So why use one over the other? Arc ion plating has a significantly higher ionization rate than sputtering, allowing for much faster deposition rates, shortening coating times. In turn, since sputtering is a slower process, it allows for more control when applying multi-metal compositions and ensuring that the stoichiometry of the coating is even throughout the tool. Finally, during the PVD coating process, micro-droplets are formed as the vaporized metals condense and solidify onto the tools. As these droplets impact the newly applied coating, they can cause defects and craters, producing residual stress points. In order to achieve a perfect coating, droplet size must be minimized. Arc ion plating produces droplets up to 3µm (micrometers) in diameter, while sputtering has droplets with diameters up to 0.3µm. With droplets up to ten times smaller, sputtering produces much smoother and defect-free surfaces which have been proven to slow corrosion rates.

Chemical Vapor Deposition (CVD)

Harvey tool CVD ball end mill held in person's hand
Above is an example of a Harvey Tool CVD Ball End Mill.


Unlike PVD coating operations, which use high electrical charges and atomic collisions to deposit coatings onto a tool, the CVD method utilizes the chemical properties of the metals to transfer metallic compounds onto the tool. The following steps are required to carry out the CVD operation:

  1. Much like the PVD method, the first step is creating an ultrahigh vacuum within the reaction chamber of around 1 Pa (0.0000145 psi) to eliminate all moisture and impurities.
  2. The internal temperature of the chamber is increased between 600 – 1000°C (1112 – 2012°F).
  3. The temperatures required in the CVD process are significantly higher than PVD coating because this method requires a chemical reaction to occur between gases flowed into the chamber and the substrate. High temperatures are required to initiate and maintain these reactions.
  4. Once the substrate is heated to its desired temperature, the metals intended to be coated onto the tools, which are already in their vapor state, are chemically bonded with a reactive gas (typically chlorine), and flowed into the chamber.
  5. The metallic materials being bonded to a gas keeps it in a gaseous state while it is being transported through the chamber and around the tools.
  6. Hydrogen gas is then pumped into the chamber and mixes with the chlorine and metals.
  7. When this mixture meets the heated substrate, the thermal energy creates a reaction where hydrogen and chlorine bond and leave the metallic materials behind on the tools.
  8. In the chamber, there is an exit vent where the waste gas (H2Cl) is removed.

PVD Coating & CVD Coating, Summarized

Tool coatings are utilized by machinists every day to accomplish prolonged tool life, a more efficient machining operation, and an overall higher quality final part. Most manufacturers use two different types of application techniques, PVD coating and CVD coating. Stay on “In the Loupe” to learn more about tool coatings by reading the following blog posts: Overview of Harvey Tool Coatings: Maximizing Performance and 3 Ways Tool Coatings Increase Tool Life.

Citation:
[1] Ucun, İ., Aslantas, K., & Bedir, F. (2013). An experimental investigation of the effect of coating material on tool wear in micro milling of Inconel 718 super alloy. Wear, 300(1-2), 8–19. https://doi.org/10.1016/j.wear.2013.01.103

Titan USA Carbide Drills: Jobber, Stub, & Straight Flutes

When navigating Titan USA’s offering of carbide drills, it is imperative to understand the key differences among the three carbide drill styles: Jobber Length, Stub Length, and Straight Flute Drills. The right drill for your application depends on, among other factors, the material you are working in, the job requirements, and the required accuracy.

PRO TIP:

Chip evacuation can be an obstacle for hole making. Pecking cycles can be used to aid in chip removal. Peck cycles are when the drill is brought in and out of the hole location, increasing depth each time until the desired depth is reached. However, pecking cycles should only be used when necessary; this process increases cycle time and subjects the tool to added wear from the repeated engaging and disengaging.

Jobber Length Drills

Titan USA jobber length drill

A carbide Jobber Length Drill is the standard general-purpose drill within Titan USA’s offering. It has a long flute length and an included angle of 118o. These drills are great for general purpose drilling where the tolerances are not as tight as the Stub Drill or Straight Flute Drill. Due to the length of these drills, however, they will be more affected by any lack of rigidity in the set up and can have higher runout, or straying from a desired location, during the drilling operation.

PRO TIP:

To achieve high accuracy and great finish, consider utilizing a Reamer. Reamers are designed to remove a finite amount of material but bring a hole to a very specific size. To do this, first drill 90% – 94% of the desired hole diameter with a Jobber Drill. After 90% – 94% of the material is removed, go in for a finishing pass with a Reamer. Reaming tools are highly accurate and leave a beautiful finish.

Stub Length Drills

Titan USA stub length drill

Titan USA carbide Stub Length Drills have a shorter flute length, wider included point angle, and a significant drop in helix angle, when compared to Jobber Length Drills. The shorter length and wider tip create for a more rigid tool and, in turn, more accurate holes. The stub drill is the best option when drilling with tight tolerances on shallower holes.

Straight Flute Drills

Titan USA straight flute drill

Carbide Straight Flute Drills have the smallest core of the three drill types mentioned within this post. Titan USA offers Straight Flute Drills with 2 flutes and a 140o included angle. These drills are designed for hole making in materials that create short chips. Materials in which the Straight Flute Drill typically performs best include cast aluminums and cast irons, as well as copper. In addition, this type of drill can work very well in high hardness materials, but the core diameter should first be adjusted to accommodate the increased hardness. For these difficult to machine materials, casting the part with a core hole and then opening it up with the Straight Flute is a great option. This removes some of the stress caused by chip removal and allows for the drill to do what it does best.

Chip removal can be more difficult in this style of carbide drill because the chips are not guided along a helix. With helix flutes, the motion of chip removal is mostly continuous from their initiation point, through the flute valleys, and finally out of the flute valleys. The helix creates a wedge which helps push the chips along, but the straight flute does not have that. It interrupts that natural turning motion created by the drill face which can affect chip evacuation. Due to the interruption in motion this type of drill is better suited for applications involving chips of smaller size.

PRO TIP:

Helix drills create multiple different forces on the part, which can create micro imperfections. The Straight Flute Drills do not create those forces, so the finish is much more consistent down to the micro level. The margins of the Straight Flute Drill also burnish the inside of the hole as they spin, which improves the finish as well. When comparing the Straight Flute Drill to a helix drill, the length of the overall contact point is much shorter in the Straight Flute Drill, and has less heat generation. The decreased heat will also reduce the probability of work hardening.

Selecting Your Perfect Titan USA Carbide Drill

Selecting the correct carbide drill for your application is a crucial step in hole making. The Jobber Drill is a great general-purpose drill and should be utilized in applications requiring long reach. The Stub Drill increases the rigidity with its shorter length of flute, allowing it to drill with higher accuracy. Applications which involve tight tolerances and more shallow holes can be done with the Stub Drill for high-quality results. Lastly, for difficult to machine and hard materials, the Straight Flute Drill is the perfect solution. When the core diameter and chip evacuation is properly addressed, the Straight Flute Drill produces beautifully consistent surface finish and extremely tight tolerances. Similarly, Titan USA offers its carbide drills in both an uncoated option, and AlTiN coating. Traditionally, uncoated tools are general purpose workhorses in a wide variety of materials both ferrous and non-ferrous. AlTiN or Aluminum Titanium Nitride is an enhanced coating specifically made for ferrous materials that extends tool life and performance across a wide range of steels and their alloys.

For more information on Titan USA Drills, and to view its full selection, click here.