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Technical Blog excerpt courtesy of Techniks USA  Techniks offers the broadest selection of ER collets including standard, steelsealed, coolant, rigid & floating tap, and DNA - Dead Nuts Accurate, collets. It is important to understand how collets work, what impacts their performance, how to maintain collets for long service life, and how to recognize when to replace them. Collets are a high-precision wear component of a tool holding system and require maintenance to ensure accuracy. First, it’s important to remember that collets are the softest component in a collet-based tool-holding system assembly and are designed to wear out. Here is an overview of the wear pattern of a collet-based tool-holding system. The machine spindle is harder than the tool holder/collet chuck that fits into the spindle, so any wear between these two components will mostly occur to the collet chuck. That’s good. It protects the spindle from expensive maintenance. Collets are softer than both the collet chuck body and the cutting tool, so any wear forces between these items will mostly occur to the collet. Since collets are generally the least expensive component in a collet chuck tool holding system, it is preferred that the collets wear out before the other components. Worn-out collets will not achieve the same level of accuracy and rigidity that newer collets can provide. The result is more chatter when cutting workpieces, less accuracy, and shorter cutting tool life. When to Replace ColletsCollets are designed to wear out as they lose accuracy and rigidity with use. High side-load forces during milling operations cause cutting tool deflection as illustrated below.  Over time, these side-load forces will bell-mouth the collet at its face.  As the collet experiences bell-mouthing, the cutting tool is allowed to deflect more and more during milling operations. Unfortunately, the collet may still indicate good accuracy on a presetter where there are no side-load forces. However, once the tool is put into service and begins experiencing side-load forces, the cutting tool is allowed more room to deflect, resulting in increased chatter and reduced tool life. It is recommended to change collets out every 4-6 months, depending on usage, to ensure the most rigid and accurate collet chuck assembly. A good rule of thumb is to replace collets every 4-6 months to maximize the performance of your tooling. Again, collets are designed to wear out and are generally the least expensive component in the system. It is much less expensive to replace the collets as opposed to prematurely wearing out cutting tools. The following tips will help you in maintaining collets:
Signs that Your Collet Should be Replaced
If you see signs of fretting on the collet, it is advised to replace the collet. You should also ensure that collet nuts are tightened to the correct torque specifications during setup.
CLICK HERE to see all of our more in-depth articles on FRETTING to learn more.
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 The L:D ratio of a tool assembly is calculated by using the length of the bar (or body) of a tool assembly and the diameter of the tool, not the workpiece bore diameter and depth.
To expand on this concept, we see in the first configuration below the Ø16mm bar is sticking out 160mm which is a 10:1 although the bore is only a 2.5:1. In some applications this extra reach is needed to get around a fixture or a feature of the part. However, in those cases where it is not needed, decreasing the overhang by 55mm means the new L:D of 105:16 is 6.5:1. This alone would represent approximately 10x increase in cutting speed by increasing from 20mm/min vs. 200mm/min. The use of modular reductions has also been found to be a good strategy to improve tool performance. Comparing the lower two assemblies below, the middle assembly uses the same connection size for the length of the tool, ignoring the larger access diameter, and results in a 6.4:1 ratio. When a shank with a larger connection size is used along with a modular reduction, the ratio is halved, and provides a 350% productivity improvement (14mm/min to 50mm/min). In all cases, reducing the L:D ratio provides an improvement in speed which then provides longer tool life, better surface finish and size control of the bore. by Frank Twomey | OSG USA By switching to the AE-TL-N, Ross Industries has reduced about 75 percent of cycle time on the upper chambers and is now on average achieving a 150 percent cycle time reduction on other aluminum parts.  AE-TL-N DLC Coated Carbide End Mill Drives Greater Efficiency in Aluminum Part Processing Founded in 1968, Ross Industries, Inc. is a specialist in food processing and packaging solutions. Some of its key products include meat tenderizers, antimicrobial intervention systems, chilling and freezing equipment, formers and presses, slicers, macerators, tray sealing equipment, and more. All Ross systems are designed to help processors streamline food manufacturing and packaging functions to improve quality, productivity, and food safety while minimizing waste. With more than 50 years of industry expertise, Ross Industries has built an international reputation as one of the world’s finest food processing and packaging system providers. Employing approximately 100 staff, Ross Industries’ manufacturing plant is located in the city of Midland, Virginia, USA, with an estimate production area of 80,000-square-feet.  Founded in 1968, Ross Industries, Inc. is a specialist in food processing and packaging solutions. Employing approximately 100 staff, Ross Industries’ manufacturing plant is located in the city of Midland, Virginia, USA, with an estimate production area of 80,000-square-feet. Recently, Ross Industries was tasked with reducing cycle times on all of its aluminum parts. OSG Territory Sales Manager Frank Twomey has been in touch with Ross Industries through a distributor for about two years ago. In need to optimize productivity, OSG was given with an opportunity to test cut the upper chamber 6061 aluminum alloy part used in Ross Industries’ tray sealers for food packaging.  A CAD model of the front & back of the upper chamber, a part used in Ross Industries' tray sealers for food packaging Ross Industries has been producing these aluminum upper chambers for more than 25 years. Approximately 80 chambers are made annually along with thousands of other aluminum parts. The upper chambers are machined using a Doosan HM 1000 horizontal machining center with CAT-50 spindle taper.  The upper chambers are machined using a Doosan HM 1000 horizontal machining center with CAT-50 spindle taper Ross Industries was originally using a competitor 1.5-inch diameter indexable shoulder cutter for the application. The competitor tool was used at a speed of 6,000 rpm (2,358 sfm, 717.8 m/min), a feed rate of 120 ipm (3,048 mm/min), 0.005 ipt (0.127 mm/t), 0.3-inch (7.62 mm) radial depth of cut, 0.375-inch (9.525 mm) axial depth of cut, and at a metal removal rate of 13.5 inch3/min (221.2 cm3/min).  The upper chambers are made of 6061 aluminum alloy Upon a detail evaluation of the application, Twomey recommended OSG’s 3-flute 1-inch diameter AE-TL-N DLC coated square end mill (EDP# 86301809). The AE-TL-N DLC coated carbide end mill is extremely effective for non-ferrous materials such as aluminum alloys that require welding resistance and lubricity. With excellent cutting sharpness, it is able to suppress burrs to achieve superb surface finish. The AE-TL-N features a unique flute form to enable trouble-free chip evacuation and a large core design for high rigidity to prevent chattering. Its center cutting edge configuration enables the tool to be used for plunging. Furthermore, with the addition of OSG’s DLC-SUPER HARD coating, long tool life can be achieved. This end mill series is available in square, sharp corner edge and radius types to accommodate a wide range of applications.  The AE-TL-N DLC coated carbide end mill was tested at a speed of 5,125 rpm (1,343 sfm, 408.7 m/min), a feed rate of 231 ipm (5,867 mm/min), 0.015 ipt (0.382 mm/t), 0.14-inch (3.556 mm) radial depth of cut, 1.62-inch (41.148 mm) axial depth of cut, and at a metal removal rate of 52.39 inch3/min (858.5 cm3/min). Cycle time on the upper chambers went from 34.5 hours to nine hours. By switching to the AE-TL-N, Ross Industries has reduced about 75 percent of cycle time on the upper chambers and is now on average achieving a 150 percent cycle time reduction on other aluminum parts.  Switching to the AE-TL-N DLC coated carbide end mill, cycle time on the upper chambers went from 34.5 hours to nine hours. “This end mill creates chips so fast that our machines chip conveyors couldn’t keep up,” said Ross Industries Machine Shop Manager Greg Williams. “We had to speed up the conveyors.” Taken in consideration of factors such as tool change time, machine cost, labor, etc., it is estimated that an annual cost savings of $183,000 can be gained. In addition to the upper chamber part, Ross Industries has also converted all of its aluminum end mills to OSG’s AE-TL-N series in various sizes.  From left, Ross Industries Machine Shop Manager Greg Williams and OSG USA Territory Sales Manager Frank Twomey pose for a photograph with a completed upper chamber. “With the performance and consistent tool life of the AE-TL-N we are able to run these tools lights out,” said Williams. “In some cases, it is able to achieve as much as four times the metal removal rate versus the competitor tool.”
For more information on OSG’s AE-TL-N DLC coated end mill for non-ferrous materials and Ross Industries Technical Blog excerpt courtesy of Techniks USA Collets come in many different types and sizes. Here is an overview of three of the more popular types of collets, along with the pros and cons of each system. ER Collets ER collets have between a 0.020” and 0.040” holding range The ER collet system has become very popular due to the flexibility of the system to hold a variety of cutting tool shank types including drills, end mills, and taps. Also, ER collets provide several solutions for increasingly popular coolant-through cutting tools. Most standard ER collets have between a 0.020” and 0.040” holding range, making them a good choice when needing to hold odd-sized cutting tool shanks. This holding range also means fewer ER collets are required to hold a range of cutting tool shank diameters as opposed to other collet systems like TG. The popularity of the ER collet system has led to several variations to hold a wide assortment of cutting tool shanks. Some ER collets have been modified with squares at the bottom to hold taps. Others have been modified to provide quick-change capabilities or compensation, also called “float”, for rigid tapping cycles as shown in the images below. Specialized ER ColletsOther modifications include special slotting designs that seal around the cutting tool shank and force coolant through channels in coolant-through tooling, as well as modifications to include coolant ports in the collet that direct coolant to the cutting area. TG Collets TG collets have about the same accuracy as DA collets, but because there are more slots, and therefore more faces clamping on the cutting tool shank, they tend to deliver greater holding power. TG can be a good solution for larger shank diameter cutting tools, but they generally limit how far down into a pocket you can reach due to interference with the collet nut, as TG collet nuts tend to be quite large. TG collets are not as popular as ER collets for several reasons. Most notably, the larger diameter collet nuts can require the use of extended end mills to avoid interference from the collet nut when milling pockets. Also, since TG collets have a very small collapse range, they are intended for use with one size cutting tool shank. ER collets, by contrast, offer a large collapse range that can be helpful when clamping odd-shank diameter tools. On the flip side, TG collets tend to have a bit more holding power than ER collets due to the collet base having a 4° taper as opposed to the 8° taper found in ER collets. This can make TG collets a good choice when machining with longer-length cutting tools. Double-Angle (DA) Collets Please stop using DA collets in CNC Machining Double-Angle (DA) collets have been around for a long time and continue to be used in the market. There are, however, many issues associated with DA collets of which users should be aware.
Let's just clear the air and say it: Don't use them. If you have them in your shop, replace them with ER Collets and ER Collet Chucks as soon as possible and you will recoup the cost of the new holders and collets in your tool life probably within a month or two. One of the primary issues with DA collets is that they essentially clamp on the cutting tool shank with only two opposing faces in the I.D. bore. DA collets have four slots in the front of the collet and four slots in the back of the collet creating four clamping faces. However, when DA collets are tightened towards the lower end of their collapse range, two of the faces tend to be pushed out of the way so only two of the faces are clamping on the cutting tool shank. This may cause some runout at the nose when the tool is inspected in a presetter. Additionally, when the tool begins cutting and side forces are applied to the cutting tool, the cutting tool tends to deflect into the area where the faces are not clamping on the tool shank. This results in excessive chatter that dramatically reduces tool life and results in rough surface finishes. You will be hard-pressed to find a quality end mill holder manufacturer endorsing the performance of their tooling in DA collets.  Jergens has introduced its new Washdown Tool, which provides 360° of spray using coolant flow to wash away chips from exposed surfaces. The in-between-processes tool is programmed inline after a predetermined number of machining cycles. The Washdown Tool provides thorough chip removal from the many exposed surfaces inside the machining area. In turn, this saves time for operators by reducing the time spent cleaning chips from a machine interior, workpiece or workholding setup. The unit uses multiple spray nozzles on its circumference, providing a steady and pressurized stream. Each nozzle can be plugged or opened to create customized spray patterns. Added spindle rotation is said to ensure that coolant reaches virtually everywhere inside the machine. Residing in the tool changer, the Jergens Washdown Tool is deployed periodically at scheduled intervals. This automation shortens cleaning time and supports long machining cycles, even lights out manufacturing periods when no operator is present. Jergens Machine Washdown Tool is a cleaning tool attachment for machine spindles and fits 16mm Weldon holders. The user selects which outlets to open, which controls the pressure and direction of the jets. Moving and rotating the spindle under a constant flow of coolant achieves an excellent and systematic cleaning of the machine interior. Through the optional installation of a pressure gauge, the status of the pump, filter, and entire supply line can be checked. Product Specifications:
 A common question asked for boring operations is when would I use a ground chip-breaker vs. a molded chip-breaker? A ground chip-breaker is recommended for chip control issues. The high-positive rake angle will help to make shorter chips, and the chip groove orientation forces the chips forward to more easily evacuate them from the bore, especially when used with high-pressure coolant through the tool. Ground chip-breaker inserts also provide lower cutting forces, so they are better suited for deep-boring or long-reach applications, and other situations where part or tool stability may not be optimal. Ground chip-breakers are also recommended for tight-tolerance applications where stock allowance is typically light for the final size pass. A molded chip breaker is recommended for stable applications in short-chipping materials. Because these situations don’t require a super-sharp edge for cutting the material, these inserts hold their edge longer for better tool life, and in most cases are less expensive. A Primer on Types of Chips
by Peter Jacobs, via OSG USA blog There are almost as many distinct variations of CNC tools as there are finished products that could be milled. If you are familiar with the functions these tools perform, it will be much more straightforward for you to select the ones appropriate for the project you are working on. When it comes to the amount of time it takes and the quality of the work to be produced, choosing the appropriate cutting tool for your CNC milling machine, the material, and the type of milling can have a significant impact. So here is a list of prominent milling tools utilized for CNC cutting.  OSG HY-PRO® CARB VGM Series Different types of CNC milling tools make it feasible to achieve the highest level of product customization. While cutting into and shaping different types of materials, several tools are employed. The tool that should be utilized to cut also gets decided by the finalized design of the cut. Aside from these factors, specialists choose their tools based on how well they match the required speed with the desired finish. Depending on the ultimate purpose of the completed product, one of these two considerations might take precedence over the other. The top 7 milling tools for CNC cutting are: 1. End MillsThere are numerous kinds of end mills, each of which is designed for a particular kind of cutting. All end mills cut at an angle of ninety degrees. A center-cutting end mill is what's required to make a vertical cut. These mills can cut both the center and the margins of the workpiece. Non-center cutting end mills feature a hole in the middle of the tool and only contain cutting edges mostly along the ends of the mill. Since roughing end mills have fewer flutes than standard end mills, they are the tools of choice for making the initial cuts in a workpiece. You will need finishing end mills with additional flutes to obtain a design similar to the part you want to produce. It will enable you to deliver a component that is cut with immense precision. The tool employed on a project will vary depending on several factors, the most important of which is the number of flutes and the material of its composition. The production of end mills typically involves the use of cobalt, high-speed steel, and carbide as raw materials. More details about the different types of mills (as per their material) are given below.
End mills may perform a wide variety of cuts, the type of tool used depends on the type of cut being made:
2. Face MillsThis tool is primarily used to create a level surface on a solid portion of the material. As the first step in milling, this is often performed on the top of the stock to smooth it out. The cutter inserts in a face mill's sole body can be changed for specialized cutting tasks. You would require more cutters to remove metal at a faster rate. 3. Twist DrillsDrill bits resemble end mills in that they have a conical cutting tip on the end of a shaft with one or even more flutes. Twist drills are often made from solid carbide or High-Speed Steel (HSS). The drill's hardness, wear resistance, and lifespan can be improved by applying a gold-colored coating, such as TiN. 4. Fly CuttersFly cutters are considered the best to create a fantastic surface finish. The clockwise motion of these cutting tools produces a mirror-like finish on the material. 5. Center Spotting DrillsThese stocky tools first construct a precise conical hole to avoid the drill bit from drifting during a cutting operation and end up drilling the hole at an incorrect site. Screw clearance holes and counterbores can be drilled with the same tool thanks to multi-function drills that spot and countersink. 6. ReamersReamers are mainly utilized to enlarge the existing holes in compliance with the tolerance while providing a superior surface finish. They help you ensure the accuracy of the roundness and diameter of a drilled hole. For reamers to work, a pilot hole of roughly the same diameter as the final product must first be bored. 7. Taps and Thread MillsTaps are tools used to cut threads into the interior of a material. Yet not every thread is produced by a cutting procedure. By applying pressure, Roll Form taps get inserted into holes, and the surrounding material is shaped to fit them. Thread mills are similar but can be employed to cut internal or external threads. Concluding RemarksThe key to successfully machining products and components is selecting the appropriate CNC tool. Learn how each one functions, and keep in mind the use of the most beneficial ones in your manufacturing facility. About the AuthorPeter Jacobs is the Senior Director of Marketing at CNC Masters. He is actively involved in manufacturing processes and regularly contributes his insights for various blogs in CNC machining, 3D printing, rapid tooling, injection molding, metal casting, and manufacturing in general.
Technical Blog courtesy of Techniks USA Edited and amended by Bernard Martin  If you work in the metalcutting, signmaking or cabinet making manufacturing industry, the term “collets” is already very familiar to you. There are many types of collets used in many different industries and applications. This article is focused on collets used in rotary tool holders found in CNC milling machining centers and CNC Routers and also used in CNC Lathes and Swiss Style CNC's. Let's cover the basics: What are Collets?Collets are the critical connection between the cutting tool and the tool holder, also called a collet chuck. Most collets are round, cone-shaped, and slotted. Collets encircle the cutting tool shank to evenly distribute holding power around its center bore. Before getting too deep into the technical aspect of collets, It's going to be helpful to anyone new to the use of collets to understand the basic anatomy of collets and of a collet chuck system. How Collets Work Collet ins depicted being held in a CAT 40 rotary collet chuck toolholder used in CNC milling machines. The tapered collet base is made to fit into the collet pocket of the collet chuck body. The free release locking tapered (16°included, 8° per side) design of the collet base and collet pocket allows the collet to be centered in the pocket as it is pushed in by the collet nut on the lead face during setup.
This centering effect enables the collet to achieve a high degree of accuracy (concentricity); much more than drill chucks and side-lock style end mill holders. As he collet nut is tightened down on the collet, it is pushed into the pocket collet chuck pocket. The slots in the collet allow the I.D. bore to collapse and apply clamping pressure to the cutting tool shank. It's essentially a spring that is compressed tight around the shank of the cutting tool such as a drill or end mill. The result is a very strong and rigid clamping force on the cutting tool. Since the collet base is tapered to match the collet pocket, tool runout (T.I.R.) is reduced. Total indicator runout (TIR) is a term often used in manufacturing, especially when dealing with rotating parts such as cutting tools, particularly endmills and drills. TIR is defined as the difference between the maximum and minimum values measured across an entire rotating surface about a reference axis. |
Technical Support BlogAt Next Generation Tool we often run into many of the same technical questions from different customers. This section should answer many of your most common questions.
We set up this special blog for the most commonly asked questions and machinist data tables for your easy reference. If you've got a question that's not answered here, then just send us a quick note via email or reach one of us on our CONTACTS page here on the website AuthorshipOur technical section is written by several different people. Sometimes, it's from our team here at Next Generation Tooling & at other times it's by one of the innovative manufacturer's we represent in California and Nevada. Archives
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